Rennet - an enzyme that coagulates protein. Available in two forms:

• animal rennet comes from calf or lamb stomach fed on mother's milk,
• plant rennet - microbiological rennet; does not contain animal protein.

Curd - a more compact and denser milk consistency obtained by adding rennet. The curd contains most of the proteins present in milk and fat.

 

If we notice how much time it takes for rennet to start the coagulation process, we can calculate the time it takes for the milk to curd - it is about 2.5 times longer.
Here are two ways to determine if your milk has started to curd:

• Put a sterile clean toothpick on the surface of the milk. When the coagulation starts, the toothpick will stop moving.
• Let the water drop onto the surface of the milk. If it rests on the surface or makes a small depression in it, it means that the coagulation process has started.