We ferment tobacco at home. Tobacco fermentation from A to Z complete raw material processing process

Chapter 7. TOBACCO FERMENTATION

The fermentation process is the final stage in post-harvest processing of tobacco. At this time, the main biochemical and chemical transformations of its composition are largely completed, developing and consolidating the commercial and smoking advantages of raw tobacco. Fermented tobacco is suitable for long-term storage and can be used to prepare smoking products.

7.1.The essence of the fermentation process.

During the fermentation of tobacco, a complex set of changes occurs in its chemical composition and water-physical properties. This significantly affects its appearance, smoking qualities and technological properties.

During fermentation, the light green color remaining on the leaves after drying disappears. Dark greens acquire brown and olive shades. In the main color, dark tones (orange, red, brown) are somewhat enhanced. Instead of a damp, grassy smell, a specific pleasant tobacco smell appears. These changes noticeably even out the color of the tobacco and improve its color value and aroma.

Changes in the chemical composition of tobacco during fermentation (formation of melanoidin and destruction of pectin substances, amino acids and nicotine, qualitative changes in resins and essential oils) improve its taste and aroma: the strength decreases, tobacco becomes softer when smoking, and loses its bitterness to some extent. At the same time, the aromatic properties of smoke improve and the flammability of tobacco increases.

During fermentation, the ability of tobacco to absorb moisture from the air and retain it (moisture capacity) is significantly weakened, and the ability to warm up and self-hydrate is lost. Raw tobacco becomes more resistant to mold and suitable for long-term storage, transportation and processing in factories.

These changes in tobacco during fermentation are accompanied by a loss of its mass. “Shrinkage” occurs due to a decrease in dry matter and water and amounts to 10-12%. Losses of dry matter by tobacco during fermentation range from 1.5 to 3.5%.

There are several views on the nature of the tobacco fermentation process. Most correctly, in our opinion, the essence of the process is reflected by the enzymatic theory developed by prof. A.I. Smirnov. According to this theory, both purely chemical and biochemical reactions take part in changing the composition of tobacco during fermentation. The latter, as is known, occur with the participation of organic catalysts (reaction accelerators) enzymes.

In addition, during the fermentation of tobacco, changes in the chemical composition occur due to the volatilization of substances in a gaseous state (nicotine, etc.).

7.2. Fermentation modes.

Initially, the fermentation technological regime took place at relatively low tobacco temperatures - 30-35°C. Essentially, the temperature conditions of this regime corresponded to the usual temperature ranges of seasonal warehouse fermentation. The humidity of the tobacco was set at a level at which the development of molds during fermentation was excluded. The moisture content of tobacco corresponded to its equilibrium state with a relative air humidity of 75% at the regime temperature.

Along with the development of the fermentation industry, tobacco fermentation regimes also underwent changes. The regime at a temperature of 35° was no longer satisfactory for production, since it required rather long (about 35 days) fermentation periods.

Practice has followed the path of gradually increasing the temperature of the fermentation mode. Since 1930, the generally accepted fermentation temperature has become 40°C.

Over time, in the practice of factory fermentation, increased temperature conditions and lower air humidity began to be used. As a result, it turned out that treating tobacco at a 50° mode until it loses the ability to absorb oxygen from the air gives a product with smoking qualities close to tobacco fermented at a 35° mode. The use of the 60° mode leads to a deterioration in the smoking and technological advantages of high-quality tobaccos. Since the 50° fermentation mode is economically more profitable (it reduces fermentation time by more than 2 times), therefore this mode was introduced into the practice of fermentation plants as the main one for the fermentation of all types of tobacco. In addition to reducing fermentation time, the 50° mode eliminates the development of mold, which greatly simplifies the technological process. Of great importance in this mode is the ability to quickly process defective and highly moist tobacco.

However, high-grade tobacco, especially the blended type, requires milder fermentation regimes to obtain raw materials with maximum development of quality characteristics, both in terms of taste and aroma, and water-physical properties.

Technological process 50° - fermentation mode. Currently, all fermentation plants use a 50° fermentation regime. In essence, this mode differs in many respects from the method of fermenting tobacco at 35°. As indicated, tobacco fermentation at low temperatures occurs over a fairly long period of time, and the individual characteristics of tobacco bales are manifested to a sufficient extent. At 50° mode, the manifestation of the individual properties of the bale is largely leveled out. The entire mass of tobacco loaded into the chamber is heated to 50° and simultaneously dried.

Differences in the behavior of bales are determined mainly by the degree of compaction, size and moisture content of the tobacco. Therefore, if uniform coefficients of moisture and thermal conductivity were established for the entire mass of tobacco loaded into the chamber, the 50° fermentation mode could be carried out according to a predetermined schedule. In some cases, with a strict selection of a batch of tobacco, an experienced fermentation technologist can now, with some approximation, establish a program schedule for the regime.

The 50° fermentation mode is carried out in three phases. The implementation of each of them has its own characteristics associated with the nature of the raw materials loaded for fermentation.

First phase is preparatory and consists of raising the air temperature in the chamber to 50° and warming up the tobacco. However, preparation for the second phase involves more than just warming up the tobacco. When heating tobacco, you cannot dry it out or over-moisten it at the same time. Deviations in humidity, both in one direction and in the other, worsen the conditions for fermentation in the second phase. Therefore, the rise in chamber air temperature in the first phase must be combined with its certain moisture content.

The heating rate is determined by the temperature difference between the tobacco and the chamber air and, in addition, by the thermal properties of the bale, which depend on the humidity and degree of compaction of the leaves. At this time, during the heating process of tobacco, the relative air humidity is maintained at 50-60%, so that the surface of the bales does not dry out.

For dry, low-material tobacco, you can raise the air temperature in the chamber, approaching the maximum permissible temperature difference. This value depends on the quality of the tobacco and its moisture content, the structure of the bale and the relative humidity of the chamber air. When loading material tobacco of normal humidity into the chamber, the limit value is dangerous. If the highest grades of light-colored tobacco with large leaves and high moisture capacity are fermented, then the rise in temperature is extended over a longer period, and the temperature difference is only 3-4°.

According to the heating rate of the chamber, the timing of the first phase changes. For low-quality coarse tobacco, as well as dry and low-material tobacco, the first phase lasts from 48 to 60 hours; for medium-quality tobacco, the time period is correspondingly extended - 70-80 hours, and in the case of fermentation of light tobacco of the highest grades, the first phase is extended by 4-5 days.

If “sick” tobacco is loaded into the chamber, that is, bales that are very waterlogged and begin to mold, then in the first phase the temperature is quickly raised. In this case, they strive to quickly heat the bales to the maximum temperature of the regime, and then, by drying them, bring them to their normal state. High temperature eliminates the risk of molding, and for this reason the possibility of some darkening of the tobacco is neglected.

The tobacco must be heated evenly in all areas of the chamber. To ensure uniform heating, the direction of air supply is changed from time to time - air is pumped into the chamber alternately through the upper and lower air ducts.

Second phase is the fermentation phase itself, when corresponding changes in composition occur in tobacco heated to 50°. The beginning of the second phase cannot be strictly separated from the end of the first. There is a well-known transition from one state to another, since already at a temperature of 40-45° the fermentation process develops with sufficient intensity. The end of the first phase and the beginning of the second is characterized by a significant formation of excess moisture, which, increasing the moisture saturation of tobacco, can lead to a strong darkening of the color of the leaves.

Therefore, during the transition from the first phase of fermentation to the second, depending on the condition of the tobacco, the relative humidity of the chamber air is changed. The actual implementation of the second phase consists of regulating air humidity, since the temperature during this period is usually maintained at a constant level of 50°, and the mode options differ only in the relative air humidity.

Depending on the air humidity regime in the second phase, fermentation can be divided into three types - dry, normal and wet.

In dry fermentation mode, the relative air humidity in the chamber during the first period of the second phase is maintained at 35-40%.

This mode is usually applied to moist tobacco packed quite tightly into a bale. In this mode, the tobacco dries out greatly from the surface, which leads to large losses, since the dried tobacco is poorly moistened and breaks down during unloading, forming a large amount of pharmaceuticals. In dry mode, the temperature in the bales is always 4-5° below the ambient temperature, since some heat is consumed by the tobacco to evaporate moisture.

Tobaccos with normal moisture content are fermented under conditions of relative air humidity of 60-65%. At this humidity, the tobacco does not dry out; excess moisture is removed at a sufficient speed. The temperature in bales at this air humidity is usually close to 50°C or slightly lower (by 1.0-1.5°).

Dry, overripe or low-material tobacco is fermented under wet conditions. In this case, the air humidity in the chamber is maintained at 70-75%. At this air humidity, tobacco usually has the temperature of the chamber air.

On average, the second phase of fermentation lasts about 5-6 days. Depending on the applied relative humidity regime, the timing of the second phase may vary. Usually, in dry mode, the period is extended by 2-3 days. Towards the end of the second phase, as the process fades, the self-hydration of tobacco decreases. To prevent the tobacco from drying out, the air humidity is slightly increased towards the end of the second phase (up to 70-75%). Of course, this is done if the condition of the tobacco requires it.

