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TOBACCO CURING


In the case of tobacco, unlike in other crop plants, the farmer cannot get any return by merely producing the crop of the right type in the field. This has to be followed by successful curing. Curing is the process by which the harvested tobacco leaf is made ready for the market. Curing is essentially a drying process whereby most of the moisture in the harvested leaf is removed. However, this process of drying is conducted in such a way as to produce certain well-defined and desirable qualities in different types of tobacco. A bad leaf produced on field cannot be improved by curing; but a good leaf can be spoiled by bad and defective curing. The process of curing has an intimate bearing on the quality of the final produce. During the progress of curing, some important biochemical changes take place. The curing operations followed in India are dependent on several factors, such as tradition, convenience, market value of the crop, consideration of economic production, etc. Depending on the type of the tobacco, four principal methods of curing can be distinguished, namely, i) flue-curing, ii) air-curing, iii) fire-curing and iv) sun-curing. Though some of the characters that govern quality in tobacco are gene-controlled, a good curing management play a significant role in determining the quality of the commercial leaf. Harvesting, curing, bulking and preliminary pre-sale (farm) grading constitute some of the important aspects of post-harvest technology of tobacco.

FLUE-CURED VIRGINIA TOBACCO

Harvesting the crop:

The aim should be for the production of uniform, well-matured crop and only such ripe leaves should be harvested. Ripe leaves have greenish-yellow colour, have a velvety feel and have lost much of their stickiness. They have a tendency to lie horizontally or bend slightly down the plant and the leaf-tips are slightly dry. As a general rule, the leaves are harvested from the bottom primings slightly on the green side, the middle leaves when they are ripe and the top leaves when they are fully ripe. On an average, not more than three leaves should be harvested at a time. Harvesting must be done on a clear weather day. Immediately after rains or irrigation the crop should not be harvested and it is to be delayed by 2 - 3 days in such cases. Under normal condition, priming is once in a week. The leaves should be pluck against the direction of the sun for better judgment of matured leaf colour. While picking, the midribs should not be bent down, but they have to be bent side-ways. A well-matured leaf will snap crisply with a characteristic sound. The leaves are to be carried carefully without pressing to one end of the field and placed carefully in a wide basket with tips upward. The basket has to be taken to the tying shed as early as possible to minimise wilting in the field.

Green-leaf grading:
In spite of utmost carefulness, on a field scale harvest, it is sure to harvest some immature tobacco. They have to be sorted out before tying. Similarly, over ripe leaves are to be separated if any. These over ripe and under-ripe leaves have to be tied separately so that each stick contains leaves of uniform colour. Over-ripe leaves are usually yellowish-white and under-ripe leaves are relatively dark-green.

Tying the leaves:
The leaves are to be tied to sticks by handling gently in a shaded place avoiding wilting and bruising. A bruised leaf (physically damaged) does not cure well in the barn. About three leaves are tied in a bunch, back-to-back, with a jute twine loop on a stick. About 90-100 such leaves are tied in separate bunches with a series of loops on a stick approximately 130 cm long. The leaves are distributed uniformly all over the length of the stick to avoid over crowding.

Loading the barn:
For a satisfactory curing, the whole barn should be loaded with the freshly harvested leaves from a single priming. The un-ripe leaves (green) are placed on the top tiers, the over-ripe leaves (yellowish-white) leaves on the bottom tier and well-matured leaves (greenish-yellow) in the bulk of the intermediate tiers. The sticks are placed on the tiers approximately at a distance of 20-25 cm so that the leaves from the adjacent sticks slightly touch each other without pressing. A 5m x 5m x 5m barn will usually be loaded with 750 sticks with such spacing. The barn should never be over loaded while curing the bottom and middle leaves since they spoil easily if drying rate is slow. Leaves from the top of the plant may be crowded slightly more by closer spacing without much detriment to grade-return. Loading of the barn should be completed by late afternoon.

Curing practice:
Curing virginia tobacco according to fixed schedule is not possible all the time because of the variability in green leaf due to various factors like weather condition, Plant position, leaf maturity, disease prevalence and in such cases slight adjustment in the procedure is necessary. The schedule will only serve as a broad outline and individual judgement will be necessary in almost every case.

