64 The Fermentation of Cacao 



was furnished by the bacterial growth, or, what 

 is less probable, by the yeast cells. 



The " fermentation " should not take longer 

 in Porto Rico than fifteen to twenty hours, 

 while in some sections of Central America, as 

 Guatemala, it must be carried on for two days j 



Undue prolongation of the fermentation must 

 be avoided, as otherwise a brown colouration 

 of the parchment and of the seeds is produced, 

 and the seeds would further acquire a disagree- 

 able odour two circumstances which render 

 the product unfit for market. 



After the fermentation and washing, the 

 parchment coffee is readily dried, either on 

 cement floors exposed to sun and air, or better 

 in rotating cylinders through which warm air 

 passes. At a certain degree of dryness the 

 parchment becomes brittle and breaks easily 

 in the milling process, which thus removes the 

 parchment envelope and silver skin from the 

 seeds. In fact the milling must be done 

 while the parchment is still warm. 



This milling is in many cases done in 

 London and not in the country where the 

 coffee is produced. Better preservation of 

 the shape and colour of the bean has been 



1 When carrying out these investigations Dr. Loew 

 was Physiologist to the Porto Rico Agricultural Ex- 

 periment Station, and this essay or report was first 

 published in the Annual Report for 1907 of that station, 

 and afterwards reprinted separately, as pamphlet 1093 

 by the U.S. Dept. of Agriculture. 



