Coagulating enzymes, Chymosin, Pepsin

Rennet consists of two active components - chymosin (sometimes referred to as rennin) and pepsin. These two components are both enzymes which are secreted into the stomach of animals. In the new-born calf chymosin predominates in the secretions (95% chymosin / 5% pepsin). As the animal ages, or its diet changes from milk to grass, these secretions change and at about nine months of age the secretions have reversed (10% chymosin / 90% pepsin).

Both these enzymes (and other proteases) possess the power to coagulate milk by destabilising the casein micelle and causing them to clump together:

• Chymosin is nature designed to be specific in its action on milk and hence is the preferred enzyme of cheese makers, giving the highest cheese yields.
• Pepsin is a general protease and with its non-specific action results in a small reduction in cheese yield.

Broad spectrum proteolytic activity can cause serious cheese quality defects, including bitter flavours and a weak body.
RENCO Natural Calf Rennet is naturally very high in chymosin and gives the best results.