Research Progress in Influencing Factors of Higher Alcohols-Metabolic By-product of Beer Yeast

Higher alcohols,as the main compositions of by-product in beer brewing,are the main flavoring substances for beer.The formation approaches of higher alcohols include degradation metabolism and anabolism.Adequate higher alcohols content could increase beer body harmony and perfect beer taste and aroma.However,excessive higher alcohols would cause off-flavor in beer.Higher alcohols content in excess of 100 mg/L will evidently spoil beer taste.The standard higher alcohols content for bottom fermentation beer and top fermentation beer are 60～90 mg/L and less than 100 mg/L respectively.Higher alcohols content is mainly influenced by yeast species,wort compositions,and fermentation technical conditions.Accordingly,the above factors should be under proper control in the production.(Tran.by YUE Yang)