A process, involving a material coming out of solution such as in a cold or hot break. A substance from which another substance is derived. The first stage of fermentation. Initial rapid stage of yeast activity when the simple sugars in the wort are metabolized. The vessel in which primary fermentation is carried out.
Proteins provide essential yeast nutrients and contribute to the body and head retention of beer.
During a protein rest large proteins are broken down to amino acids and smaller soluble proteins. The stability of finished beer is largely established during the protein rest. Nutrients required for proper fermentation also are developed during this process. Also know as protease. Enzymes naturally present in barley and malt that have the power to break up proteins in the mash.