Why did the rennet not work to

form cheese curds?

“I followed the recipe for making cheese, but no curd formed. Is there something wrong with your rennet?”

Rennet does not go bad! Over time, it will probably loose effectiveness.  This means you might have to use a bit more.Rennet needs calcium in order to do it’s job and break the curd from the whey in milk. Calcium is always in milk, but there are a couple of things that will keep the rennet from be able to use it effectively.

First, in pasteurized or especially ultra-pasteurized milk, the process is goes through in pasteurization prevents the rennet from being able to use the calcium. So when you add the rennet to the milk in making your cheese, nothing will happen.

This is why we suggest you add calcium chloride to your milk as part of your cheesemaking process so that the rennet has plenty of calcium to do it’s work in forming curds and whey.

Second, in raw milk there are some conditions within the animal that produces milk that will also block the rennet from being able to use the calcium. Sometimes it’s a higher somatic cell count. This doesn’t necessarily mean the animal has mastitis. Rather it might be happening as the animal gets closer to the end of her milking cycle.

So what do you do to keep producing cheese and not waste milk?  We suggest you just make a habit of adding calcium chloride to each recipe.  This way you will always have a consistent outcome in making cheese.

The Calcium Chloride we sell is a very natural product… it is a very concentrated salt type solution with calcium as the main ingredient rather than sodium used in table salt. We now add calcium chloride to all of our cheese making kits.