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Rennet 101

What Is Microbial Rennet?

Short answer

Microbial rennet is a milk-coagulating preparation produced by microbial fermentation rather than taken from animal stomachs. It does the same job in the vat: destabilising milk protein so a curd forms.

By Bixa Products, Editorial teamUpdated January 22, 20266 min readReviewed by Luis

Where it comes from

Microbial coagulants are produced by fermenting selected microorganisms that generate milk-clotting enzymes. The enzyme is then recovered, standardised for clotting strength and supplied as a liquid, powder or tablet.

Because no animal stomach is involved, microbial rennet is the coagulant most commonly used for cheese intended for vegetarian consumers.

Why fresh-cheese producers use it

  • It is widely available and consistent in supply.
  • Liquid formats are easy to dose accurately at both small and production volumes.
  • It suits the fast turnaround of fresh cheeses, which are eaten young rather than aged for months.

Are all microbial rennets the same?

No. Different microbial coagulants differ in clotting strength and in how they behave through a make. That is why dosage cannot be copied from one product to another, and why a change of supplier is worth a small trial batch.

Frequently asked

Is microbial rennet the same as vegetable rennet?

No. 'Vegetable rennet' usually refers to plant-derived coagulants such as thistle. Microbial rennet is produced by fermentation of microorganisms.

About the author

Bixa ProductsEditorial team

Educational content written by the Bixa Products team, a family-owned cheesemaking ingredient company specializing in rennet and chymosin. Technical guidance is written conservatively: where a value depends on your milk, process or product, we say so instead of guessing for you.

  • Family-owned cheesemaking ingredient company
  • 30+ years in the Latin American cheesemaking market
  • Specialists in rennet, chymosin and milk coagulation

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