Difference between main fermentation and post-fermentation

Full fermentation (mainly full fermentation) mainly refers to "enzymatic fermentation" and post-fermentation mainly refers to "microbial fermentation".

After the main fermentation, post-fermentation can be carried out. Pre-fermentation means that yeast uses the sugar in wort to reproduce, and sugar fermentation produces alcohol and CO2, as well as various flavor substances. Post-fermentation is to reduce the diacetyl produced by yeast before fermentation to below the standard when the sugar is basically used up. Upper fermentation and lower fermentation are classified according to the fermentation characteristics of beer. Upper fermentation. During the fermentation of beer fermented by this yeast, a large number of bubbles accumulated on the liquid surface for fermentation. Main fermentation, also called "pre-fermentation", is the main process of beer fermentation. In this process, yeast completes proliferation, anaerobic fermentation and precipitation recovery, which consumes most wort components such as fermentable sugar and assimilable nitrogen, and the discharged fermentation metabolites are the main components of beer. The main fermentation usually takes 6-8 days, and the length is 8- 10 days. After drinking, because the fresh beer still contains a small amount of fermentable sugar, the yeast is suspended again, and a more vigorous fermentation process appears in the wine storage tank, which is called "post-fermentation". Post-fermentation is a necessary process of traditional fermentation. Through this post-fermentation process, the odor of the original wine can be eliminated.