The first true step in cheese making is to inoculate the milk with culture and set the curd. Here’s a step-by-step breakdown of this procedure.
1. Heat the milk
Milk needs to be warmed up to the right temperature for the cheese making bacteria to culture.
I generally do this very slowly on my stove top, but you could also do it in the microwave, or in a basin of hot water. Which ever way you choose, make sure that you don’t over heat the milk. You don’t want to denature the proteins (like you do in yogurt making) and it takes a long time for milk to cool back down to the right temperature.
The temperature you need to heat to depends on the type of milk and whether you’re using a mesophilic or thermophilic culture. In general goats milk is heated to 88F (31 C) regardless of culture; for cows milk mesophilic is 90 F (32 C) and thermophilic is 91.5F (33C).
2. Add the bacterial culture
Once the milk is at the right temperature, stir in the culture. Then maintain the milk at the correct temperature while the bacteria start to digest the lactose. This is the acidification of the the milk, and it is important to achieve the right level of acidification for each particular cheese.
If you were a cheese producer, you would test the acidity levels, however, it’s not necessary for homemade cheese, and simply culturing at the right temperature for the right amount of time will work well enough.
I maintain the temperature of my milk using my Brød & Taylor Bread Proofer & Yogurt Maker, but you could also use the more traditional method of nesting the pot in a basin of warm water, and maintaining the temperature by adding more hot water as needed.
Set the curd and condition the milk
Add your liquid rennet or rennet tablet to a small amount of chlorine free water and mix it into the milk. Stir thoroughly, mixing the milk up from the bottom of the pot.
If you need to condition your milk with calcium chloride (which you need to do if you are using goats milk or pasteurized milk), mix 1/4 tsp of liquid calcium chloride into 1/4 cup of chlorine free water per gallon of milk. Thoroughly stir into your milk. You can condition your milk right after you’ve added the rennet.
Continue to maintain the temperature of the milk, without stirring, while the rennet curds the milk.