A large barrel of draft beer is equivalent to 10 bottles of beer, a medium barrel of draft beer is equivalent to 9 bottles of beer, and a small barrel of draft beer is equivalent to 3 bottles of beer.

Draft beer is filtered by microporous membrane, while ordinary beer is sterilized at high temperature. Draft beer is a kind of pure natural, without pigment, preservative, sugar and essence, and it is extremely rich in nutrition.

In the process of brewing beer, the germinated barley is first crushed in a roller mill, mixed with hot water, and then rotated into a wort barrel (a large container made of copper, wood or stainless steel in the brewing workshop). Like oatmeal, wort is golden yellow and a little sweet. The method of boiling wort was developed by German winemakers according to their malt types. They first pumped the wort into a tank, boiled it to promote protein decomposition, and then pumped it back to the wort barrel, slowly raising the temperature within a few hours. This method was originally applied to the brewing of German white beer (Weissbiers) and German back beer (Backs), with the aim of brewing a beer with strong malt style.