How Cheese is Made: Exploring the Diversity of Cheese
How many different ways could their really be to make milk into cheese? As it turns out, there’s a LOT. While cheese making is simple in its fundamentals – milk is curdled, curds are processed, and processed curds are ripened – each step in this process provides endless options for the creative cheese maker. Here are truly just a few variations:
Step 1: Selecting the Milk.
This step in the process affects the flavor and nutritional value of the cheese.
- Cow: With the most prolific milk-producing cows making an average 80lbs of milk a day, it’s easy to understand why cow’s milk is the most popular milk source for cheese makers. Besides abundance though, cow’s milk is a good choice for cheese makers who want more color (cow’s milk has the most carotene of conventional milk sources) and a milder flavor.
- Goat: The second most popular milk source for cheese, goat’s milk has a rich, tangy flavor that is most pungent when fresh and mellows out as it ages. Cheese makers appreciate goat’s milk because it’s naturally homogenized, so the cream is evenly combined with the milk. People like it because of its distinctive flavor and it’s naturally lower lactose content (easier on sensitive stomachs.)
- Sheep: While sheep’s (or ewe’s) milk cheese is very popular overseas, it a product that’s only beginning to appear in the US. Too bad for us! While sheep’s milk is generally too rich to be enjoyed on its own, its high fat and protein content make an amazingly savory cheese that’s slightly sweet and slightly nutty. In fact, it was a French sheep’s milk cheese, “Ossau-Iraty,” that was recently named best cheese in the world!
- To Pasteurize or Not to Pasteurize? While some countries have banned raw milk and raw milk products outright for the risk of bacterial diseases associated with them, others argue the risk is overstated and further, that raw milk is actually better for you than pasteurized. Now today, while the manufacturing trend is still heavily in favor of pasteurized milk (even in countries without pasteurization laws), there are a growing number of people requesting and making raw varieties. Pasteurizing cheese is known to change its flavor and raw milk is often considered to make a superior cheese.
Step 2: Curdling the Milk.
This step in the process is probably the most important factor in final texture of the cheese.
- Starter Culture: Except in the very most basic cheeses, bacterial cultures are selected and added at this point. While rennet will work quickly to curdle the milk, the bacterial blend will work slowly over time to break down the resulting curd proteins and enhance the flavor and texture of cheese as it ages. Different cheeses use different bacterial strains. Sometimes it’s day old whey, sometimes it’s a bacterial blend. Swiss cheese wouldn’t have its holes without the very specific type of bacterial strain used to make it! Bacteria are a big part of what makes one cheese unique from another.
- Rennet: Though most people don’t realize this, most cheese is not vegetarian. In all but a few varieties of cheese, rennet, made from the stomach of an un-weaned calf, ewe, or kid (depending on the sort of cheese being made), is used to curdle the chosen milk – separating the whey from the solid curds. This is done because the acid in the stomach is specifically designed for breaking the milk down. Animal-derived rennet produces strong, stretchy curds and is used to make most hard cheese varieties.
- Vegetable Rennet: While there are vegetarian replacements that can also make a hard cheese, they do taste different from those produced with animal rennet. In most cases, experts can easily pick out the vegetable flavor and some types of vegetable rennet are considered unsuitable for cow or goat’s milk cheese due to a bitter flavor they produce. Thistle rennet is used in a traditional Portuguese sheep’s milk cheese, sera de estrella which develops a rind on the outside, yet stays soft like brie on the inside. Nettles can be used to make a semi-hard cheese like feta or gouda. Fig leaves and juice are another popular, traditional vegetable rennet option and they are sometimes used to wrap even animal rennet cheeses.
- Acid: Cottage cheese, cream cheese, ricotta, feta, paneer, and queso fresco are all rare examples of cheeses that do not traditionally contain rennet. Instead, they rely on milder acids from citrus, vinegar, or buttermilk. As a result, cheese made this way tends to be softer, less dense, and saltier. These are typically considered fresh cheese and are not suitable for aging.
Step 3: Processing the Curds.
This step in the process is where most variation occurs. Even curds made from the same milk and curdling ingredient can become completely different flavored and textured cheese after this step.
- Draining: The very simplest cheeses may be salted, packaged and ready for consumption after just draining the whey from the curds.
- Heating: To force more whey out of the cut curd and change the taste, some hard cheese are heated after heated after being drained.
- Stretching: The curd of some stringy cheeses like mozzarella and provolone are stretched and kneaded under hot water after their whey is drained.
- Cheddaring: Cheddar and some other English cheese get their characteristic texture from a long process of mixing called cheddaring. This helps to smooth the individual curds before they are pressed.
- Washing: To reduce their acidity, some mild tasting cheese like Edam, Gouda, and Colby are rinsed with water after whey is drained from the curds.
- Flavoring: Beside the usual salt added to almost all cheeses, some specialty cheeses have added spices, herbs, fruits, or vegetables added just before the curd is ready for pressing.
- Pressing: Almost every cheese, whether fresh or aged, is pressed into a mold or form to achieve its final shape. The harder the desired cheese, the more pressure or weight the cheese-maker will apply. This is done to force moisture from the curds and bond them together.
Step 4: Ripening the Processed Curds.
This step in the process dictates how pronounced the flavors of a cheese’s chosen curdling ingredient and bacterial strain (if used) will mix with the flavors of the milk.
- Fresh Cheese: With little time to ripen, fresh cheeses tend to be the most mildly flavored and moistest of cheeses.Fresh cheese may be made in as little as half an hour and does not require aging.
- Interior-Ripened: Interior-ripened cheeses are cheeses where no new bacteria, mold, or yeast is introduced after curd processing and pressing. Instead, this cheese relies on the starter culture to ripen evenly through the cheese. To prevent outside influences, interior-ripened cheeses are either waxed or vacuum-sealed.
- Mold-Ripened: In contrast to interior-ripened cheese, mold-ripened cheeses are left exposed anddevelop a rind as bacteria applied to the surface of the processed, pressed curd “blooms.” To encourage a white or “bloomy” rind as with Brie or Camembert,penicillium is applied.
- Bacterial-Ripened: Like mold-ripened cheeses, bacterial ripened or “washed-rind” cheeses are left exposed to the elements and a rind is encouraged. “Red smear,” a mix of yeast and beneficial bacteria, so called because of the reddish color it turns the rind, is applied to the surface.