Curing principle:
The early stage of flue-curing should permit continuing biological activity in the leaf permitting destruction of chlorophyll, conversion of starch to simple sugars and leaf proteins to soluble nitrogenous constituents. These cellular reactions take place in fully turgid leaf cells in aqueous medium and for complete enzymatic reactions, thermal inactivation of these enzymes must be prevented. This means maintaining high humidity and low temperature in the barn for these favourable reaction sequences. During this period leaf turns yellow containing high percentages of soluble sugars. Now, further breaking up of sugars by respiratory enzymes have to be prevented since cured leaf must contain high sugars; browning reaction caused by another set of enzymes - polyphenol oxidase - turning the yellow leaf to browns has to be avoided and possibly bio-chemical conversion of soluble nitrogen to ammonia has to be arrested since some of these soluble nitrogenous constituents transform into aroma-bearing constituents at a later stage. These are achieved by thermal desiccation at the subsequent stage of curing by progressively raising the temperature of the barn and lowering relative humidity by ventilation adjustments. However, since all these biological reactions are a sort of continuous process, changing the temperature and humidity of the barn must necessarily be slow and progressive; abrupt change in temperature and humidity should never be made in the barn while curing is in progress.

 

Details of the improved curing method are given below:

1. Yellowing:
                  Temperature - Dry bulb 85-105 o F,
                  Wet bulb 82-94°F.
                  Time - 36-48 hours.

Furnace is charged after loading the leaf and temperature raised by 5 to 6°F above outside temperature. Top ventilator is left very slightly open, especially during the cooler hours of the night, bottom ventilators are left open with slight gaps so that upward movement of air continues in the barn.
Temperature is raised by not more than 1 to 2°F per hour reaching 105°F by the time the leaf becomes yellow and is ready for fixing. Temperature should be raised in such a way that yellowing is nearly completed by the time it reaches 105°F. Top and bottom ventilators are gradually opened to 3 or so.

2. Fixing colour:
                  Temperature - Dry bulb 105-120°F
                  Wet bulb 94-98°F
                  Time 5-10 hours
                  Progressive total time 39-47 hours.

Great care is required in raising the temperature during this stage. It is raised by not more than 1 to 2°F every hour. Bottom ventilators are opened to 3 - 5 at the base. Top ventilator is raised to a height of 3- 5 from the roof. It is not necessary to raise the top ventilator completely.

3. Leaf drying:
                  Temperature - Dry bulb 120 to 145°F
                  Wet bulb 98 to 110°F
                  Time : 36-48 hours

After getting 130°F the top ventilators are gradually closed and later the bottom ventilators are closed. At 140°F all the ventilators are closed.

4. Midrib drying:
                  Temperature - Dry bulb 145 to 160°F
                  Wet bulb 110 to 114°F
                  Time : 24-36 hours
                  Progressive total time: 88 to 101 hours.

Temperature is raised and maintained at a maximum of 160°F until the stem is dry. The ventilators which have been closed during the later part of the leaf-drying stage continue in the closed position.

Unloading the barn:
After the curing is over, the fire is put off. The barn is allowed to cool down keeping the ventilators closed. The leaf has to attain proper condition for handling. For this, all doors and ventilators are wide open at night so that leaf will absorb moisture from the atmosphere and become soft. In dry weather, wet gunny bags are put on the flue pipe with very slow fire in the furnace to build up humidity inside the barn for few hours just enough for leaf handling. The sticks are removed from the barn and kept in the racks. The leaf is untied from the sticks when there is proper condition preferably in early morning hours and bulked.

Bulking the cured leaf:
Bulk must be made with a view to efficient grading. Leaves of different varieties must be bulked separately. Leaves from different stalk position must also be kept separate. When space in the shed permits for separate bulks, this should be done. However when space is limited, leaves may be bulked together with adequate identification marks for each priming (paper markers may be placed in between two primings). The bulk must be about one meter high on a raised platform. The bulk should never be on the floor or near any material likely to give offensive odour like insecticides, fungicides or fertilisers. When leaf is being bulked, a close watch should be kept on moisture condition. Bulking too dry causes shattering of leaf whilst leaf which is over-conditioned, will loose colour, and may become moldy. The correct condition can be judged by handling a bunch of cured leaves and pressing them tight in the fist of the palm and if after release of pressure, the leaves spring back, if it is over-conditioned. If it breaks while squeezing, it is under-conditioned. The bulks have to be covered with polythene sheets (or some other suitable covering e.g., tarpaulin) and weight down sufficiently to compact the bulk without damage to prevent gain or loss of moisture. The bulks are to be examined from time to time. The bulk is turned for approximately 2-3 times prior to grading depending on the moisture content.

