Calcium has a beneficial effect on the precipitation of wort proteins, both during mashing and during the boil. Proteins are also degraded, that is converted to simpler substances by proteolytic enzymes called proteases. FAN compounds are utilised by the yeast during fermentation for the manufacture of Amino acids, and an increase in FAN levels in the wort improves the health and vigour of the yeast. High protein levels in beers also have negative effects, making beer more difficult to fine and encouraging formation of hazes, in particular chill hazes. Product shelf life can also be adversely affected.
Calcium ions protect the enzyme a-amylase from inhibition by heat.
The drop in pH encouraged by Calcium ions in the mash and copper helps afford the wort and subsequent beer produced a greater resistance to microbiological infection. The reduced pH of the sparge liquor reduces extraction of undesirable silicates, tannins and polyphenols from the mash bed. The extraction of such materials is encouraged by alkaline sparge liquor. These materials are very undesirable, contributing to harsh flavours, hazes in the finished beer and decreased beer stability. Calcium precipitates oxalates as insoluble calcium oxalate.