96 HULLING AND PEELING. 



cylinders into which steam enters and agitators arranged 

 so that the coffee is impelled forwards and caught up and 

 rained down as the cylinder revolves. The central cylin- 

 der works in a steam packet, outside which is a light 

 casing of sheet iron, perforated at one end so that the 

 air may be drawn through by a fan to assist in the drying 

 and carry off the liberated moisture ; this machine 

 obviates the necessity for respreading the coffee in the 

 terraces before hulling. Three days* thorough sunning 

 usually suffices to render the coffee quite dry and brittle, 

 in which condition it is known as "parchment coffee," in 

 which state, in many countries, it is sent to port, its 

 further curing being left to the shippers, for not only is 

 considerable expenditure in buildings and machinery 

 necessary for the purpose, but the experience gained by 

 manipulating various lots of coffee will enable those 

 who make the subject a special study to bring the sample 

 up to the best standard of appearance and keeping prop- 

 erties, but the coffee retains its color better if allowed to 

 remain for several weeks in the parchment, and its quality 

 continues to improve for months, even years, the pro- 

 cess being known as ** curing;" as, however, protracted 

 curing causes great subsequent difficulty in removing, 

 the " silver-skin " coffee is never kept in the parchment 

 longer than is compulsory. 



This operation consists in the removal of the "parch- 

 ment " and the " silver-skin," after which the beans are 

 again exposed to the sun for a period which is difficult 

 to define. Some planters say that they should be dried 

 till they resist pressure of the thumb-nail, but there is 

 really no infallible test, as no two samples are exactly 

 alike. It needs much experience to prevent loss of weight 