Grading:
Grading is the sorting of cured leaves into lots which are, for their manufacturing purpose, homogeneous according to the plant position styles and external appreciation. Factors to be considered include overall colour, blemish, damage, texture, leaf length and ripeness. These will be applied to various degrees, depending on the tobacco type and market requirements, to each plant position style category. In black soils farm grades and in light soils plant position grading is practiced.

Grading is one of the important production practice in flue-cured Virginia tobacco production. The main purpose of farm grades in black soil tobacco and plant position grades for light soil tobacco is to avoid dual grading at farmer's level and trader's level and thus reduce the marketing cost. This helps the growers to realise more income for his produce, saves time for the exporters and renders the fixation of minimum support prices and minimum export prices for each grade more easy.

 

The 10 farm grades and their specifications are given in Table-7

Table-7: Grade specifications for the 10 farm grades for black soil tobacco.

S. No. Grade Color Body Texture Blemesh not to exceed Corres-ponding Agmark grade
 1  Farm-I  Bright lemon or orange  Thin to Medium  Soft  25%  1 to 4
 2  Farm-II  Light Brownish yellow or Brownish lemon  Medium  Good  25% (White to yellow blemish allowed)  LBY 1
 3  Farm-III  Light Brown  Good to Medium  Medium  50%  LBY 2
 4  Farm-IV  Brown  Heavy Body  Medium to Coarse  50%(brown blemish allowed)  Brown
 5  Farm-V  Dark Brown  Heavy Body  Medium to Coarse  50%  Dark Brown
 6  Farm-VI  Light Greenish orange  Good  Soft to Medium  10%  LG
 7  Farm-VII  Light Medium green  Heavy  Medium to Coarse  25%  LMG
 8  Farm-VIII  Medium Green  Heavy  Medium to Coarse  35%  MG
 9  Farm-IX  Dark Green  Coarse  Coarse    DG
 10  Farm-X  Colour may range from orange, yellow green and / or brown  Variable  -  -  Pl & Bits

Note: For accidental errors in grading, a tolerance of 10% of leaf confirming to the next lower grade shall be allowed in grades 1 to 9.

GRADING FOR FLUE-CURED VIRGINIA TOBACCO IN NORTHERN LIGHT SOILS AND KARNATAKA LIGHT SOILS
 

The main features of this grading system were :-

  • Divide the leaves on the plant into four positions viz. Primings (P), Lugs and Cutters (X), Leaf (L) and Tips (T).
  • In each plant position, leaf will be segregated into different grades based on the quality and colour factors.
  • For the purpose of green colour grades, the plant is divided into two positions Bottom (P & X) and Top (L & T).
  • To accommodate PL, Scrap, bits etc., a grade called No Grade (NOG) was provided.

The plant position grading at the farm level to Northern light soil and Karnataka light soil tobacco and the specifications for the 63 grades are given in Table-8 and 9.

Table 8: Grade Designation and definition of quality of unmanufactured flue cured virginia tobacco grown in Northern Light Soils of Andhra Pradesh and Karnataka state (plant position).

Group(plant position) Grade colour Spot / blemish / injury / waste in terms of percentage Maturity / grain / texture Body Description of leaf
 Primings(p)  P 1 Bright lemon or orange
P 2 lemon or orange
P 3 lemon or orange
P 4 lemon or orange
P 5 lemon or orange
 Up to 20%


20 to 30%

30 to 55%


Up to 80%


more than 80%
 More ripe & Grainy

-do-

-do-

-do-


-do-
 very thin

-do-

-do-

-do-

-do-
 Being sand leaf shows a material amout of injury and subject to disease to a large extent compared to other groups. Comparitively short leaf having open face and an earthy nose
 Lugs and Cutters(x)  X 1 Bright lemon or orange
X 2 lemon or orange
X 3 lemon or orange
X 4 lemon or orange
X 5 lemon or orange
 Up to 20%


20 to 30%

30 to 55%

Up to 80%

more than 80%
 ripe & very grainy
-do-
-do-
-do-
-do-
 thin to medium
-do-
-do-
-do-
-do-
 Comparatively broader leaves with wider spread from butt end. Elastic fine texture with natural luster, charecterized by small midribs and veins
 Leaf(L)  L 1 Bright lemon or orange
L 2 lemon or orange
L 3 lemon or orange
L 4 lemon or orange
L 5 lemon / orange
or Mahogany
 Up to 20%