Third phase fermentation occurs after the process has finished. In the third phase, the fermented tobacco is prepared for unloading; the temperature inside the chamber decreases while the tobacco is slightly moistened. If in the first phase there was a danger of tobacco being over-moistened, then in the third phase there is a danger of the opposite order. If the process is carried out incorrectly, the tobacco can dry out suddenly. This can happen if the chamber air cools too quickly. At the same time, bales of tobacco, having a temperature of about 50°, due to low thermal conductivity, do not have time to cool as quickly as the air in the chamber. The temperature in the bales in the third phase becomes significantly higher than the air temperature of the chamber.

The tobacco in the bale begins to dry out quickly. To avoid drying it out, the chamber is cooled slowly while humidifying the air. Air humidity in the third phase is adjusted to 70-80%, depending on the condition of the tobacco. The duration of the third phase ranges from 2 to 4 days. The tobacco is cooled to a temperature of 20-25°C. Its humidity by the end of the third phase should be 14-16%.

After cooling, the tobacco is unloaded from the chamber into the workshop after fermentation treatment.

Technological process 60° - fermentation mode. For some low-quality and coarse-skeleton tobacco, along with a 50° fermentation regime, a 60° regime is used.

Tobacco of the highest commercial grades, as well as aromatic tobacco of the Crimea, is prohibited from fermenting in this mode, since the 60° fermentation mode deteriorates the quality of tobacco raw materials. Therefore, it is undesirable to process even light varieties of skeletal-type tobacco, which is the main raw material for the production of smoking products for mass consumption, using the 60° regime.

The economic efficiency of the 60° fermentation regime is questionable. If the 50° mode compared to 35° reduced the fermentation process time by 2-2.5 times, then 60° fermentation compared to 50° reduced it by only 20-30% with significant heat consumption.

The technique for performing the 60° fermentation mode is the same as the 50° mode. The process is divided into three phases. Usually the process is accelerated by reducing the timing of the second phase.

Specialists from the Maikop fermentation plant proposed improved 50° and 60° tobacco fermentation modes, in which the second fermentation period ends not when the tobacco is fully fermented, but somewhat earlier. The third period is used not only for cooling and normalizing the moisture content of tobacco, but also for its own fermentation. Tobacco is unloaded from the chamber when it is completely fermented according to organoleptic characteristics.

Improved tobacco fermentation modes reduce the duration of the process by 1-3 days; reduce fuel and electricity consumption, losses of raw materials from the formation of pharmaceuticals; facilitate drying of moist tobacco and conditioning it by humidity towards the end of the process; exclude the phenomenon of “refermentation” of tobacco, which causes darkening of color and deterioration of the water-physical properties of tobacco.

For better drying of highly humid tobacco, with improved fermentation modes, after heating it to the temperature of the given mode (in the second fermentation period), the ambient air temperature is quickly reduced to 40-45° (with a humidity of 55-60%). Then it is maintained at this level until the temperature inside the bale (bale) drops to this value or close to it. Then the tobacco is heated again to the temperature of the given mode and cooled to 40-45°, etc. The number of such cycles depends on the initial moisture content of the tobacco. This technique provides additional drying of the tobacco during the second fermentation period.

During fermentation, constant monitoring of fermentation modes and the condition of the tobacco is carried out. Temperature and humidity are measured, as well as temperatures inside the bales. From time to time, the moisture content in tobacco is determined by organoleptic or laboratory methods. At the end of the second period, samples are taken to determine the fermentation of tobacco based on the oxygen index and organoleptic characteristics. At the end of the process (before unloading tobacco from the chamber or installation), the moisture content of the fermented tobacco is determined

7.3. Tobacco fermentation technology.

Selection of tobacco batches for fermentation. Given the wide variety of bales in volume and structure, the most homogeneous batch of tobacco is selected for fermentation. The selection of bales is carried out at the warehouses of the fermentation plant. For loading into the chamber, tobaccos of one botanical variety and one drying method are selected. Semi-cured tobacco is loaded with solar-cured tobacco. Various botanical varieties of tobacco are allowed to be loaded into the chamber at the same time if they are similar in leaf size and materiality.

Since tobacco behaves differently during fermentation depending on tissue density and maturity, plants of the same massiveness and maturity are selected for the batch. It is allowed to load the chamber with tobacco of similar commercial varieties, for example grades 1, 2 and 3 with the same materiality of the leaves. If there are not enough bales of the first grades of tobacco, you can add 4 grades of tobacco to the chamber. However, in this case, the fermentation regime is established for higher varieties.

The uniformity of tobacco moisture content is of great importance. It is, of course, difficult to select tobacco of the same moisture content, and therefore bales according to this criterion are divided into several close groups. Tobacco with a moisture content of up to 14% is considered dry, tobacco with a moisture content of 14 to 18% is considered normal, and above 18% is considered highly humid. To load into the chamber, tobacco of only one humidity group is selected. It is allowed to load bales together when humidity fluctuates within 4%.

To load into the chamber, it is necessary to select bales that are similar in weight. This creates a certain homogeneity of the bales in structure. Unripe tobacco, damaged by diseases and pests, is separated into separate batches.

Preparatory workshop directly connected to the warehouse and fermentation workshop. The task of the workshop is to carefully prepare a batch of tobacco for loading into the fermentation chamber. If the warehouse and fermentation chambers are located in the same building, the work carried out in the preparation workshop can be successfully combined with the work of the main warehouse.

In the preparatory workshop, trolleys or hanging shelves are loaded with tobacco. Therefore, when calculating the workshop area, a place is provided for their placement. The area of ​​the preparatory workshop must ensure the storage (aging) of tobacco intended for loading into the chamber for three days. Thus, the production area of ​​the workshop is determined by the capacity of the chambers, their number, average camera turnover times and the accepted method of loading tobacco.

The workshop premises are air-conditioned. The temperature is maintained at 18-20°C, humidity – 60-65%. Under these conditions, tobacco received from cold warehouses is heated to the workshop temperature during a three-day resting period, which ensures that the initial temperature difference in the first phase of fermentation is reduced to a minimum.

In the preparatory workshop, if necessary, I press grade 5 tobacco and low-material, dry tobacco grade 4 before loading them into the chamber. Pre-pressing is done to increase the loading capacity of the chambers.

Two days before loading tobacco into the chamber, the humidity of the prepared batch is determined in the factory laboratory. The stacking of tobacco in the workshop is usual - in threes or in 2 tiers.

The preparatory workshop is connected to the fermentation workshop by internal transport means (belt conveyors, carts, etc.). In the same way, the workshop must be connected to the warehouse.

Fermentation shop. Tobacco is fermented in a factory method in climate chambers or in Kelleev installations. The fermentation shop consists of several fermentation chambers, the number of which is determined by the design capacity of the plant. Thus, the fermentation chamber is the main object of the workshop, its technological unit.

Fermentation chamber- this is a specially equipped room in which, with the help of air conditioning devices, the necessary air parameters can be created and maintained throughout the entire period provided for by the technological process.

The cameras are placed inside the factory box. Along their walls on both sides there are corridors for loading and unloading tobacco. Conveyor belts are located here or monorails pass through to move shelves with tobacco. The chamber capacity is based on the real possibility of selecting a homogeneous batch of tobacco. To accommodate bales and bales of tobacco, the chamber has stationary or mobile racks. Bales are placed on racks on the stem side.

A cross section of a fermentation chamber with hanging shelves is shown in Fig. 70.

There should be no protrusions, nooks, or columns in the chamber, that is, areas that interfere with the uniform distribution of air. The air supplied from the air conditioner must be evenly distributed throughout the entire chamber. The discrepancy in temperature is allowed no more than 1-2° and in air humidity - 3-5%.

The heating and ventilation system must have the power necessary to fulfill the technological requirements, that is, it must ensure that the temperature in the chamber rises to 60° within 24 hours while simultaneously reducing air humidity to 40%. These conditions satisfy the implementation of the first phase with maximum acceleration of the process.

Rice. 70. Cross section of a fermentation chamber with hanging shelves:

1 - hanging shelf; 2 - bale of tobacco; 3 - cast iron pendant

Paths; 4 - wooden beam for fastening the pendants; 5 - underground room

for intra-chamber heating and lower air ducts.

The humidification installation must ensure air saturation with moisture up to 80% at a temperature of 60° and maintain humidity at this level while simultaneously reducing the temperature to 25°. Such conditions arise in the third phase of the process.

The cells are equipped with individual air conditioners, internal heating, air ducts and automatic regulators.

Kelleyev installation for tobacco fermentation it is a tunnel in which trolleys with bales and bales of tobacco move along a narrow-gauge rail track. The length of the tunnel is divided into 12 compartments. In each of them, constant temperature and air humidity are maintained, which correspond to the accepted tobacco fermentation regimes. The first phase of fermentation takes place in 1-4 compartments of the tunnel. In the first compartment, the temperature is maintained at 35° (at 50-degree mode) or 40° (at 60-degree mode). The second fermentation period is carried out in 5-8 tunnel compartments, and the third - in 9-12 tunnel compartments.

Trolleys with tobacco, moving along the tunnel, are exposed to the air of each compartment; the air parameters are selected in such a way that their sequential change along the length of the tunnel corresponds to the full technological cycle. The movement of carts with tobacco in the tunnel is carried out by a screw pusher located at the beginning of the tunnel. Carts with unfermented tobacco are fed into the tunnel periodically - every 5-10 hours.

