Rennet is the coagulant that is used to set a curd when making cheese. Traditionally rennet is made from an enzyme found in the stomachs of baby calves, goats or lambs. Vegetable rennets are obtained from a type of mold, and there are also plant-based rennets such Thistle rennet. Rennet comes in tablet, liquid and powder form.
To use your rennet, you first must dilute the desired amount in non-chlorinated water (we use distilled water but if you have a good filter on your water source, that will generally take all the chlorine out of the water). If using rennet tablets, just be aware that 1 tablet = 1 teaspoon and when you dilute it in the water it won’t actually dissolve. Use your diluted rennet within 30 minutes or it will lose its effectiveness.
Rennet has a limited shelf life – liquid rennet lasts for 7-8 months when refrigerated and tablets last for up to 5 years when stored in the freezer (2 years at room temp). If you are unsure how old your rennet is or whether or not it is still effective, you can do the following test:
- Heat one cup of milk to 90F.
- Dilute ¼ tablet or ¼ tsp liquid rennet in ½ cup non-chlorinated water.
- Take 2 tsp of the diluted rennet and add it to the milk.
- Stir gently for 30 seconds.
- If the rennet is working, the milk surface will form a slight film in 2 minutes and will have formed a firm curd within 6 minutes.
If not, it might be time to get some new rennet!
Now, are you ready to learn more about how exactly to make cheese with rennet? Visit our ON DEMAND class page for over 50 cheesy choices and take $5.00 off any class with coupon code “$5off!“
Submitted by Kate Johnson