20 to 30%

30 to 55%

Up to 80%

more than 80%
ripe to medium grain

-do-

-do-

-do-

-do-
 medium to heavy
-do-
-do-
-do-
-do-
 Usually long, but not as broad as cutters, Gummy but not very elastic. Generally having pronounced midrib and veins. They tend to fold along the midrib.
 Tips(T)  T 2 Lemon or Orange
T 3 Lemon or Orange
T 4 Orange or Mahogany
T 5 orange or Mahogany
 Up to 30% 30 to 55% Up to 80% more than 80%  Under ripe Medium to close grained -do-  Medium to heavy  Pointed tips with narrow blade coarse texture having deep colour intensity. Leaf having prominent midribs and veins.
 "P" & "X" BG(Bottom Green)  Bright yellow or Lemon or Orange to light brownish yellow or orange or lemon with greenish tinge.  Up to 25%  Ripe, Grainy, Fine to Medium  Light to Medium  Nil
 "L" &"T" TG(Top Green)  Deep yellow or Lemon or orange to light brownish yellow with greenish tinge  Up to 25%  Ripe to under ripe, less grainy, medium to coarse  Medium to heavy  Nil
 "P" & "X" BMG(Bottom Medium Green)  Bright yellow or lemon or orange to light brownish yellow or orange or lemon with green cast on  Up to 50%  Ripe, grainy, fine to medium  Medium  Nil
 "L" & "T" TMG  Deep lemon yellow or orange to light brownish yellow with green cast on  -do-  Ripe to under ripe, less grainy to close grained, medium to coarse  Medium to heavy  Nil
 "L" & "T" "P" & "X" NOG (no grade)  -  -  -  -  Leaf or part of the leafe(except stems) including pershed and trashy leaf, scrap and bits from all positions not falling into any of the above grades.

Table 9. List of grades in plant position grading system being followed in Northern light soil and Karnataka light soil areas.

Grade
Priming(P) Lugs & Cutters(X) Leaf(L) Tips(T)
 P 1 L P 1 0 P 1 J  X 1 L X 1 0 X 1 J  L 1 L L 1 0 L 1 J  
 P 2 L P 2 0 P 2 J  X 2 L X 2 0 X 2 J  L 2 L L 2 0 L 2 J  T 2 L T 2 0 T 2 J
 P 3 L P 3 0 P 3 J  X 3 L X 3 0 X 3 J  L 3 L L 3 0 L 3 J  T 3 L T 3 0 T 3 J
 P 4 L P 4 0 P 4 J  X 4 L X 4 0 X 4 J  L 4 L L 4 0 L 4 J  T 4 0 T 4 J
 P 5 L P 5 0 P 5 J  X 5 L X 5 0 X 5 J  L 5 L L 5 0 L 5 J  T 5 0 T 5 J
 BG  NDB  TG  T 4 R
 BMG  NDD  TMG  T 5 R
   NoG    

Where P, X, L & T are plant positions
1, 2, 3, 4, 5 are quality nos. based on the spots and blemish on the leaves.
L: Lemon colour; O: Orange colour; R: Mahogany/Red colour
G: Green colour; J: J- style indicating immature tobacco
BG: The leaf from P & X positions and spot less than 20%
TG: The leaf from L & T positions and spot less than 20%
BMG: The leaf from P & X positions and spot more than 20%
TMG: The leaf from L & T positions and spot more than 20%
NDB: The leaf bits with good colour and without midrib
NDD: The leaf bits without good colour and without midrib
NoG: The leaf which does not fall into any grade.

AIR CURING
Various indigenous tobaccos are put into air-curing. Most prominent among them; Wrapper tobacco of West Bengal, Lanka tobacco and Burley tobacco grown in Andhra Pradesh. The process is rather slow. Takes 6-8 weeks. Results in dark brown coloured tobacco, very lean in sugars and rich in nitrogenous constituents.

BURLEY TOBACCO
The harvesting of burley tobacco is done in the same way as that of flue cured tobacco i.e. by priming method but the leaves are strung with an agave fibre threads at the rate of 100 leaves per 150 cm long twine in a back to back and face to face fashion. The cured leaf strings are hung in racks of a curing shed (having no side walls at 20 cm apart. Burley tobacco cures more favourably when temperature ranges between 16°C - 32°C and relative humidity 70% -75% over a period of 24 days.

Soon after the midribs are dry, the cured leaves are bulked on raised platform keeping 8-10 cm air gap underneath. The bulks should not be higher than one meter. The bulks are covered with tarpaulin, old blanket or preferably paper. Avoid alkathene cover if the moisture condition of tobacco is slightly on the higher side. The bulks are turned frequently depending on the moisture condition like flue-cured tobacco.