IN Post-fermentation processing workshop The fermented tobacco is cooled for 2-3 days and then subjected to general sorting in accordance with the requirements of the current standard for fermented yellow leaf tobacco. Bales (bales) are carefully examined, tobacco with fermentation and other defects is separated and sent for processing. The rest of the tobacco is classified into commercial grades and laid out (bales in a cage 4-5 tiers high) for a period of at least 25 days.

Leaving equalizes the moisture content of tobacco, improves its aroma and elasticity. The results of general sorting are documented in accordance with the instructions for tobacco accounting at fermentation plants.

After resting, the tobacco bales are pressed and lined in a row, and the bales are tied with twine (centered) and the sides are covered with kraft paper or sewn up in a row; then carloads of tobacco are formed for shipment to factories.

Pressing and wrapping tobacco reduces the bale volume by 30-40%, reduces the consumption of packaging materials, increases its safety during long-term storage and transportation, and reduces losses of raw materials from mechanical damage.

During the processing of tobacco in fermentation plants, a certain amount of waste is generated in the form of fragments and leaf stalks (pharmaceuticals). The waste is collected (unfermented - fermented), purified and, using a pharmaceutical purifier, divided into substandard and standard. The latter are used in the manufacture of smoking products in factories.

Aging of tobacco. During long-term storage (aging) of fermented tobacco, processes of compositional changes continue in it, developing very slowly, without noticeable external manifestations. As a result, for some time there has been a further significant improvement in the quality of tobacco, both in composition and physical properties. The taste becomes softer and purer, the aroma of smoke and the aroma of tobacco are significantly enhanced; the remnants of greenery disappear and the color evens out; the flammability, elasticity and fibrous properties of tobacco increase.

The process of slowly improving the quality of tobacco during long-term storage is called aging.

When aging, bales of tobacco are stored in warehouses of fermentation plants and tobacco factories under natural conditions, preferably at a temperature of 17-20° and air humidity of 65-70%. The total duration of the process is 1-2 years, depending on the properties of the tobacco. Resinous aromatic tobacco of types I and III (Dyubek, Ostrokonets) with dense leaf blade tissue from all growing areas and type II tobacco (American) from the Crimean region improves quality within 24 months. In type IV skeletal tobacco from all growing areas, aging takes place within 18 months, and in aromatic and skeletal tobacco with non-resinous leaf blades and loose tissue, aging takes place within 12 months. With longer aging, the commercial and smoking advantages of tobacco decrease.

Tobacco of 1, 2 and 3 light commercial grades with a moisture content of 12-15% is used for aging. Tobacco damaged by warehouse pests (fireworm, tobacco beetle) is not allowed to be stored for aging.

Bales and bales of tobacco are placed in a stack - in a cage or in parallel rows (stiff) in four tiers (resinous aromatic and skeletal tobacco with dense leaf blade tissue) or in five tiers (the rest of the tobacco). The stacks are made up of tobacco of the same botanical and commercial grade, of the same resin content and density. Passages are left between the stacks to monitor the condition of the tobacco (its temperature and humidity).

4.2. Tobacco drying technology.

Tobacco languishing. During languishing, the leaves lose 20-25%; water, but remain alive. In them, starch is completely destroyed, the amount of proteins is reduced by 30-35%, the nicotine content of essential oils increases, which significantly improves the taste, aroma and aroma of raw tobacco. When languishing, chlorophyll is also destroyed, the green color of the leaves changes to yellow, moisture capacity decreases and the raw material becomes more resistant to mold. These changes are accompanied by a loss of dry matter in tobacco leaves in the amount of 10-16%.

The simmering of tobacco is influenced by temperature, air humidity and the speed of its movement. The temperature during simmering can be increased to 40°C; at temperatures above 40°, the leaf quickly dies and loses its quality (steamed). During the first period of languor, when the leaves still contain a lot of water, the temperature should be increased gradually so that the leaves wilt well.

At temperatures up to 40°, the tobacco leaf loses water faster and turns yellow evenly. However, this temperature should only be used when simmering coarse tobacco, in which the leaf blade ripens unevenly.

With increased ventilation, tobacco accelerates water loss and yellowing of leaves during languor. However, in this case the yellow color spreads unevenly across the leaf blade. Therefore, at the beginning of simmering of tobacco, in which the leaf blade ripens unevenly, the drying room should not be heavily ventilated, so as not to reduce air humidity. At the end of simmering and during subsequent drying, simultaneously with the rise in temperature, it is necessary to reduce the air humidity, increasing the ventilation of the drying room in order to avoid “steaming” the tobacco.

Favorable conditions for simmering tobacco are a temperature of 25-35°, air humidity of 70-90% and a speed of movement not higher than 0.3 m/sec. The room should be ventilated periodically to remove excess moisture.

There are several ways to simmer tobacco. During solar drying, simmering is carried out in heaps before the leaves are strung on cords, simmering on cords and simmering of leaves strung on cords and hung on frames.

Tobacco languishes in heaps(garmanach). This method is as follows. Tobacco delivered to the barn is laid out on a moistened adobe floor from left to right in one layer in dense rows 1.3-1.5 m wide. This is done carefully so as not to disturb the arrangement of the leaves in the packs or damage them. Leaves should never be left unshaded in the sun, as they can burn and become steamy.

If tobacco is strung on the day of withdrawal, the leaves are laid with the petioles facing up. If it is strung the next day after delivery from the field, then the leaves are laid with the petioles down (towards the floor). Leaves with yellowed tops are laid in the same way so that they do not darken.

In warm, humid weather, tobacco simmers well without shelter. In cold or windy weather it should be covered with matting or rows. After 12-14 hours, the tobacco warms up as a result of intense breathing and heat generation. This indicates that the languishing process is intense. To avoid spoilage from accumulated breath products (excessive accumulation of CO2), tobacco should be ventilated. Ventilation is carried out by repositioning it. At the same time, the moisture accumulated inside the mass is removed, the air is renewed, in addition, the leaves that were on top fall inside the mass of tobacco, and their place is taken by leaves from the inside of the harman. When simmering tobacco in heaps, you must carefully monitor the temperature inside the mass of tobacco (usually it should not be allowed to be higher than 25-30°).

The languishing period in garmans is about 2-3 days. If tobacco, which has a delicate and juicy tissue, languishes, the languor passes quickly. Coarse or dense tobacco simmers longer.

At the end of the languor, which is recognized by the color of the leaf (yellowish color, spreading to one third of the leaf blade), the harmand is disassembled and the tobacco leaves are strung on a cord. In this case, you should sort the leaves according to the degree of exhaustion and string them separately. It is not necessary to allow the leaves to turn completely yellow, since at this time they begin to die and, with a high water content, oxidative processes rapidly develop in them, leading to a strong darkening of the color.

The method of simmering tobacco in garmans has many disadvantages. These include, first of all, the need for careful observation and shifting, which requires unnecessary labor costs. In addition, simmering tobacco for two days requires a large area of ​​the barn. Tobacco leaves that have withered during simmering are much more difficult to string, resulting in reduced labor productivity. Therefore, this method of languishing, as a rule, is not currently used. However, in the absence of fire dryers, in case of cold windy weather, tobacco can be dried out quite successfully in covered garmans. The advantage of this method is that by using sorting after languishing, you can select leaves that are uniform in languor for the cord - this greatly facilitates drying and subsequent processing .

Languishing on the cords. Simmering tobacco leaves on cords before hanging them on frames proceeds basically the same way as in garmans. The disadvantages of this method include the fact that the leaves on the cords wrinkle and stick together and their quality deteriorates. The ends of the leaves (the top of the leaf) are especially damaged, since tobacco on cords is laid with the petioles facing up for simmering. The advantage of this method is its greater simplicity compared to simmering in heaps before stringing.

Low tobacco. Leaves are strung onto twine manually with a needle 60-70 cm long, or using special machines, which increases labor productivity. The petioles should be slightly dried before stringing. Leaves collected after rain should be strung the next day after breaking.

During the stringing process, the leaves are sorted, putting aside very large and too small leaves, overripe and underripe, severely affected by diseases and damaged by pests. Then they are strung on cords, without mixing large leaves with small ones, overripe with unripe, etc., which not only facilitates the sorting and delivery of tobacco to collection points, but also ensures normal drying and fermentation.

When stringing tobacco on a cord with a needle, bunches of leaves are placed on the knee, then 2-3 leaves are taken and strung one at a time onto the needle, piercing the stem below the base. After filling the needle, the tobacco is released onto the cord. The leaves lowered from the needle onto the cord are evenly distributed along its entire length, or, as they say, they are broken on the cord. Standard cord length is 5.6 m.

The density of stringing leaves on cords depends on the characteristics of the tobacco and the drying method. The following density for stringing tobacco is recommended with a cord length of 5.6 m and a needle of 70 cm. With the solar drying method and drying, the leaves of the first and second breaks, small leaves, as well as ripened and harvested in dry weather, are strung on a cord with 5-6 needles. The leaves of the rest are brittle, large leaves and harvested in wet weather - 4-5 needles each. On the southern coast of Crimea and in other areas of dry climate, you can string one more needle on the cord. With complete fire drying and semi-drying, the leaves are strung somewhat thicker: the leaves of the lower brittle and small ones - 6-7 needles each, the leaves of the remaining brittles and large ones - 5-6 needles each. Unripe, overripe or over-exhausted leaves are threaded less frequently than technically mature and normally exhausted leaves.

