Papain is added to beer before filtration and packaging. It was the first haze preventative used in the brewing industry. The enzyme is capable of digesting dissolved proteins—with amino acids as a by-product—and thus increasing the clarity of beer. In brewing, papain is used to digest excess proteins after fermentation, because high protein levels can cause hazes, high viscosity, and excess foaming in the finished beer. Papain is also very resilient and acts under a wide range of conditions including high and low temperatures. This makes it suitable for many applications, particularly in foods with low pH and during beer processing at low temperatures. In the U.S.A. 80% of the beers are made chill-proof by using Papain.