Pre sale grading
Like flue-cured tobacco, burley leaf properties change according to stalk position. Leaves from different primings have different uses. All are not equally good for the manufacture of cigarettes. Hence burley needs final grading according to plant position into the following five grades.

WBF - Flyings (First priming leaves)

WBB - Bottom leaves

WBM - Middle leaves

WBT - Top leaves

ND - Non descriptive

Lanka tobacco

Harvesting:

The crop gets ready for harvest 90-100 days after planting. Harvesting in the evening hours by cutting the plants close to the ground when the tips of leaves begin to dry and show considerable thickening and puckering. The plants are left over night in the field to wilt. The plants are brought nearer to curing-shed in the early hours of next day and then the leaves are separated along with a big slice of the stem. The 10-15 wilted leaves are stitched to the agave fibre with the help of tobacco needle (a long iron needle). These are called Thoranam' or Chekka'.

Shade curing:

These Thoranams' or Chekkas' (bunches) are to be arranged on coir ropes and the ropes are to be tied to bamboo racks for a period of 45 to 60 days in a curing shed of the size 48' x 5.5' x 2.5'.

Pit Curing

Bundles of (Thoranams) shade-cured leaves are pit cured in the pits of 8 feet diameter and 3 feet depth by keeping them in circular layers upto half of the pit and then covered by palmyrah leaves and soil, made it air tight. After 24 hours, the leaf (Thoranams) has to be transferred to another pit of the same dimensions, filled and covered in the same way as the first one and kept for 48 hours. Later, the leaf (Thoranams) is to be transferred to the 1st pit in the same way and kept for 24 hours. This transferring process is to be done at nights crescent moon light to avoid loss of moisture.

Bulking:

The leaf is then brought to a shed and bulked. The bulks are to be turned on alternate days till the leaves develop dark brown colour and pungent odour.

Grading:

1. Kotaku: Top two well developed leaves of the plant

2. Baraku: Next two well developed leaves

3. Mattasam: The next two or three middle leaves

4. Gulla or Tepa: Lower leaves, poor in body and size.

Lanka tobacco has an excellent aroma and physical characteristics suitable for manufacture of high quality cheroots.

Cigar Wrapper tobacco

Harvesting and curing

Wrapper tobacco takes about 120-140 days from the date of planting till it gets ready for final harvest. Matured leaves of yellowish-green colour, with light brown spots (spangles) are harvested by priming (Removing 4 or 5 leaves at each priming in four or five installments). Cigar wrapper is an air-cured tobacco. Harvested leaves are placed in katcha curing barn, on racks made of bamboos after stringing the leaves with the help of sutli. The leaves are cured under atmospheric temperature and 70 - 80% relative humidity. The process takes 5-6 weeks for completion.

Air-curing consists of two stages. During first stage, leaf remains alive. To secure a satisfactory cure, the leaf should remain alive till the necessary changes takes place. The harvested leaf is rich in starch. One of the important changes during curing is the disappearance of starch. If the leaf is killed too rapidly by drying, starch is not removed and tobacco is degraded, the green colour changes to colourless and the yellow colour appears. The yellow colour marks the end of the first stage. One of the most important changes during the second stage of curing is the development of brown colour which is due to oxidation and does not take place till the leaf cells are dead. The two essentials for the development of brown colour are oxygen and moisture. Brown colour development is completed in fermentation.

After leaf is dry, it is allowed to come to proper condition for handling. Then, it is tied into hands and bulked on a raised platform. The bulks are broken frequently, hands shaken and the bulks are remade. This frequent shaking and rebuilding of the bulks is necessary to replace any ammonia and carbon monoxide formed during bulking by atmospheric oxygen and excessive rise in temperature.

Grading :

The desirable quality characteristics in wrapper tobacco are uniform light brown colour, thin to medium and pliable texture, smooth and glossy appearance, thin veins and good leaf length.

The cured wrapper tobacco can be classified into 4 grades.

1st grade : Light brown coloured leaves, fine in texture with smooth and glossy appearance and with a leaf length of 40 cm (16) or above

2nd grade: Light brown coloured leaves good in texture with glossy appearance and length 30 cm to 40 cm (12 to 16)

3rd grade: Light brown coloured leaves, medium in texture and length 22 cm to 30 cm (9 to 12)

4th grade: Light brown to dark brown coloured leaves, medium in texture and length below 22cm (less than 9). Also torn and slightly damaged leaves of above three grades are classified as fourth grade.

