Rennet - Testing Strength

[Alice in TX/MO]

I just started a new bottle of veal rennet, and it is NOT acting the same as the last bottle I got from the same source.  The curds are not firm enough.

Is it possible to have a defective rennet?

Alice

[linuxboy]

Might be old or damaged from heat exposure.

[Alice in TX/MO]

I've ordered a new one.

Is there some way to test this so I can adjust the 'dosage'?

[linuxboy]

The way it's done commercially to standardize IMCU/ml is you take a reference rennet (CHR Hansen makes it) and your rennet, and you see how long it takes to coagulate a volume of rennet and a volume of milk. Say, 1 ml rennet and 100 ml milk. Then you do the same for the test rennet and compare the two. There are a few ISO standards that govern all that.

Practically what you can do is measure out something like 1 cup milk and your normal dosage of rennet for 1 cup, and see how long it takes to flocculate. Then adjust the amount you need for the large batch to reach the target flocculation for your cheese type (10-15 minutes for most cheese)

[Alice in TX/MO]

Ok, I did the test with one cup of milk.  It set ok.

Maybe I need to add calcium chloride to the goat milk, as it's late in the lactation cycle.