Made from Scratch
Yogurt Revelations - Part I
Photos by John Rockwell
Up until the past 100 years or so, with advances in refrigeration, food storage and chemical preservation, people had to rely on microbes and natural processes to preserve their food over longer periods of time. Wine, beer, kombucha, pickles, bread, cured meat, cheese and yogurt are all part of that heritage of foods where human beings (unwittingly until recently) used microbes (and sometimes chemicals) to preserve protein, starches and liquids during seasons when fresh water, crops, dairy and meat weren’t always available. The invention of the electric refrigerator fundamentally changed the way people eat and live, shifting the responsibility of food storage and preservation to food companies in exchange for the assurance of year-round food availability. The benefits of cold storage are essential to urban societies separated from food production, but in the process, the art of the preservation of seasonal food has been lost.
Canning, pickling, brewing and other home-made items in those categories now either give you hobby status, or if you’re a restaurant, give you some gravitas in the “artisanal food” or “gastro” category. Aren’t we all a little more impressed when a gastropub makes its own pickles, even though mom and pop Mexican restaurants in SoCal have been doing this for the past 40 years?
After experimenting with Greek yogurt making the past few months, I am convinced that the process of making yogurt was a way to preserve milk that had soured, possibly milk that had started curdling, and was no longer drinkable. I’m convinced of this because as I sit here writing about yogurt, I’m eating some homemade Greek yogurt that is approximately eight weeks old—way past its “expiration date,” and it’s still wonderful and delicious. Under light refrigeration or room-temperature storage, it probably wouldn’t have lasted as long, but it would last longer than raw milk under those same circumstances.
The procedure for making yogurt is simple, and to disabuse any notions of what yogurt is, it is simply milk that you eat. Well, milk and a mixture of living yogurt cultures that ward off infections and mold. There are generally two version of it commercially available: “regular”—which simply means the whey hasn’t been broken out of it—and “Greek,” which means the whey has been broken out of it.
I’m a fan of Greek yogurt, but not all Greek yogurts on the market are equal. The ones that spend more money on marketing themselves to seem Greek are usually not quite as good. Look at labels. Avoid products where there are additions of fruit pectin, sugar or corn starch used to artificially thicken the product. None of that is required to make good, thick commercial Greek yogurt.
If you’re one of the few people who hasn’t tried Greek yogurt, a good reference point for a starter is the Fage Greek yogurt brand. The name is pronounced “Fah-yay,” and it is most definitely the “Budweiser” of Greek yogurts, based on sales and popularity. It’s definitely a gateway product. It has a thick, smooth texture, it’s a little grainy and earthy, and isn’t really sour. It is also very filling. There are a couple of other commercially available Greek yogurts which are just as good—maybe better—but have increased sourness levels, or “culture” flavors as industry people like to say. It’s almost like a mixture of ricotta cheese and sour cream, both of which are made with very similar processes. I’ll look more at the different types of Greek yogurt in the next piece.
I am going to describe the process for making Greek yogurt. You can make some today if you want and eat it tomorrow. It’s really that easy, and when you make it you’ll see why so many dairy companies jump in on this “value-added” product where they can take a relatively inexpensive resource like milk, process it for a few hours, and then sell it back to customers at many times the price of the original milk. It’s a lot easier to make with an Instant Pot or some other device that can hold a reliable temperature for a long period of time. But you could just let it sit in a jar or pot for additional time at room temperature, and you’d get a similar result. All you need is that pot, milk, a thermometer, about a cup of plain Greek yogurt from the grocery store (for live cultures), some cheesecloth and some containers for final storage. I do about 1-1.5 gallons of milk at a time which yields around three quarts of Greek Yogurt, give or take.
Step 1: Destabilize proteins and pasteurize. Use any milk you want, but as usual, stay away from ultra-pasteurized milk because it has been heated to a point where the proteins aren’t as reliable for use. Heat the milk to 180 degrees for about 30-40 minutes. This is just below boiling. Instant Pots have a setting where this is “automatic.”
Step 2: Cool to 110 degrees and add culture. Like any fermented product, you have to hit the right temperature before adding microbes. The Instant Pot is nice because you can remove the stainless pot, immerse it in ice-water while monitoring the temperature, dry it, and put it back in the Instant Pot when it hits 107-110 degrees. Then stir in a cup of store-bought yogurt, seal it, and let it ferment at 107 degrees for 8-12 hours. (This is a setting on your Instant Pot.) If you don’t have an Instant Pot, you may need to let it sit more than the 8-12 hours (more time=more sour) at room temperature (70-80 degrees). Of course, in SoCal, you could just seal the pot and leave it outside in the shade in the 100 degree heat and see what happens!
Step 3: After fermenting for 8-12 hours, it should be thick. Scoop the yogurt into a yogurt funnel or cheesecloth and strainer and let the whey drip out for around 1-2 hours. Then scoop your thick Greek yogurt into clean sealed storage containers. I use Ball jars, and the yogurt keeps well beyond the two weeks most recipes claim. Perhaps they claim this because it’s so delicious it is eaten before that time anyway!
Yes, there are things that can go wrong, but if you followed this basic procedure, you’re going to have something resembling yogurt. If you don’t strain out the whey, you might have a product that’s thinner than you hoped for, but it’ll still be yogurt. Experiment and enjoy! That’s what food preservation is all about!