TOBACCO. 201 



AiR-CuRiNG. — This method of curing is more generally 

 used than any other, and the greater part of the tobacco pro- 

 duced in the world is air-cured. It is also the easiest and 

 simplest method which can be employed, as the usual practice 

 is to place the tobacco in the curing barn, where it remains 

 until thoroughly cured and ready for preparation for market. 



Air-curing may be described as a natural process of curing, 

 as the tobacco is merely harvested, placed in the barns, and 

 allowed to cure by natural atmospheric conditions. If the 

 weather conditions are ideal good results are obtained, but if 

 wet weather prevails severe losses may result from " pole 

 sweat." On the other hand, should excessively dry, hot, 

 windy weather occur immediately after harvesting, the leaf 

 may be killed prematurely, which greatly reduces the value of 

 the tobacco. In recent years air-curing has, in certain 

 tobacco producing areas, been modified by the use of artificial 

 heat and moisture, which enables the growers to regulate 

 curing conditions and thus to prevent loss after the crop is 

 harvested. 



The conditions most suitable for air-curing are clear, calm 

 days, moderately dry atmosphere, and a temperature of 80° 

 to 90° F. in the shade. Under these conditions the moisture 

 is absorbed by the atmosphere as fast as it is given off from 

 the leaf, and very little oxidation takes place, excepting in 

 wet weather, so that the leaf cures moderately bright in 

 colour. 



Normally, all tobacco should take on a yellow colour be- 

 fore it begins to dry. If the tobacco dries out before the 

 yellow colour appears the leaf will remain green and be of 

 very little value. If drying is delayed after the yellow colour 

 appears, oxidation takes place, and the colour will change to 

 red or brown. The purpose for which the tobacco is to be 

 used largely determines the proper colour of the cured leaf. 

 For cigarette purposes the leaf should be lemon-yellow in 

 colour; for cigars, the most desirable colours are shades o.f 

 brown and olive ; for chewing purposes and pipe mixtures a 

 light red colour is most desired. The conditions of curing, 

 then, should be regulated to produce tobacco most suitable 

 for local market requirements. The time required for air- 

 curing varies from six weeks to three months, depending 

 primarily on weather conditions, but also on the size of the 

 tobacco being handled. 