Sun-curing

In India, a number of tobaccos are Sun-cured. In this method construction of costly structures are avoided. The process is relatively quick (2-3 weeks) and there is little interference from weather changes. There are many modifications of Sun-curing.

a. Curing whole plant on racks: Cigar and chewing tobaccos of Tamil Nadu.

b. Curing leaves together with pieces of stalk on racks: Natu tobacco in Andhra Pradesh.

c. Curing whole plant on the ground: Bidi tobacco of Gujarat, Hookah and chewing tobacco in Bihar.

d. Curing primed leaves on the ground: As chewing tobaccos in Uttar Pradesh and Hookah tobacco in West Bengal.

CHEWING AND HOOKAH TOBACCO IN BIHAR

Harvesting and curing

Crop is harvested at full maturity stage by stack cut method with the help of a sickle or khurpi close to the ground level. After harvesting crop is left in the field for sun-drying for 4 to 6 days. After 2-3 days drying, plants are turned upside down for drying of remaining portion. After 5-6 days of sun drying harvested crop is brought to the curing yard i.e. clean grassy patch and after two days of drying it is turned upside down in the morning. As such it is left for drying for four days, then bigger size heaps (bulk) are formed. After four days heap or bulk is broken (dismantled) and stalk with leaves are spread on grass patch where it is allowed to dry as such for four days and then it is turned and allowed to dry for two days. This process of heaping, spreading and drying, turning and reheaping/bulking and exposing to dew in the night continues for about one and a half month till leaves become dark brown, stalks dry up and loose green colour.

After separation of leaves from the stalk, bundles of 25 to 50 leaves each are formed by tying it with the help of banana fibre. If stalk bits attached to the leaves are not dried up, the bundles should be kept in the sun for 3-4 days for complete drying, otherwise it can be directly kept in the shed. Bundles of the leaves should be arranged into a heap or bulk. This bulking and rebulking should be done 3-4 times at a week interval depending on the moisture condition in leaves and heat generation in the bulk/heap.

Watering and fermentation is most important stage in curing process, because excess watering may spoil the colour and aroma of the leaf and less watering may depress the formation of white encrustation (deposition of sulphate and chlorides of Na, K, Mg, Ca etc.) on the leaf surface. Sunny weather with dry winds or westerly winds are most suitable for watering purpose because even little more watering also will not cause any harm. However, watering and fermentation process should be handled by experienced person or master curer only in order to ensure good fermentation and preparation of high quality leaf.

Grading

After completion of watering and fermentation leaves are graded according to their size, thickness colour & aroma.

1st grade: It is locally called Moorhan or Jotia. It consists of long, broad, thick and dark brown leaves with pungent taste and pleasant aroma.

2nd grade: It is locally called male moorhan. It consists of medium size leaves, less pungent than first grade and brownish in colour.

3rd grade: It is locally called Chhobuva or Chhootki. It consists of brown and small leaves with low pungency.

4th grade: It is locally called Kharsan and it consists of sand leaves of very light weight and inferior quality.

Before packing small bundles of 10 leaves each are made grade wise and two to four bundles are tied together.

Packing

Bales (packing) of 1.5 to 2.0 quintals are made with the help of thatch grass gunny bags or hessian cloth and jute rope. Before packing some water is sprinkled on the leaf bundles to maintain lustre and aroma and to protect the leaves against storage beetle. Bale packings are opened after 10-20 days and repacked. This packing may be opened again after 1 or 2 months according to condition of the leaves and repacked. This process is continued till disposal of the leaf.

CIGAR FILLER TOBACCO

Harvesting and curing

Cigar filler tobacco is harvested by priming the leaves, 4-5 at a time when leaves are mature. The cigar filler tobacco in North Bengal is a sun-cured tobacco. The harvested leaves are strung on a jute string which is then spread on a bamboo stick. These sticks are then transferred to multi-tier bamboo structures, constructed in the open space where sufficient sunlight is available for drying of leaves. After drying the leaves for 7 to 10 days, the leaves are then placed in katcha curing barn till the leaves get completely dried including midrib. On completion of curing which takes 15-20 days, the leaves are allowed to come to proper condition for handling. Then they are tied into hands and bulked on a raised platform. The bulks are broken frequently, the hands shaken and the bulks rebuilt. After bulking for about 6-8 weeks, the tobacco becomes ready for marketing.

Grading

Cigar filler is graded on the basis of leaf size, colour, texture, strength, burn and flavour. It may be classified into the following two grades.

Raasi grade: Leaves with uniform brown colour, thin to medium texture, good size, mild strength, good burning with white ash and agreeable flavour.

