As we known, the beer basic materials are water, beer hops, yeast, and malt. In this one, yeast decides to beer fermentation type, and in meantime decide beer types. The beer fermentation has two types, one is Top-fermented beers, and another is Bottom-fermented beers.

Fermentation is the process by which fermentable carbohydrates are converted by yeast into alcohol, carbon dioxide, and numerous other byproducts. It is these byproducts that have a considerable effect on the taste, aroma, and other properties that characterize the style of beer.

Fermentation is at the heart of the craft brewing process. During fermentation, the wort made from the raw material is converted into beer by yeast. Fermentation is when yeast produces all the alcohol, aroma and flavor compounds in beer. It is also “where the magic happens”. Fermentation is divided