How Cheese gets made
Cheesemaking starts with curdling milk with acid, and separating the curds (solids) from the whey (liquids, with some protein)
Curdling happens by introducing acid (like vinegar), or specific bacteria (which process the lactose sugars into lactic acid)
After that, the curds are processed - either by extra processes to remove liquid (hard cheeses), adding mold (blue cheeses), or just with more additives for flavor (salts, peppers, bacon?)
Hi folks! I wanted to dip into something extremely relevant to my interests… cheese.
The process
Milk has two primary proteins: casein and whey. To start the cheesemaking process, you need to separate them. This is curdling. Casein turns into the cheese curds that you can just eat. And whey is kind of a watery leftover that gets discarded (though you can use it to make ricotta). Curdling is done by making the milk acidic, and is usually done in two ways:
Adding an acid, like vinegar. This creates crumblier curds, and it’s used for things like Paneer.
Adding a bacteria culture. The bacteria turns the lactose sugar in milk into lactic acid, which starts the curdling process. This is the more common process. Rennet is also often added to help things along. It makes the curds stronger and more rubbery, and lets curdling happen with less acid.
(Small aside. Rennet is found in the cow’s 4th stomach. It helps process the coagulation process by cutting up K-casein, which in its natural form repels other casein. After getting processed by Rennet, the casein can coagulate into curds much easier).
At this point, the curds are pretty gel-like. For soft cheeses (like Brie, or Camembert), this is good enough - they get drained, and move on to their next steps.
Harder cheeses need more work to draw out moisture. There are a few techniques:
They get cut (physically). The smaller the pieces, the more whey gets extracted, and the harder the end product is.
They get heated.
They get cheddared. This is a specific process where curds are cut into long strips, and stacked on top of each other. They get periodically turned and stacked. The weight helps whey get pushed out of the lower layers.
Post-processing
Hard cheeses tend to get heated to extract more whey. Salt gets added to draw out water, and to prevent bacterial growth. The cheese then gets “ripened” (it dries, bacteria/mold/enzymes can break down the internal proteins and fats for added flavor) - this can last from days to years. A wheel of Parmigiano-Reggiano* can be aged for three years.
Variations in Cheeses
There’s a lot of ways to get different cheeses.
You can use different types of milk! Cow, goat, sheeps, camels, reindeer… each has a slightly different composition.
Bacteria. Most cheeses use the Lactococcus lactobacillus strain. Swiss cheese uses a distinct strain of bacteria, which generates more carbon dioxide during the process (which forms the holes).
Washing. The curds get washed in warm water, which makes the taste milder. Gouda and Colby are washed.
Stretching. The curd gets stretched and kneaded, which gives it its more fibrous texture. This happens to Mozzarella.
Ripening. Bacteria, latent enzymes, molds, can all act on the cheese’s components and give it more flavor.
For example, Camembert cheese involves Penicillum camemberti which breaks down proteins on the surface.
Blue cheeses (like Roquefort) are a special case of mold. They use a different mold, which only gets “activated” by air. So when the cheese is set, holes are poked into the top, which lets the mold start and propagate in those blue veins.
People also add extra ingredients too (salts, peppers, gelatin, etc.)
There’s obviously a lot more that happens here - the cheese world is immense. If you want to read more, there’s a few references below.
As always, if you have things you’d like to learn about, feel free to email us at (davidren.mailbox@gmail.com).
*If you find yourself in New York City after indoor dining returns, Basta Pasta on 17th st has a dish where they roll up to your table with your pasta inside one of said cheese wheels, and scrape out cheese during serving for great flavor and joy.
Some references:
(I love that there’s a separate wiki entry just for the history of cheese).