Abstract: It is very common that the sluggish or even stuck fermentation occurs during the cider making, especially basing on the concentrated apple juice. The main reason is the lack nutrition of yeast, including the Yeast Assimilable Nitrogenous Compounds(YANC) and the vitamins. So we designed the single factor experiments, to find out the optimum adding quantity of the eight nutrition factors, including ammonium monoacid phosphate (DAP), ammonium sulfate, thiamine, inositol, biotin, nicotinamide, pyridoxine and pantothenic. It is indicated that the content of the alcohol reached the highest point when the adding quantity of mmonium monoacid phosphate (DAP), ammonium sulfate, thiamine and biotin is 400, 1200, 0.30 and 0.20mg/L respectively.

Key words: sluggish fermentation, cider, Yeast Assimilable Nitrogenous Compounds(YANC), vitamins, concentrated apply juice