Adjusting Pasteurized and/or Homogenized Milk
Cheesemaking is a journey into the magical science of bacteria growth that results in a tasty, nutritious food product. Experimentation in the kitchen is a majority of the fun but sometimes it is hard to gather the most optimum raw ingredients that form the basics to the cheese: most importantly, the milk. Cheese is affected by everything that happens before and after the cow was milked: the way the animals were fed and cared for as well as how the milk is prepared for the consumer.
Raw milk is often the best choice for cheesemaking, but not available in every state. Many people believe that raw milk is higher in nutritional content than conventional milk. Cows that produce raw milk eat grass rather than the grain of conventional operations, and the raw milk has been shown to have higher levels of conjugated linoleic acid (CLA) and essential fatty acids.
However, most consumers find that pasteurized milk is the only kind available to them. The process of pasteurization heat-treats the milk to kill any harmful bacteria. The temperature for pasteurization is normally 161°F. Ultra Pasteurization (UP) or Ultra High Temperature (UHT) pasteurization brings temperatures much higher; generally around 190° to 212°F or even up to 280°F. Milk that has been heated this much does not usually work well in cheesemaking, since the proteins have been destabilized and as a result the calcium in the milk does not bond properly to make a good curd. If your milk has been pasteurized at ultra-high temperatures, it will say “ultra-pasteurized” on the label, or have the initials UP or UHT. If you know the dairy your milk is coming from, you can consult them directly to find out how their milk is prepared for you.
Homogenization is a way to make conventional milk smooth and creamy by forcing the milk through a nozzle that breaks down the fat globules. These smaller fat particles then hold their suspension in the milk, so the cream does not separate and rise to the top as it does in non-homogenized milk. In the making of cheese, this homogenization can lead to a softer, weaker curd and may cause difficulties in coagulation.
As a home cheesemaker, you can avoid homogenization by mixing nonfat milk and heavy cream together (neither is usually homogenized) to reach the same proportion of fat as is found in whole milk. The ratio is 1 pint of heavy cream for each gallon of nonfat milk. An alternative is finding stores that carry non-homogenized milk, also called “cream-top” milk.
If your curds are too soft as a result of using homogenized milk, you can try adding calcium chloride (CaCl) or slightly increase the amount of rennet. To use calcium chloride, dissolve it into non-chlorinated water and add to the milk before coagulation.
There is really no way to compensate for milk whose proteins have been compromised by ultra-pasteurization. If you want to make cheese at home, you simply must find a source of raw or conventionally pasteurized milk. However, you can improve the consistency of your cheese by combining non-homogenized nonfat milk and non-homogenized cream to make your own “whole” milk.
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