FACTORS AFFECTING FERMENTING PERIODS 129 



These characters vary in the different varieties which 

 produce white beans as well as those which produce 

 purple beans ; and may even vary in the same variety 

 cultivated in different countries. It is therefore impos- 

 sible to state definitely what is the proper period of time 

 to ferment the beans of any one variety, especially as 

 fermentative activity is largely influenced by climatic 

 conditions, the stage of development of the beans under 

 treatment, the quantity of beans in the bulk, and the 

 aeration of the bulk. 



During hot, moist weather fermentation proceeds far 

 more rapidly than during dry, cool weather. Beans 

 which would be fully fermented in four days under the 

 former conditions would probably take six days under 

 the latter conditions. Immature beans take longer to 

 ferment than mature beans, while over-ripe beans, which 

 have already been subjected to mild fermentation in the 

 fruit-shells, obviously do not require so much further 

 fermentation as the properly matured beans. 



If unduly large quantities of beans are bulked for 

 fermentation without proper provision for aeration, it 

 is invariably found that fermentation is not uniform 

 throughout the mass. The organisms responsible for 

 fermentation require air to enable them to perform their 

 work, and if this is withheld decomposition is more likely 

 to set in than fermentation. 



In the various experiments conducted by the writer, it 

 was observed that a layer of beans about 2 ft. deep gave 

 satisfactory results if the beans were placed in receptacles 

 made of suitable material, perforated on all sides with 

 air holes, and lightly covered with sacking or some similar 

 material which is not impervious to air. 



Fermenting-Chambers. Strong, durable wood is well 

 adapted for the manufacture of fermenting-chambers, but 

 it should be fastened together in such a manner that the 

 iron nails or screws used for this purpose do not come 

 in contact with the beans. The liquid matters which 

 exude from fermenting cocoa beans act upon the metal 

 and discolour the beans. The floor of the chamber 

 should be either well supplied with holes or should slant 

 towards an opening to facilitate the draining away of 

 the liquor given off during fermentation, and the floor of 

 the chamber should be raised above the ground on wooden 

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