When manually stringing, a table-machine is used to lower tobacco leaves from a needle onto a cord. To do this, threading needles have a round hole in the center of the front spear-shaped part, and at the opposite end there is a side slot for threading a loop of cord on which tobacco is threaded. The table-machine (Fig. 6) has 60-70 cm high stands at the edges. A needle holder is fixed on one stand, and a twine holder on the other.

The needle holder consists of a durable metal plate into which two metal pins are embedded. The plate is secured with four screws to the machine stand on the left. When lowering the leaves from the needle onto the cord, the needle is put on one of the pins of the plate with a hole at its sharp end. A loop of twine is secured in the slot at the opposite end of the needle, and its other end is secured in the twine holder. The latter is a bent springy metal plate with a wedge-shaped slot into which the end of the twine is inserted for fastening. The plate is mounted on the second rack of the machine on the right at the same height as the needle holder.

Rice. 6. Table-machine for lowering leaves from a needle onto a cord:

I - clamp, 2 - needle holder , 3 - needle , 4 - twine holder

Two people work at the machine: one secures the needle with strung leaves, and the other - the twine. Then the first one lowers the leaves from the needle onto the cord, the second breaks them down to the required density. To make it easier to move leaves from the needle to the cord, use a “brush” clamp. The clamp is made from two boards, loosely connected to each other on one side with two pieces of leather. The inner surface of the boards is ribbed to better hold the leaves.

In Crimea, when stringing small-leaf tobacco, a regular needle is used, and a simplified trestle table is used to lower the leaves from the needle onto the cord. When the leaves fall from the needle, the worker presses them on the table with his hand.

When using cutting machines, packs of tobacco leaves are manually evenly placed on the feeding conveyor and leveled in a layer of one or two leaves, petiole to petiole. Depending on the design of the machine, the leaves are secured by sewing them to the base or with one thread (without the base) with a chain stitch that easily unravels. This seam opens easily after drying the tobacco. When operating the machine, care must be taken not to allow two or three leaves to be secured in one loop. The place where the leaf is fixed must be at a distance of at least 6 mm from the end of the petiole. The machine produces a cord on which the leaves are firmly attached and their loss during hanging and drying does not exceed 5%.

Various models of tobacco sewing machines have been created for sewing tobacco leaves: “Kuban”, “Kriulyanka-3”, “Apsheron”, MZL-1, TPM-69M, etc.

The tobacco sewing machine "Kuban" consists of a frame, a loading device, feeder, outlet and take-out conveyors, a leaf pack divider, flattening rollers, a sewing mechanism, and an electric motor drive. The loading device is designed to accumulate and feed leaves onto the conveyor. From it, the petioles are captured by the feeding conveyor belts and moved to the divider. The latter moves the packs apart and places the leaves in one row. Having passed the divider, the petioles form one row and are at a certain distance from each other. Flattening rollers change the shape of the petioles, giving them a certain thickness. The sewing mechanism serves to secure the leaves to the cord using a chain stitch. The outlet conveyor moves the cord with the tobacco sewn to it, and the external conveyor is designed to transport finished cords. In addition, the machine is equipped with a device that cuts cords of any length.

The TPM-69M tobacco sewing machine (Fig. 7) has variable feed conveyor speed, feed pitch and number of needle strokes. The machine is equipped with a signaling device for monitoring and adjusting the length of the cord.

Fig.7. Machine for fastening leaves on cords TPM-69M.

To string tobacco leaves from 1 hectare of planting, manual stringing requires 10-16 kg of twine (for a yield of 15 quintals), while machine stringing requires different types and quantities of cotton thread in accordance with the design of the machine.

After stringing, leaves contaminated with sand and soil are washed in running water or ponds. They are then hung on frames and dried in the shade. Exhausted tobacco cannot be washed, as with further drying it darkens and loses its quality.

Languishing on the frames . This method of simmering is the simplest and most convenient. After stringing, the tobacco is hung on frames: each frame has 20-25 cords (depending on the size of the leaves). Medium-leaf large-leaf tobacco is hung on frames with only 20 cords. The leaves of the upper brittles, which are smaller in size, or the leaves of small-leaved varieties allow you to increase the number of cords on the car to 24-25.

The frames with hanging cords in the tobacco barn are moved as close to each other as possible and left in this position for 2-3 days, that is, until the end of languishing. When the bulk of the leaves acquire a light green color with a yellowish tint, the frames are pulled out of the barn into the sun.

During the first days, the frames should be pulled out during the cooler morning and evening hours. Under these conditions, the loss of moisture will be moderate and the simmering of the tobacco (with simultaneous drying of the leaves) can be completed after the yellow tones have spread to most of the leaf blade. At this time, the frames are left in the sun all day, putting them in the shed only at night. This must be done, since dew, settling on the leaves and excessively moistening the tobacco, increases the darkening of the color and can lead to a sharp decrease in the quality of the material.

Simmering on frames is currently used as the main method - “barn” simmering. Its advantages are as follows:

– the least losses from mechanical damage, since the tobacco strung on a cord is immediately hung on the frames and further operations are carried out with the whole frame of tobacco;

– higher productivity when stringing fresh tobacco and subsequent work with it;

– good aeration of leaves during simmering.

However, this method of simmering should not be used in cold or windy weather, since tobacco in this case is difficult to simmer due to the low temperature, and in strong winds and low air humidity it can dry out prematurely, maintaining a green color, which later turns into brown.

In areas with a dry climate, tobacco simmering due to rapid loss of moisture does not occur completely, so it is better to carry it out in basements. Due to the lower temperature and increased air humidity in the basement, the conditions necessary for simmering tobacco are created.

Sometimes the following technique is used. Wanting to speed up the simmering process, after hanging the cords, the frames are rolled out in the sun for a while, and when the tobacco warms up, they are rolled back into the barn. In warm, humid weather, well-ripened tobacco from poor soils can be dried with only a slight simmer. In this case, warm weather and moderate loss of water will ensure normal simmering of the tobacco at the same time as drying.

Hanging tobacco on frames. Cords with tobacco are hung on frames (cars). Tobacco of one botanical variety, collected from one site, one cutting with the same degree of maturity, is hung on each frame.

When hanging tobacco, you need to make sure that the leaves at the cuts and the edges of the frames are not thickened, which leads to an extension of the drying time (by 10-15 hours with the fire method and 2-3 days with the sun). In places where it thickens, tobacco steams when dried by fire, and when dried in the sun it darkens or even rots.

During full fire drying and semi-drying, the cords with tobacco are hung thicker on the frame in the part that will be located near the ceiling of the dryer, where the temperature is higher. The bottom cord should not be in tight contact with the frame axis. This speeds up the drying of tobacco and ensures the production of high quality raw materials.

The number of cords hung on the frame depends on the size of the tobacco leaves. On each frame measuring 2.8 x 5.6 m, hang 16-18 cords of large-leaf tobacco, 20-23 of medium-leaf tobacco and 25-28 cords of small-leaf tobacco. On a frame measuring 3X4 m, hang 1-2 more cords.

To facilitate the preparation of batches for drying and reduce labor costs, frames with uniform tobacco must be placed in one compartment (the “eye”) of the tobacco barn.

Before loading tobacco into the dryer, it is necessary to tighten the cords that are hanging on the frames, since when the cords sag, the tobacco dries more slowly and is often subject to steaming.

Two people pull the cord. They stand on both sides of the frame, untie the ends of the cord, pull it with equal effort and secure it to the frame, and then move on to the next one.

Languishing in garlands(Fig. 8). When drying tobacco in the form of vertical garlands, it is simmered under special canopies. Along with the positive qualities of this method - high productivity with machine cutting of tobacco and good aeration of the leaves during simmering - there is also a significant drawback. At low ambient temperatures, tobacco is difficult to simmer. And with low air humidity and strong winds, it can dry out prematurely, while maintaining its green color.

Simmering in fire tube dryers. In a fire dryer, tobacco goes through the entire drying process from the very beginning, that is, it is subjected to simmering and subsequent drying. Immediately after stringing, the tobacco is hung on wagons and loaded into dryers. The gate through which tobacco is loaded is carefully closed.

Tobacco simmering begins at a temperature of 30-35°. To maintain this temperature inside the dryer, the heating system is turned on. Tobacco languishing is the process of changing the composition of tobacco leaves that retain viability. The air temperature in this phase of the process should not be greatly increased. In addition, during simmering, tobacco leaves lose some water. However, this loss should not exceed the limit beyond which the leaf tissue dies from dehydration. The most favorable rate of moisture transfer is such that by the end of simmering the tobacco leaves will approach the maximum water deficit, but will not go beyond it. Typically, during simmering, tobacco loses about 30-35% of its original mass.

Rice. 8. Placing tobacco in vertical garlands

In accordance with this, the air in the dryer during the simmering phase is maintained with a certain moisture saturation. At the beginning of simmering, the relative air humidity should be at 75-80%. Consequently, the languishing phase begins at 30-35° and relative air humidity of 75-80%.

This combination of temperature and air humidity in the dryer is maintained until a yellow color appears at the top of the sheet. The appearance of a yellow color is a sign of some fatigue. The exhausted part of the leaf, which is on the verge of dying, should be slightly dried, at the same time it is necessary to preserve the vital state of the rest of the plate, therefore the air temperature of the dryer during this period is raised to 37-38° and, by increasing ventilation, the air humidity is reduced to 65-65. 70%.

