With all the talk this week of microbes, dairy and culturing, some of you out there are probably wondering what the difference is between yogurt making and cheese making. Oh who am I kidding? No one’s probably wondering that. But I have no other ideas for an intro and it’s mid-afternoon already.
As it happens, the process of yogurt making is almost identical to the process of cheese making, save for one critical thing: chymosin. Chymosin is the protein-digesting enzyme that’s responsible for curdling milk into solids that can be formed, salted and aged. Yeast and bacteria don’t have the muscle to curdle proteins into those kinds of big, firm curds, however they can make itty bitty yogurt curds of a kind that can be strained to make a kind of pseudo-cheese.
All you need is some cheese cloth, a wooden spoon and pot. You scoop the yogurt into the center of a double-layer of cheesecloth, tie it up into a bundle, and suspend the bundle inside the pot, tied to the spoon. A few hours later (up to 24 depending on how runny the yogurt is) enough of the liquid whey will have dripped out and something that looks and tastes very much like cream cheese will be left (Labna is what’s it’s called in Lebanon, and in fact when you mix it with little chopped mint, basil or thyme, it’s fantastic shaped into balls and drizzled with olive oil).
This is as close to a cheese as you’ll get with yogurt as your starting point, but it ain’t half bad. And now for an overly detailed and long-winded discussion of the chemistry of cheese…
Just kidding. Some other time. (Maybe).
UPDATE: Reader Bronwyn from New Zealand adds:
You can, however, make perfectly good cheese with yoghurt as a starter culture if you add rennet, which contains chymosin, is available from the supermarket, and is what my mother used to use to make junket. All you need is a way to control the temperature of the curds for a few hours. I’ve made cheddar, provolone, mozzarella, and parmesan using yoghurt as my starter culture and it’s just fine. More than fine, in fact. Much nicer than Mum’s junket. Cheesemaking is a hell of a lot less complicated than people would have you think – so long as it’s not important to you that it turns out exactly the same each time you make it.