Draining curds in cheesecloth. Photo by Tami Parr

The majority of cheeses that we’re accustomed to eating—all of those glorious Cheddars and Bries and blues—are made using rennet, a collection of enzymes that act as coagulating agents. There are several categories of rennet used by cheesemakers. Animal rennet is derived from calf stomachs. True vegetable-based rennets are derived from plants; some European cheeses such as Sera de Estrella from Portugal are made using thistle-based rennet. Most rennet used in commercial cheese production comes from bacteria that have been genetically modified to produce some of the same enzymes found in animal rennet. This type of rennet, sometimes referred to as “vegetarian rennet” or “microbial rennet,” is also used to make kosher cheese. Rennet for home use is available from online cheese supply shops.

Most cheese is made by combining an acidifying agent with rennet. “The primary enzyme in rennet, chymosin, works better and faster at a lower pH,” says Dr. Goddik. When making fresh mozzarella, for example, citric acid creates the optimum conditions for the rennet to work its magic. Many artisan cheesemakers use bacterial cultures to accomplish the same result; cultures also contribute to the flavor profile of the end product.

Whey is the nutritious liquid by-product of the cheesemaking process. Though it looks like water, it actually contains additional proteins, minerals, and fats. In commercial cheesemaking, whey is produced in large quantities and then typically collected, dried, and used as a nutritional supplement in breads, cookies, and pancake mixes. Proteins in whey can also be used to make what’s known as “whey cheese.” Ricotta is probably the best known of the whey cheeses. Save the whey you create when making cheese and add it to smoothies, or use it as a substitute for milk when making bread.

Once curds are separated and whey is drained, the fun begins. “The rest of cheesemaking is a matter of further concentrating the milk solids,” notes Dr. Goddik. “Cheesemakers might heat the curd, stir it, or press it to try to expel as much whey as possible.” Blocks or wheels of cheese could then be soaked in brine, wiped with brandy, oils, or salt water, and/or wrapped in cloth or leaves. Cheeses might be aged several days or several years.

While it takes time and skill to create such classics as Cheddar or Camembert, making cheese at home can be a simple and rewarding project. Much like baking, the cheesemaking process combines precise science with a little bit of artistry and is all about patience and practice. Once you’ve mastered the basic styles, consider experimenting with more advanced cheeses—many adventurous home cheesemakers make and age tasty cheeses successfully in the confines of their own kitchen.

Tami Parr is the author of Pacific Northwest Cheese Project, an online chronicle of all things artisan cheese in the Pacific Northwest.

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