This change in the regime increases the selection of moisture from tobacco in order to reduce its content to a minimum by the end of simmering and facilitate the subsequent fixation of the material.

Yellowing, which begins at the top of the leaf, gradually covers the edges and spreads throughout the entire leaf blade. As the sheet turns yellow, the air temperature in the dryer is gradually increased, increasing ventilation. By the time the sheet yellows by one third, the temperature in the dryer is adjusted to 40°, and then to 42-43° with full ventilation. By this time, the top of the leaf begins to curl and dry out. Air humidity during this period should not be higher than 45-50%.

Simmering in a dense mass. Simmering is carried out at a temperature of 32-35°C and a relative air humidity of 80-85% until 2/3 of the leaf blade turns yellow. At this time, the chamber operates with full air recirculation. The duration of this period for technically mature leaves is 36-48 hours, for immature leaves - 60 hours.

After loading tobacco cassettes into the chambers, heating and ventilation devices are turned on, as well as a control panel for the drying process. The parameters of the drying agent (air) are adjusted to the required ones: temperature – up to 34-35°C and relative humidity – up to 86-93%. After reaching the specified parameters, the tobacco simmering phase begins. It is characterized by the fact that the specified temperature and relative air humidity are maintained in the chamber for 6-10 hours.

Over the next 4-6 hours, the temperature is raised to 37-39 ° C, and the relative air humidity is reduced to 76-87%. These parameters of the drying agent are maintained almost until the end of simmering, and only before the end, a three-hour reduction in air humidity to 45-50% is carried out with its further restoration. This ensures intensive removal of excess moisture that has accumulated on the surface of the leaves, and the restoration of humidity in the chamber to its previous size occurs due to its active release from the inner layers of tobacco.

In conclusion, it should be pointed out that with the correct use of one or another method of simmering or by combining them depending on weather conditions, quite satisfactory results can be obtained. But it should be remembered that for successful drying when breaking tobacco, it is necessary to remove only technically mature leaves. In this way, it is possible to achieve uniformity of the material, both on the cord and on the frame. If there is tobacco of different maturity on the carriage, then due to unequal simmering periods there will be a huge variety of colors in any method of simmering and drying. The variegation of the material, remaining until the end of drying, will complicate subsequent processing and cause unnecessary labor costs. In addition, the quality of some of the leaves will deteriorate significantly.

Drying (fixing) tobacco . By the end of simmering, the tobacco leaves acquire the desired color. At this moment, autolytic processes affecting the quality of tobacco raw materials should be stopped. The only way to stop these processes at the right time is to quickly remove moisture. The longer moisture is retained in tobacco, the deeper the processes of change in the internal composition of the tobacco leaf will go, accompanied by a change in the color of the leaf blade from orange-yellow to dark brown tones. Along with the color change, the taste and aroma properties of the product change significantly.

The rate of change in external conditions during the transition from languishing to subsequent drying depends on the humidity and degree of aging of the tobacco. With a correctly selected simmering mode, by the time the second drying phase begins, the leaves usually have time to become exhausted and wither quite well.

Well-cured tobacco has the following external signs: when bent in half, the fabric does not tear, the leaf becomes soft to the touch (less elastic), the vein is flexible from the top to the middle of the leaf, the shoulders and edges of the leaf sag, and in the central part the leaf tissue remains fragile.

If the dried tobacco is not sufficiently dried during drying, it is necessary to provide for a more rapid decrease in air humidity and a slow rise in temperature. When drying normally withered but insufficiently exhausted leaves, the air temperature and humidity should be changed more slowly.

Under conditions of a slow rise in temperature and a decrease in air humidity, the unexhausted areas of the leaf blade languish until they acquire the desired color.

With the solar drying method, there is no artificial heating, and the rate of moisture removal from the material depends entirely on climatic conditions, which in this case become of great importance.

The influence of climatic conditions on the tobacco drying process is well known in tobacco growing practice. In areas with excessive moisture, raw materials of orange-red and red-brown tones are obtained; in areas with a dry climate, as a result of solar drying, a light-colored product is obtained.

In good weather, solar drying of tobacco gives excellent results. The results are brightly colored orange and orange-red tobaccos with high smoking qualities. Drying under such conditions usually ends in 15-17 days. However, when cloudy, rainy weather prevails during drying, the tobacco in the barn is heated, dries slowly and the raw material turns out to be a dull dark color.

As autumn approaches, while harvesting the leaves of the highest quality top leaves, it is not uncommon for a good sunny day to give way to a cold night with heavy fog. Tobacco, which has dried during the day, becomes very humidified at night, since the shed does not protect well from the penetration of moist cold air. As a result of moistening, oxidative processes occur again in the tobacco leaf, which lead to further reddening and browning of the leaf blade. In the end, the leaves lose their original quality characteristics that arose in the first days of drying and are relegated to lower commercial grades.

In this case, drying the leaves in a fire tube dryer gives good results. Additional drying is applicable even in areas that produce typical sun (red tones) raw materials. You should only carry out further drying when the plate has dried and the midrib remains damp, drying which in a barn usually takes a lot of time.

If the farm does not have fire dryers, then the only way to withstand unfavorable external conditions is to maximize the insulation of the sheds at night and in wet weather.

Despite all the shortcomings, the solar method of drying tobacco will persist for a long time in all tobacco growing areas. In addition to the fact that the use of solar heat is most expedient from an economic point of view, solar drying produces raw materials with a specific taste and aroma characteristic of certain types of tobacco.

Of course, these features can be reproduced using the “climatic” drying method, that is, when drying under specially conditioned air in a drying chamber. However, this method requires special structures and the expenditure of a certain amount of energy. Therefore, the importance of solar drying cannot be underestimated.

In the process of chimney-fire drying, the simmering of leaves should in no case be allowed to reach the point where a yellow color appears throughout the entire blade, since a completely yellowed leaf is on the verge of dying and a delay in dehydration will lead to rapid reddening and browning of the tissue (in practice, this phenomenon is called “steaming” of leaves ), which will reduce the grade of raw materials. It is necessary to make a transition from languor to fixation. From the moment the leaf blade turns yellow by one third, the temperature continues to be slowly increased while simultaneously fully ventilating the room.

The leaf, which by this time begins to dry out, turns up the dried top, forming something like a boat. The part of the leaf that retains its green color continues to languish. A slow increase in temperature from 40-42° is carried out in such a way that after 5-6 hours it reaches 45° with a maximum decrease in air humidity (below 40-45%). Such conditions are maintained until most of the leaf plate dries. By this time, the greenery remaining at the midrib and base of the leaf has almost disappeared.

After most of the leaf has dried, the temperature in the dryer is increased to 48-50° and maintained at this level until the entire leaf blade is completely dry. By this time, it remains to dry the midrib of the leaf, which in the lower part (at the base) remains damp for a long time. To speed up the drying of the vein, the air temperature is increased to 60-65° with a minimum air humidity of 30-40%. In dryers of a new design, when drying the petiole and midrib, the temperature can be maintained at a level of up to 80 ° C.

The first two stages of drying the exhausted tobacco are carried out with the dryer fully ventilated, the last stage - with the ventilation closed.

To better retain heat, the ventilation in the dryer is completely closed. At 60-65°, the air humidity in the dryer is so low that the small amount of water that remains in the veins is completely removed with sufficient speed when the ventilation is closed. Drying is considered complete if the midrib along its entire length becomes brittle and breaks when bent with your fingers.

You cannot unload tobacco if leaves with under-dried veins remain on some of the cords. Tobacco on such cords is easily spoiled. If the unloaded batch still contains individual cords of tobacco with raw veins, they should be separated and dried.

The normal tobacco drying process in a fire dryer, including the simmering phase, usually lasts 76-80 hours. Small leaf tobacco dries somewhat faster, in 65-70 hours.

The given fire drying mode is approximate. In each individual case, with a wide variety of raw materials entering the dryer, there may be deviations in the drying mode, both in temperature and humidity. It should be remembered that a prerequisite for rising temperatures is complete ventilation, that is, a maximum reduction in humidity.

When drying tobacco in a dense mass to obtain high-quality light tobacco, the following technology is used.

After the end of the simmering process, the temperature in the chamber is gradually increased over 3-4 hours to 40-45 ° C and at the same time the humidity is reduced to 67-77%. The fixation phase begins. Such parameters are subsequently maintained until the end of the drying process. However, 4-5 hours after the start of drying, the relative air humidity is reduced to 43% with further restoration of its previous value. This is done again 5-7 hours after the first decrease in humidity.

After the fixation phase is completed, drying of the sheet begins. Over the course of 8 hours, the temperature in the chamber is raised to 46-52o C and maintained for 6-8 hours.

The vein and petiole are dried at a temperature of 75-77°C, which is raised gradually over 16-34 hours. Relative air humidity at this time is reduced first to 26-36% within 16-34 hours, then to 14-26% within 24 hours. A short-term decrease in humidity in the chamber ensures rapid removal of moisture from the surface of the leaves, which leads to a reduction in the drying phase and improves the quality of the raw material.

Methods for drying tobacco. The methods of drying tobacco used in different countries are very diverse. Most of them have been developed over many years of practice in certain climatic conditions and are adapted to the varietal characteristics of tobacco. The raw materials obtained as a result of one or another method of drying certain types of tobacco have specific taste and technological characteristics. Thus, different drying methods combined with growing conditions and tobacco variety created different types of raw materials.

