Understanding Cultures for Home Cheese Making

Reading Time: 5 minutes

Though people have been making cheese at home for millennia, the rules changed with pasteurization. Here’s how to use cultures for safe and successful dairy products.

Pieces of pottery confused archaeologists in the 1970s. The red clay shards were perforated, as if they had been baked while pierced with pieces of straw. Poland produced some of Europe’s first farmers so the shards were probably used for preparing food. Archaeologist Peter Bogucki had seen a similar tool at a friend’s house, used for making cheese at home, so he speculated the shards belonged to a cheese-making, colander-type tool. But at that time he had no way to test his theory.

About 40 years went by and the shards sat in storage. Then in 2011, Dr. Melanie Roffet-Salque analyzed fatty residues in the clay. She found signatures of abundant milk fats, meaning the early farmers had used the sieves to separate milk solids from whey. The shards became the oldest-known evidence of cheese-making in the world, existing since 5,500 BC.

Before that, scientists believed dairying dated back to 4,000 BC. A legend credits the discovery of cheese to an Arab trader who stored milk in the stomachs of ruminants, where residual rennet solidified the proteins into edible curds. But the Sumerians made cheese even before then. Curdling and salting hard cheeses was the only way to preserve goat milk benefits in a hot climate.

People from Sumer and Arabia had a problem. Adults, unlike children, could not produce the enzyme lactase, which allowed them to digest lactose. Milk was essentially a poison for them. Reducing lactose to tolerable levels was done by introducing the right bacteria. They learned how to make yogurt from scratch, adding samples from the last batch to a new container of milk. This created another food source that could keep people alive even if plant harvests failed. Yogurt is still a strong component in Middle-Eastern food.

But milk wasn’t a major food source for anyone until a mutation occurred.

About 7,500 years ago, coinciding with the archaeological discovery in Poland, Europeans developed a genetic tolerance to lactose, even into adulthood. Those of European ancestry still account for most people who can drink milk. With the mutation, cheese-making burgeoned. Cooler European climates allowed growth of beneficial microbes and molds that gave cheeses their delightful flavors. Some microbes already lived in raw milk; others came from the environment or from recycling whey from an earlier batch.

Pasteurization and the Changing Game of Making Cheese at Home

Cultured butter and sour cream were common prior to the nineteenth century. Cream sat at room temperature for a couple days before entering a churn. Households learned how to make butter early on, since it harnessed fat necessary for survival. Though cultured butter is still sold, it’s not as available. One reason is because dairymen learned that scalding and straining cream increased the keeping qualities of butter by killing the microbes. Another is because sale of raw milk products is illegal in many states. It’s quicker and safer to pasteurize cream then make uncultured butter within industrial settings.

Before America’s growth sent people out West, households kept dairy cows in urban areas. Raw milk wasn’t as dangerous because it was consumed soon after milking. When cities grew, cows were pushed to the countryside and milk was transported back to the city. This additional travel time allowed bacteria to cultivate. Now the US Centers for Disease Control says improperly handled raw milk is one of the world’s most dangerous food products, spreading tuberculosis, diphtheria, scarlet fever, Salmonella and E. coli. Pasteurization kills these dangerous microbes. It also kills the beneficial ones as well.

In 1987, the FDA banned interstate distribution of raw milk. Even if you can’t purchase it within your state, you can purchase the necessary cultures. Scientists began producing pure microbial cultures around the beginning of the twentieth century. These samples are constant and guaranteed; Listeria isn’t a problem if cheese is made with pasteurized milk and starter cultures.

The Right Cultures for Making Cheese at Home

France has over 3,800 cheese products made from either raw or pasteurized milk. But there aren’t 3,800 types of cultures. One culture can make many kinds of cheese, depending on temperature, ripening time, and environment.

The best place to find cultures for making cheese at home is from a company that specializes in cheese or brewing. Though cultures can be purchased on large Internet retail sites, most act as distribution only. The New England Cheesemaking Supply Company sells cultures, rennet and additional tools for crafting dairy products.

Softer products, such as yogurt, can be made by purchasing a small amount of the existing product in a grocery store. If the package contains “live and active cultures” and the milk sits at the proper temperature for adequate time, microbes grow. A quarter cup of real yogurt can ripen a gallon of milk.

Though buttermilk and sour cream can be cultured similarly, store-bought products don’t have a guaranteed culture strength. The microbes might not even be healthy by the time the carton resides in your fridge. The best buttermilk comes from a pure culture.

The biggest reason to purchase cultures from a supply company is because, if the culture is not strong enough, the milk may still ripen…but it will be because of other bacteria from the environment. That’s why dairies sanitize so rigidly and regularly. Cheese-making experts advise that raw products should be made with extremely clean milk that has been allowed to ripen for a short time before adding a little pure culture to keep the microbes constant.

Powdered cultures can be purchased in jars or small packets. New cheese-makers should try smaller quantities first. The packets can last two months unrefrigerated or over two years in a freezer. Rikki Carroll, owner of New England Cheesemaking Supply Company, wrote a book that teaches making cheese at home using quantities contained within the packets.

Thermophilic cultures ripen milk scalded to temperatures between 104 and 140 degrees. Milk for Mesophilic cultures should never exceed 102. Both can make a variety of dairy items. For instance, Mesophilic can make cheddar, Monterey jack, cream cheese and cultured butter. Additional cultures ripen sour cream, buttermilk and chevre, though some recipes can use Mesophilic as well. The best way to determine which culture to use is to first acquire a cheese-making book.

Culturing Safely

Remember that, while ripening dairy products, you are growing bacteria. They are good bacteria, but the perfect environments for the good also propagate the bad. Make sure you have minimal bad bacteria by using pasteurized milk or raw milk that has been collected safely. Even safe collection isn’t a guarantee. During the yogurt-making process, milk is often heated above 160 because it kills existing microbes so the only bacterial growth is intentional. Cheese made with raw milk must be cured at least sixty days in an air-free environment to ensure it is safe for sale.

Dairy products ripen at 70 to 120 degrees then are either cooled or coated with wax to stop bacterial growth. Be sure you ripen for the right amount of time, with the right techniques, to control the microbes. Cheese should be waxed completely so none of the surface is exposed. Homemade cream cheese or sour cream should be consumed within about a week.

Don’t let the science or precautions daunt you. It’s worth reading up on making cheese at home, understanding how cultures work, then giving it a try. Homemade cheese is a treat you can be proud to have made.

Do you like making cheese at home? What are your favorites to make? Let us know in the comments below.