Rennet is an enzyme commonly used in cheese-making to coagulate milk. Whether rennet is halal depends on its source.

Animal-derived rennet – Rennet extracted from the stomach lining of calves or other animals is only halal if the animal was slaughtered according to Islamic rites. If the animal was not slaughtered properly or comes from a non-halal source (such as pork), the rennet is not halal.

Microbial rennet – Rennet produced from fungi or bacteria is generally considered halal, as it does not come from animal sources.

Plant-based rennet – Rennet derived from plants, such as certain thistles or fig trees, is also generally halal.

When purchasing cheese, look for halal certification to ensure the rennet and all other ingredients meet halal standards. If certification is not available, check with the manufacturer about the source of rennet used.