Currently, tobacco leaves are dried by convective methods, in which the heat source is either solar energy or burned fuel. As a result, existing drying methods can be combined into the following groups:

1. Tobacco drying without artificial air heating - air-solar drying.

This method includes conventional solar drying of tobacco, which is widespread everywhere, and shadow drying - drying tobacco in a barn (in the shade). Oriental tobacco is usually dried in the sun. The shadow drying method is widespread mainly in cigar tobacco growing areas.

2. Tobacco drying with artificial heating.

This method includes: drying tobacco with an open fire, practiced in the USA for low-quality heavy cigar tobacco; pipe-fire or fire drying, used for oriental tobacco and American long-leaved tobacco; climatic drying, in which, in addition to heating, artificial air humidification is used in the drying room; combined – semi-drying and final drying.

Solar drying of tobacco. This is the most common method of drying tobacco leaves. It is used in Ukraine, in all tobacco-growing areas of the CIS countries and is widespread throughout the world, and is the most ancient. Solar drying of tobacco leaves comes in a wide variety of options. The most primitive drying method, used in some countries for the production of locally consumed tobacco, is when tobacco leaves are laid out in the morning to dry on the surface of the soil, and collected in heaps at night.

A more complex method is to dry tobacco previously strung on a cord. For convenience, cords with tobacco are tied to poles. During the daytime in good weather, the cords are placed outdoors, and at night and in unfavorable weather they are stored in a shed.

The method of drying with separate cords on poles, the so-called drying method on suruks, was previously widely used on the southern coast of Crimea for drying high-quality Dubeks.

The positive side of this drying method is the ability to provide individual care for each cord of tobacco. However, the high labor intensity makes this drying method completely unacceptable even on a relatively small farm; Currently, it is preserved in countries with a very backward farming culture.

Drying tobacco leaves on wooden frames is more economical. 20-25 cords of tobacco are hung on a rectangular frame made of beams, exposed to the sun during the day, and brought into the barn at night and in bad weather. In this case, tobacco is also simmered on frames. To protect tobacco from rapid loss of water, the frames in the barn are installed quite closely and covered with mats. After the languishing is completed, the frames are taken out into the sun.

In a number of tobacco growing areas, leaves strung on cords are hung out to dry in specially constructed dryers called boguns. . These primitive structures look like the skeleton of a gable roof, under which cords with tobacco are hung on slats. To protect the leaves from rain and dew, the boguns are covered on top with film, slate, iron, etc. Under favorable weather conditions, tobacco raw materials can be of fairly good quality.

The most widespread method of solar drying of tobacco in recent years is drying on mobile frames (“cars”). The drying facility for solar drying of tobacco on mobile frames consists of a tobacco production shed, the required number of drying frames and a drying yard on which frames with tobacco are placed for drying. In the morning they are rolled out of the barn into the sun, and at night they are rolled back into the barn. In case of inclement weather, the frames must also be quickly removed under the roof.

Shade drying of tobacco. This method is usually used to dry cigar tobacco, although in some areas of Central Asia it is also used for drying oriental tobacco. Shade drying of cigar tobacco changes due to the fact that it requires longer periods of simmering and drying to obtain its characteristic light and dark brown tones. The fabric of such tobacco becomes thin and elastic, and the raw tobacco has a specific aroma and taste.

In the shadow drying method, cigar tobacco leaves, previously cured, that is, subjected to a short simmer, are strung on short cords (1 m long) and then hung in a barn on a frame system made of poles, where they remain until the end of drying. Typically, drying times are delayed, reaching 30-40 days.

In a number of countries, various methods are used to speed up the drying of tobacco under unfavorable weather conditions. The barns are heated or the air is simply heated using open braziers. When heated, it is possible to improve the drying process and preserve the quality of tobacco.

Pipe fire drying of tobacco. The dependence of the drying production process on climatic factors that cannot be controlled often leads to a deterioration in the quality indicators of raw materials. Increased air humidity during the period of tobacco harvesting and drying, especially in combination with low temperatures in autumn, does not make it possible to obtain raw materials with the color required for cigarette production. Even cigar tobacco, which is usually much darker than cigarette tobacco, is often dried using artificial air heating. Therefore, in the production of cigarette tobacco, drying methods with artificial heating in specially designed dryers began to be used.

Drying tobacco with artificial heating has a number of advantages. The drying time for tobacco with this method is reduced by 3-4 times. The process does not depend on external conditions and is regulated according to specified modes. With this drying method, less dry matter is lost than with solar drying (that is, a greater yield of raw materials is obtained after drying).

Artificial drying produces raw materials of a light yellow color, which has specific smoking properties. Drying tobacco using the fire method can be completed at the moment when the raw material turns yellow, therefore, further changes in the composition are excluded. During solar drying, changes in the composition of leaf tissue continue with greater or lesser intensity and depend on the moisture content. At the same time, along with a change in color, the chemical composition of the leaf changes noticeably, which, in turn, changes its taste and aromatic properties, that is, artificial drying produces skeletal-type raw materials, which are inferior in quality to solar-dried raw materials. In addition, the use of this drying method is significantly limited by the high cost of fuel.

Therefore, despite the advantages of the artificial drying method, its use is limited. In no case can it completely replace solar drying, since each of these methods provides a unique raw material. Solar drying can only be replaced by a special drying method that produces solar-type raw materials. Its description is given below.

Tobacco drying is carried out in special drying facilities - fire tube and steam dryers. They are a closed, if possible heat- and moisture-proof structure, into which frames with tobacco are loaded along specially adapted paths. Air heating in dryers is carried out by a system of flame and steam pipes, colorizers, special air preparers and other systems. Ventilation in the dryer allows you to regulate air humidity.

Selection of a batch of tobacco for artificial drying . The different behavior of tobacco with different ripening patterns, different degrees of maturity and heterogeneous breaking requires careful selection of batches of leaves loaded for drying. Under no circumstances should you dry tobacco of different botanical varieties, different types, and different degrees of maturity in one batch at the same time. Such tobacco undergoes the languishing process differently and interferes with the correct determination and establishment of the languishing regime.

Leaves of different types behave differently during simmering. The leaves of the lower brittle, less material, always fade faster and dry faster than the leaves of the middle and upper tiers. The upper, most dense and material leaves are especially persistent in preserving greenness.

You cannot remove tobacco of different maturity from the field at the same time. This usually happens due to haste in harvesting, when a large number of leaves are removed from the plant at the same time, that is, along with the mature ones, the immature ones are also broken. Moreover, the mass of tobacco contains leaves of varying maturity, which, after stringing them on a cord, give a very variegated material. It is impossible to select an average mode for such material; some of the leaves usually produce defects. Therefore, successful drying requires not only selecting a batch of tobacco in the barn, but also carefully removing leaves from the field. The basic rule is strict observance of cuttings and harvesting of tobacco only in a mature state. In case of uneven development of tobacco in the field, continuous breaking should be strictly avoided; tobacco should be broken selectively, removing only mature leaves.

When selecting a batch of tobacco from the barn for loading into the dryer, it should include leaves of the same breaking period. Tobacco broken at different times will behave differently when languishing. The tobacco that has been in the barn for more than a day manages to lose a certain amount of water and partially goes through the languishing process, as a result of which, by the end of languishing, it will be sharply different from the tobacco loaded with it into the dryer, but at a later stage of breaking. While the condition of the tobacco that has been in the barn will require forced drying, the rest of the mass will still have to languish. This heterogeneity of material will also lead to partial spoilage of some leaves from the loaded batch.

In addition to the above requirements, working with tobacco requires careful handling of the leaves. The delicate leaf tissue is very easily damaged during transportation from the field, unloading, hanging cords on wagons, etc. In all cases, when the leaf tissue is damaged due to careless handling, rapid moisture loss occurs in the damaged areas and the processes are terminated before the yellow color is acquired. Such leaves with damaged tops can often be found in the dryer if there is no struggle for careful handling of the harvest. It is easy to detect damage by running your hand along the tops of the leaves hanging on the cord: damaged leaves have dried ends, while the bulk of the tobacco is still far from drying out. Dried tops of leaves, while retaining their green color, sharply reduce the quality of the material.

Thus, for successful simmering, and, consequently, the entire process of drying tobacco, the following rules must be observed:

– tobacco must be removed from the field in a mature state;

– the batch of loaded tobacco must be uniform in maturity;

– tobacco must be of the same botanical variety and of the same breaking grade;

– it is necessary that the loaded batch includes tobacco of the same withdrawal period (within 24 hours);

– it is necessary to monitor the safety of tobacco leaves, carefully avoiding damage to the tissue.

Drying tobacco in a dense mass . Such drying is carried out under conditions close to generally accepted ones. In this case, only the conditions for the processes are different. The loading density of drying structures with strung tobacco is approximately 1.0-1.5 kg/m3, as a result of which conditions are created for free moisture and heat exchange between the leaves and the surrounding air. In this case, the density of loading tobacco into the chamber is approximately 10 times greater, and heat and moisture exchange during forced convection occurs under difficult conditions of interaction between the material and the surrounding air.

With this drying method, the costs of preparing tobacco for drying are significantly reduced by replacing the stringing of leaves with arranging them on cassettes. However, the quality of the raw material is inferior to the quality of tobacco leaves from other drying methods.

