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Rennet 101

Does Rennet Expire?

Short answer

Yes. Rennet loses clotting activity over time, and faster if it has been stored warm or in light. A familiar dosage giving a slower set than usual is one of the most common signs of a coagulant past its best.

By Bixa Products, Editorial teamUpdated March 14, 20264 min read

What declining activity looks like

  • Set time creeping longer batch after batch with no other change.
  • A softer curd at the moment you normally cut.
  • More variability between batches from the same milk.

Planning around it

Buy quantities you will actually use within the labelled period, keep a first-in-first-out habit, and record the date each bottle is opened. For growing producers, ordering to a schedule matters more than ordering in bulk.

About the author

Bixa Products — Editorial 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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