Cruz grade: The leaves of smaller size, brown to dark brown colour, medium texture, medium burning with whitish-grey ash and medium flavour.

Jati and Motihari tobaccos

Harvesting and curing

Jati tobacco will be ready for harvest in about 120-130 days after planting or 50-60 days after topping. Matured leaves with yellowish-green colour and brown spots (spangles) are harvested in 2 or 3 installments by removing 2 or 3 leaves at each priming. The Jati and Motihari tobacco grown in North Bengal are cured first in sun and then in air. The primed leaves are left in the field for about 8 to 10 hours for wilting under sunlight. The wilted leaves tied into bunches of 5 to 6 leaves and cured on bamboo splinters in curing sheds for 4 to 6 weeks by which time midribs are dried. Then they are arranged in bulk and fermented. After bulking, the tobacco is graded for marketing. The quality characters desirable in Jati tobacco are reddish brown to brownish yellow coloured leaves with good puckering, good size and glossy appearance.

Grades

The following grades are prevalent in Jati tobacco.

Pan patta : Leaves reddish brown to brownish yellow in colour with good puckering and of uniformly good size and fine and pliable, good body and free from blemishes.

No.1 (Good quality): Good body leaves, satisfactory in colour and puckering, free from blemishes, medium size with minor physical injuries are also included.

Niras (Khunda): Leaves with slightly dark appearance and devoid of puckering with dry feel. Considerable physical injuries blemishes not more than 10% of the total area.

Zal-patta (Fired leaves): Leaves that do not mature properly and are partly burnt before harvest. Blemishes all together not exceeding 25% of the total area and dark coloured.

HDBRG Tobacco

Harvesting

The matured leaves show good body, puckering, slightly yellowish mottling with lustre. The crop is harvested in three phases, i.e., bottom, middle and top leaves. The bottom leaves are light in colour poorly developed with low body. The middle leaves are well spread, lengthy, broad and heavy bodied, contributing a major chunk to the total leaf production, and represents good colour, aroma and texture after curing. The top leaves are sturdy, thick, woody, dark green to medium green and gives dark tan colouration after

Curing and Bulking

Two hundred to two hundred and fifty harvested leaves are stitched with bengal twine with the help of iron needles and allowed to sun cure on pre erected bamboo poles for about 30-35 days. Well cured leaves are characterised by good texture, lustre and pliability. The untwined leaves are bulked for about 30-35 days at 6-8 days interval with 3-5 turnings. Bulking should be done priming wise only to get good quality leaf and profitable price.

Grading

HDBRG tobacco is graded priming wise only as bottom, middle and top leaf. Under each category, two types of grades are given i.e.,

WBR: Bright tan coloured with less blemish, good body and fully matured lengthy leaves.

WBL: Lower short leaves with buff colouration, weak body, moderately blemish and fairly shattery.

Natu tobacco

Maturity and Harvest

The matured leaves show good body, puckering, slightly yellowish mottling with lustre. The crop is harvested in three phases, i.e., bottom, middle and top leaves. The bottom leaves are light in colour, poorly developed with low body. The middle leaves are well spread, lengthy, broad and heavy bodied, contributing a major chunk to the total leaf production, and represents good colour, aroma and texture after curing. The top leaves are sturdy, thick, woody dark green to medium green and gives dark tan colouration after curing.

Curing and bulking

Two hundred to two hundred fifty harvested leaves are stitched with bengal twine with the help of iron needles and allowed to sun cure on pre-erected bamboo poles for about 30-35 days. Well cured leaves are characterised by good texture, lustre and pliability. The untwined leaves are bulked for about 30-35 days with 3-5 turnings at 6-8 days interval. Bulking should be done priming wise only to get good quality leaf and profitable price. Some varieties of irrigated natu tobacco are harvested by stalk-cut method and the stalks are hung on the pre-erected bamboo poles. The leaves are removed from the stalk after bulking.

Grading

Grading is done representing bright (CBT), brown (CBR), dark brown (CDK), green (CG) and perished leaf (CP). The Eluru toranam leaf is graded as ‘Melmi’ i.e good bodied and matured leaf while ‘Gulla’ is bottom damaged leaf without body.

Fire-curing: (Smoke curing)

Important type of tobacco that is fire-cured is Jaffna tobacco of Ceylon and Tamil Nadu used for chewing purpose. The leaf is harvested by either priming or stalk-cutting each leaf together with a portion of the stem.

