The research shows that high-temperature koji-making is a way to improve the flavor of liquor, but it will do harm to the taste of liquor. The reason is that the higher the koji-making temperature is, the lower the saccharifying power, liquefaction power and fermentation power of Daqu will be, and the koji-making quantity will definitely increase, and the increase of koji-making quantity will produce bitter substances such as polypeptide, kojic acid and casenol in fermented grains, which is also the reason why the koji-making quantity is generally large and the taste is more exciting. On the contrary, the relative "low temperature koji making" means higher microbial activity, which is easy to promote the production of rich small molecular nutrients in the brewing process, thus improving the softness of the taste and the health of drinking.
"Low temperature into the pool, slow fermentation" is regarded as the core technology of soft wine. According to professionals, slow fermentation at low temperature can prolong the time to reach the ignition period, make the metabolites react completely, ferment nutrients thoroughly, and slowly form and enrich alcohol and sweet substances in wine. At the same time, alcohol fermentation is slow and irritating.