Climate drying of tobacco . In many tobacco-growing areas, sun-type tobacco is produced. Depending on the existing climatic conditions during drying, the appearance and internal advantages of the raw material are formed.

Sun-cured tobacco has bright orange-red and red-brown tones. As indicated, this coloring is due to developing oxidative processes in the killed tissue and the formation of dark-colored products. Indeed, the longer the killed leaf tissue is in moist air, the more the color changes towards the accumulation of orange-red and red-brown pigments. Along with the color change, the composition and smoking properties of the raw material also change. Tobacco acquires a specific taste and aroma.

As a result of the constant action of natural factors in a number of tobacco growing areas in a high humid zone on the Black Sea coast, a type of raw material with a characteristic bright orange-red and red-brown color was formed, which has won worldwide fame for its high quality indicators.

However, in many cases, during prolonged cold and wet weather at this time, too deep changes in the composition of dead tissue deteriorate the quality of the raw material. The leaf is depleted of carbohydrates, a void of taste appears, and the color becomes dark and dull. Most often, in such unfavorable conditions, the leaves of the upper brittle leaves, which ripen in the fall, are dried.

Attempts to eliminate the adverse effects of weather by using accelerated drying in fire tube dryers were unsuccessful. With the rapid removal of moisture, which interrupted the processes of changes in the composition of dead leaf tissue, the resulting raw material was light in color, not typical for this type. The taste and aroma of tobacco was close to neutral.

Based on the fact that the pigments that color the leaf in orange-red tones arise in processes associated with the oxidation of polyphenolic substances, a new drying regime was developed that ensures the development of processes characteristic of sun-type tobacco.

The exhausted and slightly dried tobacco under the drying regime, called “climatic”, was supposed to be provided in the future with a sufficient amount of moisture necessary for the development of oxidative processes. The duration and depth of transformation of the composition in this phase was regulated by the degree of moisture saturation of the air. To humidify the air in the drying chamber, a low-power air conditioner was installed. By adjusting the relative air humidity in the second drying phase (color development phase), it is possible to obtain tobaccos from light orange to dark red tones.

The “climatic” drying mode is as follows. After simmering tobacco, as is usual for the fire method, the relative air humidity in the dryer is reduced to 65-70% by ventilation and raising the temperature to 38-40°. Under these conditions, the exhausted part of the leaf dries out, but, retaining a certain amount of moisture, begins to acquire an orange color. The rest of the record continues to languish. This mode is maintained until the orange-red tones spread to about half the sheet. Then, by increasing the ventilation of the dryer, the humidity is reduced to 60-65% to prevent the sheet tissue from reddening too much. When redness spreads to the entire plate, the temperature is increased to 47-50° with air humidity of about 40%. Under these conditions, the vein is dried. The entire process of “climate” drying takes place within 8-9 days. If it is necessary to obtain tobacco of a darker color (red-brown), the air humidity in the dryer is maintained at a higher level (10% higher). The commodity assessment of climate-dried raw materials is usually high. Analysis of the chemical composition and tasting of tobacco gave results characteristic of this type of sun tobacco.

In a number of tobacco growing areas, in addition to the main drying methods, combined methods called semi-drying and post-drying are widely used.

Half-dried tobacco is as follows. Tobacco, cured in a barn using one of the described methods, is dried in the sun for 3-4 days, and then loaded into a dryer for final drying. If you need to get raw materials with a lemon-yellow color, tobacco cured in a barn is loaded into a dryer without drying in the sun. The color of tobacco leaves is fixed in a fire dryer. The temperature is gradually increased to 42-45° with full ventilation.

Then the process is carried out in the same way as with complete fire drying. Depending on how deeply the processes of changing the composition and color of the tobacco went during its stay in the barn, the resulting product had a light yellow color (close to the usual type of fire-dried raw material) or with orange tints, if the processes of reddening of the fabric had already begun in the barn leaf. This method produces raw materials that are quite satisfactory in color and internal qualities. The main advantage of the method is that if there is a lack of fire dryers, their throughput during semi-drying increases, since it takes only about two days to dry tobacco in a fire pipe dryer without simmering.

Drying tobacco produces a product very close in quality to sun-type tobacco. In this case, tobacco, which has largely dried in the barn, is loaded into the fire dryer. In this case, the fabric receives the color characteristic of sun tobacco of this region; only the leaf veins and a small part of the plate adjacent to the vein are dried in a fire dryer.

This method can be successfully used in areas that produce sun tobacco, especially if wet weather during the drying period lengthens the time it takes for the tobacco to dry in the barn. If it takes about 8-10 days to dry a leaf blade under these conditions, then the midrib, due to its high moisture content, retains a large amount of water for a long time, which does not allow tobacco to be removed, and the dried blade, exposed to humid night air and periodically freezing, becomes very dark. . Tobacco dried in a dryer using the methods of complete fire drying, semi-drying and final drying is more stable during storage and is less susceptible to mold.

The throughput of the dryer increases by 1.5 during semi-drying and twice as much during drying. Fuel consumption per 1 kg of dry tobacco with complete fire drying is up to 1 kg of liquid fuel or 0.5 m3 of natural gas. During semi-drying, fuel consumption is reduced by 25-35% compared to full fire drying, and by 60-70% during final drying. Therefore, semi-drying and post-drying are used in production more widely than full fire drying.

With solar and shade drying of tobacco, fuel costs are eliminated. However, in cool and rainy weather, the dried raw materials do not acquire the required quality, and sometimes even deteriorate. Therefore, every household must have turbo-fire or steam dryers.

With complete fire drying, compared to solar drying, the duration of the tobacco drying process is reduced by 3-4 times. Methods of semi-drying and post-drying also make it possible to reduce the duration of this process. With semi-drying, the drying time for tobacco is reduced by 1.5-2 times compared to solar drying, and with additional drying - by 3-5 days.

Solar and shade drying methods are usually used in the first period of the tobacco harvesting season, when the weather is dry and hot. Fire dryers are used in the second half of the tobacco harvesting season to dry or semi-dry it. The full fire drying method is recommended to be used only in late autumn, when solar heat cannot be effectively used to dry tobacco.

Tobacco drying in a multi-zone continuous installation (CCD). The operating principle of the dryer is based on the movement of shelves with tobacco through chambers (zones) with different, but constant air parameters for each zone. Such continuity of the drying process in the UND creates a certain organization in carrying out technological operations for preparing, loading, simmering, drying and unloading the material.

The UND tobacco drying technology is as follows. Tobacco leaves brought from the field, after a short warming, are secured on a cord by machine and placed on shelves in a vertical position in the form of garlands. Shelves with tobacco are placed in the preparatory department for 10-12 hours, where it is smoked. Then it is moved to the climatic zones of the installation.

In the middle tunnel, the tobacco simmers for 18 hours. After this, it is moved to the side tunnels for drying. Tobacco passes through the zones at certain equal intervals of time, undergoing all stages of the technological process. The installation capacity is 2 tons of dry tobacco per day. However, plant productivity can be increased by compact loading of shelves and by careful selection of homogeneous batches dried in the preparatory department. As a result, after drying in the UND, it is possible to obtain raw materials of high quality, light color, skeletal type (the yield of the first light varieties is 70-80%).

Drying filichs, ashlaks and frozen tobacco. Filichi are leaves grown on the side shoots (stepchildren) of plants (second harvest). The shape of the leaf blade is more pointed, the tissue is less dense, dark green in color. In terms of technological properties, they are close to unripe tobacco. They contain more water, turn yellow poorly when simmered and dry out slowly when dried. Filichi produce a satisfactory quality product only if the tobacco is well cared for in the field.

For better growth and development of shoots, immediately after harvesting the main tobacco crop, the row spaces are treated with cultivators, and after 6-8 days, excess shoots are removed, leaving 1-2 of the best ones. When buds appear on them, the latter are torn off along with the upper, underdeveloped leaves. The harvest is harvested with the onset of technical maturity of the leaves, and if there is a threat of frost, without waiting for maturity.

In dry and warm weather, the shoots are removed and dried as whole plants. Under less favorable conditions, it is advisable to harvest the crop leaf by leaf and dry the leaves in a strung form. The best results are obtained by combined drying methods (half-drying with drying the leaves in the sun and further drying).

In dry years, if harvesting is not done on time, part of the crop becomes overripe and dries out. This type of tobacco is called ashlak. Remove it after it has completely dried on the plant in the morning, when it is wet. The harvested leaves are packed into bales or bales and delivered to collection points. Tobacco damaged by frost (gazelle) is removed when it is completely dry and acquires a brownish-brown color. Processing techniques are the same as for ashlaka.

Drying tobacco with whole plants. Tobacco plants are dried in the shade or in fire-pipe dryers. To do this, they are pinned onto pins driven into slats, tied with twine into garlands, hung on twine or wire, hooked onto the petiole of the second leaf. In this form they are placed in a drying room. The drying process is completed when all the leaves on the plant are completely dry, the stem remains damp. The duration of drying in the shadow method is 20-25 days, in dryers 4-5 days.

Plants for shade drying are removed from areas of early and mid-planting periods no later than September 1st. When dried in dryers, they can be removed later. The stem-dried leaves are separated, sorted and packaged into bales or bales in accordance with the requirements of the current standard.

I ferment tobacco in a modern electric oven.

