HOW CHEESE IS MADE
Cheesemaking is such a varied process that it’s easiest to start with the details of one familiar variety—in this case, cheddar—and then touch briefly on some of its family members.
Pasteurizing the Milk
The majority of cheese produced in the United States is made from pasteurized milk—that is, milk heated to a bacteria-killing temperature (161 degrees Fahrenheit for standard pasteurization) for at least 15 seconds. After pasteurization, the milk is cooled to a temperature at which beneficial bacteria can be introduced and nurtured. According to FDA regulations, only cheese aged for more than 60 days can contain raw (unpasteurized) milk, which means that many soft cheeses like raw-milk Camembert that are treasured in Europe and Canada (particularly Quebec) aren’t available in the United States. But public health concerns about unpasteurized milk are controversial, and are challenged by experts such as food scientist Harold McGee, author of On Food and Cooking.
Adding the Starter Culture
Once the milk has been pasteurized, a bacterial starter culture is introduced. This culture acidifies the milk and eventually provides much of the cheese’s flavor by breaking down proteins and creating amino acids. Most cheesemakers obtain their starter cultures from culture houses (companies that make and sell cheese bacteria), which create custom, proprietary blends.
Cheesemakers use sanitized stainless steel vats and pipes to help ensure that unwanted bacteria and phage (viruses that prey upon bacteria, thereby killing the culture) stay out. In addition, a number of traditional processes such as salting, brining, waxing,
Mozzarella at Saputo’s Waupun,
Wisconsin, cheese plant. and washing help the cheese develop with the aid of only the microfauna the cheesemaker invites to the party.
The starter culture can, in theory, be obtained from the bacteria that drift through the air, given the right food (a bucket of whey is a classic choice) and enough time. But it’s more difficult to control. Artisan cheesemakers who work with native starter cultures reap the advantages of terroir—a unique link between the cheesemaker, the land, and the cheese—but risk ending up with an inconsistent product.
This enzyme, which comes in liquid or tablet form, separates the whey from the curd by allowing casein (milk protein) particles to bond together, creating the gel that is the backbone of cheese. These days, rennet is usually derived from vegetable sources rather than ruminants’ stomachs.
curds from whey.
Screens are dragged through the gelled curd (either by hand or, more commonly, with machines) to cut it into more manageable pieces. Excess whey is drained off and used for other things (including animal feed and protein supplements).
In the case of cheddar, even more whey is drained off, to prevent the cheese from becoming bitter. Then the curds are salted and heated, causing them to knit together into a pliable substance not unlike the children’s modeling foam called Floam. This is known as “cheddaring.” Next, the curds are shoveled into piles, which begin to flatten under their own weight.
Cheddared or stirred curds are pressed into round forms, then released from the forms and stored in curing rooms. The size and shape of the forms vary widely. Wisconsin master cheesemaker Kerry Henning once made two 12,000-pound cheddar cheeses to fill special orders from a Texas-based specialty supermarket chain. “Then they had to take out the front wall of the store where the glass is and two cash register aisles to wheel this thing into the store,” Henning recalls.
Cheddaring curd at Widmer’s Cheese Cellars
in Theresa, Wisconsin.
Blocks of immature Limburger cheese
at Chalet Cheese in Monroe, Wisconsin.
Ripening (or Affinage)
The intensity and importance of aging vary from cheese to cheese, even within varieties. Parmesan and provolone, for example, are aged for different lengths of time for dramatically different flavors. Cheese can be aged in warm and humid rooms, refrigerated rooms, or subterranean caves or cellars, all of which produce different textures and flavors.
A waxed paper, parchment paper, or bandage wrapping is typically applied to a cheese intended for extended aging, such as a hard English, Italian, or Swiss cheese. This keeps undesirable microfauna from infiltrating the wheel or block.
Alternatively, the outside of cheeses can be rubbed with anything from wine, beer, cocoa powder, and paprika to soybean oil, olive oil, salt, coffee grounds, grape must, espresso, lavender, tomato paste, rosemary, and ancho chiles.