2 CIRCULAR 435, U. S. DEPARTMENT OF AGRICULTURE 



of which adhere to the gummy surfaces of the tobacco leaves and are 

 shaken off in the various handling processes. There is also some loss 

 due to the breaking off of small pieces of leaf when the tobacco is 

 handled in dry condition. Foreign-matter Joss is negligible in some 

 types but in the lower grades of other types it may average from 2 to 3 

 percent. It is not given separate consideration in the tables on losses 

 but is included in the figures on dirt and sand and moisture losses. 



Under the second factor of loss in weight — reduction in moisture 

 content and chemical change during fermentation — there is the actual 

 loss in moisture which occurs in the handling, redrying, and packing 

 operations and in the sweating or fermentation processes. In some 

 types of tobacco the greatest moisture loss occurs during the pre- 

 liminary redrying and handling operations and in others the greatest 

 loss occurs during the sweating or fermentation period. 



Some types of tobacco are marketed with a moisture content as 

 high as 35 percent but will mold if packed in this condition. This is 

 particularly true of the types grown generally in the Southern States. 

 To avoid molding, the tobacco is removed to a redrying plant soon 

 after sale, where it passed through a redrying machine which con- 

 ditions it for packing, or it is hung in tiers and air-dried. 



Tobacco goes through a sweat each year. The term "sweat" is 

 applied to the natural fermentation process that occurs in the spring 

 and summer. Fermentation and aging eliminate the acrid pun- 

 gency and bite of new tobacco and give it a sweeter, mellower flavor. 



During the fermentation process tobacco undergoes chemical 

 changes similar to those that take place in any closely packed, moist 

 vegetable matter. The temperature rises and certain volatile prod- 

 ucts and convertible solids are thrown off. The tobacco appears to 

 take on additional moisture and becomes soft and pliable. In addition 

 to the chemical losses, there is actually a loss of moisture when the 

 sweating period is finished. 



Under the third factor, there is the loss in weight from the removal 

 of the stems or midribs. The stem or midrib is excluded from most 

 manufactured tobacco products because of its coarse, fibrous, woody, 

 and more or less flavorless nature. In the manufacture of snuff the 

 whole leaf is usually ground, and in some cases more stems are added. 

 In the manufacture of some smoking tobacco the stems are removed, 

 rolled flat under pressure, and cut finely, and a certain percentage is 

 added to the cut leaf. 



The stemming loss varies according to the proportion of the stem 

 removed and according to the type of tobacco. For some tobacco 

 products it is necessary to remove the entire stem, from the tip of the 

 leaf to the butt. For other products, it is necessary to remove only a 

 few inches of the coarser part of the stem nearest the butt of the leaf. 



The variation in loss as to type is due to the relative size or coarse- 

 ness of the stem in proportion to the leaf surface. Stems are removed 

 from some tobacco prior to packing, fermentation, and storage, but 

 the greater part is packed in leaf or unstemmed form and the stems 

 are removed just before the time the tobacco enters the manufac- 

 turing processes. 



RELATION OF PACKING AND STORAGE METHODS TO LOSS IN WEIGHT 



Practically all southern tobacco, or types other than cigar-leaf, is 

 packed in hogsheads for storage and shipment. A limited quantity 



