My devotion to dairy began at an early age—a given, perhaps, since I grew up in Vermont. As soon as I could wield a knife, I would carve slabs of cheddar from the Cabot block that was a staple in our fridge. Cream cheese was a favorite dip, spread, or snack (yes, eaten out of the carton with a spoon). Butter was fantastic and paired excellently with cream cheese; who knew?
So I guess it’s not surprising that, when I had my cholesterol checked for the first time at age 10, it was through the roof. Since I was otherwise healthy and rail-thin, the doctor ordered my mother to limit high-cholesterol items in my diet. Out went the chunks of cheese, pints of ice cream, and blocks of cream cheese. In came nonfat milk and probably the most healthful form of dairy, plain yogurt.
Making yogurt has since become a favorite weekly ritual for me. My dependence has switched recently from the rather thin kind that I grew up on to the thicker, creamier Greek-style variety, which is strained for a thicker consistency and richer flavor.
There are good reasons to make your own yogurt. First, it’s easy. Second, quality pints of the stuff don’t run cheap. But perhaps most important, many of the brands on the market take shortcuts. Instead of using an expensive separator to press out the whey, they opt for the cheaper method of mixing in milk proteins, pectin, or gelatin to boost the percentage of milk solids. And some brands include inulin, a flavorless dietary fiber that absorbs liquid. So instead of worrying about additives, thin texture, or sour flavors, just make your own.
Over the years I’ve used all kinds of different brands of store-bought yogurt as starters. Some resulted in thin, tart, or downright sour yogurt, while others were mild, milky-tasting, and creamy, which is what I prefer.
My advice? Use the best-quality milk and yogurt that you can find for this recipe; be sure that the “starter” yogurt contains the live active cultures Str. thermophilus (ST) and Lb. bulgaricus (LB); and don’t forget to save some of this batch of yogurt for starting your next batch.
Making yogurt from milk requires a starter of plain yogurt, which must contain live active cultures in order to work. (Freeze-dried starters such as yógourmet also work but the flavor is too tangy for me.) I found a lot of existing recipes that use an 8:1 ratio of milk to starter yogurt, which works well. I tried using lesser amounts with some success, but it took longer to ferment and didn’t always set up right. I always start with the best-quality milk and yogurt I can find.
First, heat the milk in a saucepan to between 170 and 180 degrees, stirring occasionally. This alters the milk proteins so that they will create a creamy, viscous texture instead of separating into curds and whey. The milk begins to steam when it’s at the correct temperature; stir in the dry milk powder (which helps thicken the yogurt) when it reaches this stage.
After the milk is heated, cool it to around 110 degrees—too hot and it can destroy the friendly bacteria in the starter. To speed up the process, transfer the milk to a bowl set over an ice bath. Stir the milk occasionally so that it cools faster and more evenly.
When the milk is cooled to about 110 degrees, it will feel warm but not hot to the touch (similar to warm water when proofing yeast).
Instead of adding the starter yogurt directly to the cooled milk, I like to thin it first with a little of the milk, which will make it easier to incorporate. Ladle a little of the cooled milk into the starter yogurt, and whisk until smooth. Then transfer this thinned starter into the bowl with the milk, whisking to combine.
After introducing the starter to the milk, cover the bowl with plastic wrap and pierce several holes in the top to allow the yogurt to breathe.
Next, place the bowl in a warm environment to ferment. The bacteria like a 90 to 100-degree temperature. Fortunately, at work in the test kitchen I can set an oven to 90 or 100 degrees exactly, but when I’m at home I use my gas oven and a thermometer to maintain the temperature. Turning the heat on for a minute warms the inside of the oven just enough. Every hour or so I check and turn the oven on briefly to rewarm if needed. (The pilot light in my old oven kept things around 90 degrees and I didn’t have to fuss with the temperature. It also made it easy to leave the yogurt overnight.)
Depending on what type of starter you’ve used, the bacteria can take anywhere from 5 to 8 hours to transform the milk into yogurt. Usually I leave the batch alone for about 7 hours, and then start checking for doneness. (Yogurt doesn’t like to be disturbed, so I try not to jiggle the bowl too much when doing this.) When it’s ready the yogurt will appear thickened, creamy, and set. Sometimes there is a little liquid in the bowl after fermentation, which is normal. It’s simply the separated whey; whisk it together to recombine.
At this point the consistency of the yogurt is super smooth and creamy but a little thin. Since I like not only a thicker texture but also a richer flavor (almost like yogurt cheese), I typically strain my homemade yogurt to mimic Greek-style.
To strain the yogurt, set a mesh strainer over a large liquid measuring cup (or bowl) and line it with a couple of coffee filters or a double layer of cheesecloth. After pouring the yogurt into the strainer, cover it with plastic wrap and refrigerate overnight. The whey begins to drip down almost immediately.
In the morning about 2 cups of whey have been exuded. If you want a less thick and rich yogurt, simply let it drain for less time.
After straining, you’ll have about 2 cups of delightfully rich and creamy yogurt.
Honey is my go-to sweetener for yogurt, with raw sugar coming in a close second. A handful of fresh berries, and I’m ready to start my day.