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Cheesemaking Science

Can Pasteurized Milk Be Used with Rennet?

Short answer

Yes. Standard pasteurized milk is used with rennet every day in artisan and commercial cheesemaking. The problem case is ultra-pasteurized or UHT milk, whose heat treatment interferes with forming a cuttable curd.

By Bixa Products, Editorial teamUpdated March 8, 20265 min read

Standard pasteurization vs ultra-pasteurization

Standard pasteurization uses relatively moderate heat and leaves the milk proteins largely able to form a normal curd. Ultra-pasteurization and UHT use much higher temperatures, which denatures whey proteins and lets them interact with casein in ways that hinder gel formation.

The practical result: with UP or UHT milk you may get something soft and yogurt-like that never gives a clean break, no matter how much coagulant you add.

Working with pasteurized milk

  • Choose standard pasteurized, non-homogenized where available.
  • Some cheesemakers add calcium chloride to compensate for calcium lost or shifted during processing and cold storage — follow the guidance for your process and any legal limits in your market.
  • Keep addition temperature and pH consistent, since pasteurized milk offers less margin for error than fresh raw milk.

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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