8. The Processing of Coffee Cherry

     Do you wander how coffee cherry, red, like cherry, a ripe fruit of coffee tree, become coffee beans?

Inside the coffee cherry, there are two stones, called green coffee beans. After peeling off the coffee cherry, we can get the seed of it. However, it's hard to peel using machine because of the thick layer containing pectin,果膠. After putting coffee cherry into water to distinguish bad coffee cherry, floating one,we usually adopt three ways to get rid of it, wet process, dry process and honey process.  

In wet process, bacillus,乳酸菌, and yeast,酵母菌, and some enzyme, 酵素, in the coffee beans decompose the pectin, pectin deriving lactic acid乳酸, alcohol, ketone 酮類, further deriving to acetic acid醋酸, which gives bad smell.  So the time is important in each process of coffee lol. After fermenting, the coffee beans is washed, dried. 

In dry process, the coffee cherry is put in the sunshine two weeks, pectin decomposing, most important, different to the wet process, glutamic acid decomposing into Aminobutyric acid 氨基丁酸, not apple acid.  Unlike apple acid, aminobutyric acid isn't that sour. The research pointed out there are more glucose and fructose果糖 in dry process.  

In honey process, the coffee cherry is peeled, placed in the sunshine two weeks.  Though I cannot tell why it differs from dry process, coffee have honey and fruity aroma without strong, bad smell.  My experience of honey processed coffee is wonderful!!!!!  #edited at 6:34 am ( I couldn't resist to type after having a cup of honey processed coffee.) 

reference: 咖啡精品學 author:韓懷宗