Processed

Microbial Rennet

A tier

Microbial rennet is a protease from moulds such as Rhizomucor miehei, grown in a tank rather than taken from a stomach. It sets milk for vegetarian cheese and for plants that cannot secure calf extract. The curd forms, but the enzyme is often more proteolytic during ageing, which can turn a long-hold cheddar bitter unless the maker chooses a specially heat-labile or attenuated strain. It is the honest vegetarian alternative, not a flavour clone of calf rennet. Fresh cheeses and short-aged styles forgive it more than a two-year clothbound. Liquid and powder forms exist; dose by IMCU and watch bitterness in the make notes. Label it clearly—some traditionalists will not buy the wheel.