The leaves are wilted for four hours in the field, tied into bundles and hung of laths in smoke huts. They are then smoked for 12 hours by burning coconut husks, leaf stalks and palmyrah nuts, stacked for 3 days and again smoked. Alteration of firing and stacking at an interval of few days helps in making the colour of leaf even. During smoke treatment the creosotic substances are deposited on leaf surface which gives it a peculiar taste. After smoking the leaves are bulked for 3-4 weeks and than given salt water/jaggery treatment prior to sale.

BIDI TOBACCO

HARVESTING AND CURING

Harvesting of bidi tobacco normally commences in January-February in Gujarat and December-January in Karnataka and Maharashtra. Harvesting of bidi tobacco is done at an advanced stage of maturity. The maturity is judged by pronounced development of brown spots called ‘spangles’. The leaves are ripe for harvest about 75 days after topping. Bright sunny days are ideal for harvesting. Prevalence of cloudy weather affects the quality adversely. Generally bidi tobacco is harvested in Gujarat in the following three ways:

i) Whole plant harvest: The mature plants are cut at the base and left in the field inverted for about three days. The drying is considered when the lamina close to the lower half of the midrib becomes brittle.

ii) Leaf-wise-harvest: Mature leaves exhibiting full spangle development are plucked and left in the field with the upper surface facing the ground for drying. The dried leaves are collected in a tarpaulin and the lamina (bhuka) are stripped off from the midribs. After about 4 days pieces of lamina and veins adhering to the midribs are separated and kept in a separate heap. The midribs are exposed to the sun further for about a fortnight for drying. The bark of the stalks are scrapped with a sickle, dried well and then mixed with the midribs. This mixture is locally known as lakhada. The bottom 2 or 3 leaves called gabia are also collected and dried and heaped separately.

iii) Gugro method: This method is practiced in seasons of deficient rainfall when the leaves do not mature well and there is drying of the leaf along with the midrib. The green lamina of the mature leaf of the standing crop is stripped from the midrib by passing the thumb and the index finger from the base to the top of the midrib. The lamina pieces are spread on the ground for sun drying with the top side facing the ground. Later the stalks are cut and the midribs are separated out from the plants.

In Karnataka and Maharashtra harvesting of bidi tobacco is done by stalk cut method. The whole plants are cut and kept inverted in the field for 6-7 days for sun curing. When dry, the lamina is separated out from the main stem. The midribs are further dried to remove the remaining portion of the lamina. This is Angad tobacco sold in the market.

GRADING

At grower’s level there is no standard system of grading of bidi tobacco. Grades vary according to merchants, manufacturers and also from place to place. Bidi tobacco is valued on the basis of (1) its physical characteristics viz. colour, thickness, size, spangling of the leaf, granulation, brightness or lustre (2) its smoking qualities viz. strength, sweetness and aroma and (3) its burning qualities viz. consistency in burning, ash colour, etc. The purchasers prefer tobacco to be mild in strength and sweet in flavour; it should not leave any after effects in the mouth. Parrot green colour is most sought after. Green, golden yellow and red are also recognised. In texture, the purchasers look for granular texture-fairly thick but not coarse. Spangling is another attribute of quality. In Nipani area of Karnataka, brownish red tobacco with a greenish cast is sought after. Though there is no systematic grading method prevalent in the country, there is, however, some sort of mixing and blending of different types for the preparation of bid patti (flakes).

In Gujarat, bidi tobacco is sorted out into the following four grades as per commercial requirements:

Bukha: This represents the pure lamina portion only. It forms about 55-60 per cent of the produce.

Second grade: This represents a mixture of lamina pieces and veins which are separated after second drying of the midribs or the plants.

Galia or Sand leaves: These are the bottom leaves of the plant. They form about 10-15 per cent of the total produce.

Lakada or midribs: This forms about 17-20 per cent of the produce. Bulk of the produce is sold by the farmers in the form of broken leaf i.e. as Bukha.
In Karnataka at the primary level bidi tobacco is graded in terms of I sort, II sort etc. on the basis of the physical characteristics like leaf colour, lustre, thickness, spangling and smoking qualities like strength, aroma etc. Before manufacture, bidi tobacco is processed and processing is done in two stages
(i) Angad into Jarda and (ii) Jarda into Jardi.

In Maharashtra, generally the tobacco is graded at the primary level into grades I, II, III and IV. Thick leaves with golden yellow or parrot green colour with copious spangle development and capable of giving a strong aromatic smoke are classified as Grade I, Brown, red and blackish leaves are graded as Grades II, III and IV. Other quality characteristics will also be progressively less in these grades.