It has a function for setting the temperature from +50°C. So I set it to the lowest temperature. The fermentation process lasts only 5 to 7 days. At the same time, energy consumption is minimal, since the heaters in the stove are turned on only a few times a day for a short time to maintain the set temperature.

I ferment tobacco only pre-cut. This makes it easier to control its humidity. Doing this with a whole sheet is much more difficult.

So point by point:

1. What equipment do we need? The stove itself or any other space where the temperature can be maintained in the range from +50°C to +60°C (for example, any box with a thermostat and heater). Two to three liter glass jars with hermetically sealed lids. That's all.

2. Completely dry (they crumble when crushed) tobacco leaves are slightly moistened with a spray bottle on both sides. And put them in piles for one day. Cover the tops of the stacks with polyethylene.

3. The next day, we disassemble the stacks and remove the midrib from each leaf. In this case, the humidity of the leaf blade is controlled as follows:

a) The sheet should not be too damp or break at the bend.

b) The surface of the sheet must be dry, but at the same time it must have the appearance and elasticity of a thin rag.

c) If you are not sure that the moisture content of the leaf is suitable for fermentation, then it is better that it is drier than damper.

d) Dry the leaves that are too wet a little, putting them in a pile and stirring occasionally. We moisten the dry ones and keep them in piles under polyethylene.

Why did I write in such detail about what humidity a leaf should have? Because the success of fermentation largely depends on this. You can see what a tobacco leaf looks like prepared for fermentation in my album on Yandex photos link

4) Cut the tobacco into thin strips of 1 - 2 millimeters. Or at the thickness to which you are accustomed to smoking it. I do this using a noodle cutter (you can buy it in online stores). It allows you to cut a large amount of tobacco leaf in a minimum time.

5) Place the chopped tobacco in glass jars, filling them 2/3 full, so that later the tobacco in them can be easily mixed by simply shaking. And screw them tightly with screw caps.

6) Place the jars in stacks in the oven and turn it on at 50°C for five to seven days.

7) Pour the fermented tobacco out of the jars onto a flat surface to dry it a little. When it reaches the humidity you are used to for smoking, place it in any airtight container for storage.

That's what fermentation is all about.

A few important points:

During fermentation, there should be no condensation on the walls of the jars. If there is condensation, then this is the most important sign that you placed the tobacco for fermentation too wet (remove it from the cans and dry it)

On the second or third day of fermentation, the tobacco begins to smell like honey or other fruity aromas - this is a sure sign that fermentation is successful.

The tobacco leaf used for fermentation should have no signs of residual chlorophyll. Chlorophyll is a green pigment that causes the leaves of all plants to turn green.

Green tobacco leaves do not ferment, but rot.

If, however, there are areas with greenery on the leaves, they must be cut out before fermentation. To avoid such areas, the tobacco leaf must be properly cured in a dark, warm room immediately after breaking. And only after languishing, it is hung to dry. Properly cured tobacco loses its green color completely.

What's good about my fermentation method?

Because there is no need to make complex fermentation cabinets with humidity controllers and ventilation.

Because you can ferment small amounts of tobacco right in your apartment.

Because it is the easiest for beginner tobacco growers.

With respect to you, Dmitry Gusev.

It's no secret that the filling of modern cigarettes is more of a pulp and paper mixture with the addition of combustion activators than real tobacco. Therefore, many amateurs practice growing tobacco on their own and making cigarettes on their own.

In addition to choosing the right variety and following agricultural cultivation techniques, to obtain a high-quality smoking mixture you will need to know how to properly dry self-sown tobacco.

How to properly dry tobacco at home

It is best to dry tobacco leaves in a room with low humidity and poor air circulation. Most often, a regular shed is used for this purpose.

It is advisable to dry tobacco leaves at home by stringing them on a cord to ensure the most uniform access of air to all leaves. The duration of the preliminary stage of drying (simmering) tobacco is several days. A sign of proper drying of tobacco leaves is partial yellowing of the leaf blade, no signs of rotting, and preservation of the green color in the main part of the leaf area. After this, you can proceed to the so-called fixation stage, during which the tobacco leaves are completely dried.

On a note

An important requirement for drying tobacco at home is the absence of strong wind in the area where the frames with tobacco leaves are installed, since strong gusts can damage the leaf plate and render the product unusable.

There are several ways to dry smoking tobacco at home. One of the most common options is to dry the tobacco in the sun. To do this, the leaves are strung on cords secured in special frames and placed in a sunlit place.

How long to dry your tobacco will depend on many factors. First of all, weather conditions play a role: air temperature and humidity, the presence and strength of wind, and so on. In addition, the type of tobacco, the characteristics of the soil on which it was grown, and similar conditions have an impact. In most cases, the period for drying tobacco at home is from 20 to 40 days, depending on the factors listed above.

There are also special rooms where you can dry tobacco. In particular, with steam drying, pipes pass through the room in which the leaves are dried, providing high temperature and low humidity. However, the use of such methods is not always suitable. For example, Turkish tobacco can only be dried in the sun.

The next stage is fermentation of the leaves, which consists of the transformation of a number of substances. Contained in tobacco leaves and their acquisition of properties that favorably affect the smell and taste of the resulting smoke.

Regarding the question of whether tobacco leaves can be dried in the oven, clarification will be required. Drying fresh leaves of smoking tobacco using this method is not recommended, since if the moisture evaporates too quickly, the required chemical composition of the leaf will not be provided, which will cause a deterioration in the taste of the smoking mixture being produced.

The oven is usually used to ferment tobacco, the final stage of preparing the leaves of this plant for use as a smoking mixture. To do this, the midrib of the leaves, previously dried in the manner described above, is removed, cut into thin strips and placed in glass jars, filling them two-thirds. The jars are hermetically sealed with lids, placed in the oven and the temperature is set to about 50 degrees for seven days.

The situation regarding whether it is possible to dry tobacco leaves in the microwave is actually similar. The procedure for drying tobacco cannot be carried out using this technique, but if you want to adjust the chemical composition of the leaf and the taste of the smoke, this method can be used. Only in this case the fermentation time is reduced to several minutes. The method of preparing the leaves for fermentation is similar to that used for the oven.

The plant must be properly processed before being used in pipes or cigarettes. Cutting tobacco at home is a simple process, but should not be rushed. Tobacco leaves must go through several stages, each of which requires a certain amount of time.

Drying after harvest

Growing a plant is only half the battle; well-grown tobacco can easily be ruined by improper preparation. The household method of making tobacco with your own hands differs from the industrial method only in production volumes.

Processing tobacco at home is a labor-intensive but very exciting process. First, the leaves must be sorted out, cleaned of foreign objects, insects, and rotten and moldy parts must be thrown away. If the leaves are not heavily contaminated with dust or dirt from the garden bed, you can immediately begin drying. When the tobacco is very dirty, it is first washed with plenty of water.

After the water has drained, you can begin preparing for drying. The semi-finished tobacco product is dried naturally in air. In country houses, they dry in attics or under the ceiling of the cellar, if it is not very damp. In city apartments, a glazed balcony or loggia is suitable for this purpose.

In order to prepare the bundles, you need to take a thick needle and thread, pierce the thickest part of the stalk, forming even bundles. The number of leaves of one bunch depends on the width of the room where the bunch will dry. The finished bundles are hung in rows on a rope. The leaves change color from green to light brown or yellowish after drying.

Fermentation

Dried leaves can be crushed and immediately started smoking, but the raw material prepared in the usual way will be too strong, without aroma, and contain a large amount of nicotine. In addition, the chlorophyll contained will burn and burn your throat. How to reduce the strength of tobacco? For this purpose fermentation is used.

Tobacco at home is fermented with whole leaves immediately after drying or pre-cut. Fermented chopped samosas will be smaller than those fermented with whole leaves. How to make tobacco fermented?

Step-by-step instructions for fermentation at home:

1. Lightly spray the leaves with water from a spray bottle, wrap them in a damp sheet or put the soaked raw materials in a large plastic bag. In this state, the semi-finished product should stand for several hours. The readiness of the leaves is checked by squeezing the fist: it should be tight, not break, and not have excess moisture;
2. The prepared raw materials are placed in glass jars with a tight lid;
3. Place the jar in a pan of water, put it on gas, and bring to a boil;
4. After boiling, reduce heat and simmer covered for 1.5 hours. The initial smell of fermentation will not be very pleasant;
5. The jar needs to be cooked in this way for another 3-4 hours, after this time the process is considered complete: the dried shag can be smoked.

This fermentation method is the fastest, and it is also suitable for curing tobacco, when various natural flavors are placed in the jar: honey, dried fruits, wine or cognac, prunes and other components as desired.

There are other fermentation methods:

During fermentation, high humidity and high temperature must be maintained, after which the chlorophyll from the leaves turns into sugar, and the strength decreases significantly. The tobacco acquires its own aroma and its taste improves.

Leaf cutting

Cutting tobacco does not require special skills. Before this, the fermented foliage must lie under a tobacco press and then be dried again. After pressing, the leaves retain the shape of a bar; it can be stored whole or crushed. Grinding the leaves is the final stage in the preparation of pipe tobacco. You can cut it manually, or you can use special cutting devices. Or you can adapt ordinary kitchen utensils, for example, a noodle cutter, for this process:

Cut tobacco is suitable for smoking in a pipe or cigarette tubes. The longer tobacco is stored, the more aromatic it becomes, because the fermentation process in it does not stop.

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