Abstract: The Chinese yam and the malt was used as the raw material to saccharificate wort with enzyme,added beer yeast to ferment, prepared yam beer. The fresh Chinese yam was prepared powder,was saccharified by compound enzyme with the malt. The effects of addition level of compound enzyme,addition phase,action time,and addition quantity of yam powder on the reducing sugar content and α-amino nitrogen content of mix wort were studied by orthogonal tests. The results showed that the best technocal conditions were summed up as follows: 0.36% mix enzyme addition quantity, addition mix enzyme at 45℃, 17 min heat preservation and 35% yam powder addition quantity.The mix wort preparing with Chinese yam and malt was metabolized by yeast, higher alcohol content, diacetyl content, and alcohol degree in product beer were 55.8 mg/L, 0.06 mg/L and 3.91% respectively(the attenuation real degree was 67.2%). The product beer not only had the flavor of beer produced by barley malt but also contained multiple amino acids and anticancer substances, is one kind of better function drinks.

Key words: yam, beer, higher alcohols, diacetyl, malt