Most countries in the world use auxiliary materials for beer production, with the exception of Germany, which strictly abides by its "Beer Pure Brewing Law" formulated in 1516. Only four ingredients, water, malt, hops and yeast, are allowed in beer brewing, and no auxiliary ingredients are allowed.

The basic operation of decoction mashing is to take out a part of the mash and boil it, then pour it back into the main mash tank to maintain a constant mash temperature. There are two purposes for boiling part of the mash: Use physical methods to destroy the cell wall of starch cells in malt. Boili