Ask the Rennet Expert

What Is the Most Common Mistake When Using Rennet?

Short answer

Using ultra-pasteurized milk, or milk that is too cool, and then blaming the coagulant. In most failed-set calls we take, the problem is upstream of the bottle.

By Luis, Founder & Rennet Expert at Bixa ProductsUpdated June 20, 20263 min read

When someone calls me and says the rennet did not work, I ask three questions before anything else: what milk, what temperature, and how old is the bottle. Most of the time we have the answer inside two minutes.

The second most common one is changing several things at once. New milk supplier, new dosage, warmer room — and now nobody can say what caused the difference.

Technical information to be supplied by Bixa.Video answer and transcript for this question.

About the author

Luis — Founder & Rennet Expert at Bixa Products

Luis is the founder of Bixa Products. He has spent his working life around cheesemaking ingredients, first in the Latin American market and now in the United States, helping cheesemakers understand how coagulants behave in real production conditions. He answers questions about rennet, chymosin, coagulation and dosage in the Ask the Rennet Expert series.

Founder, Bixa Products
Rennet, chymosin and coagulation specialist
Family business with 30+ years in the Latin American cheesemaking market

Keep reading

All articles

Troubleshooting

Common Coagulation Mistakes

The most common coagulation mistakes are using ultra-pasteurized milk, adding coagulant to milk that is too cool, diluting in chlorinated or warm water, stirring during the set, and changing more than one variable per batch.

6 min read

Cheesemaking Science

Can Pasteurized Milk Be Used with Rennet?

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.

5 min read