The invention discloses coffee beans and a
fermentation method thereof. The method comprises the following steps of: soaking peeled coffee berries in water, inoculating
lactic acid bacteria, sealing with gauze, and performing anaerobic
fermentation for 36-72 hours, wherein the pH value of the
fermentation liquor at the fermentation end point is 3.35-4.00, thereby obtaining the coffee beans without a
viscous liquid layer; and washing the obtained coffee beans with water,
drying, shelling, and baking, thereby obtaining the finished product coffee beans, wherein the
lactic acid bacteria consist of more than one of
lactobacillus plantarum,
leuconostoc mesenteroides or
lactobacillus casei. According to the method disclosed by the invention, the
lactic acid bacteria are inoculated for fermentation, the metabolic characteristics of the lactic acid bacteria are fully utilized, the coffee
viscous liquid layer and nutrients of the bean bodies are utilized, the fermentation is performed in the liquid, anaerobic and acidic conditions suitable for growth of the lactic acid bacteria and
saccharomycetes are created, the contact area between the strains and the bean bodies is increased, the fermentation process is accelerated, the
coffee bean viscous liquid layer is effectively removed, the
flavor precursor substance composition of the obtained raw beans is changed, and the final
flavor quality of the coffee beans is improved.