The sweet satisfaction of homemade yogurt
THE SIMPLE JOY OF HAVING BETTER FOR LESS
IF YOU LOVE YOGURT, making your own should be a culinary rite of passage, along the lines of baking your own bread or roasting a chicken, though easier than either.
Mere minutes of active time, and the payback is huge: a pot of tangy, silky yogurt, made with ingredients you can control and personalize to your tastes.
Yogurt basics
Yogurt is simply milk that has been mixed with specific types of good bacteria, then left to ferment. Goodquality, store-bought yogurt made without additives can be expensive — if you can even find it. Those who eat dairy may find some at farmers’ markets or in gourmet stores, but fine alternative yogurts are much harder to come by. Making your own guarantees a supply, and in time, you’ll make yogurt that’s better than the fancy brands for a lot less money.
To make your own, you’ll need good-quality milk (dairy or non) and your favourite plain yogurt. The dairy milk is heated to between 180 and 200 F (just under boiling) to denature, or unravel, its protein structure, allowing it to thicken when it meets the bacteria. (Nondairy milk is simply simmered here to activate the starch.) Then, in both cases, the milk must be cooled to 110 to 120 F before the bacteria (also called the starter culture) is added. This step is important: anything hotter than 130 F could hurt the bacteria; anything cooler won’t encourage its growth. Then the milk is set aside to ferment in a warm (ish) place for six to 24 hours, during which the good bacteria multiply, and the milk gains body and texture. Finally, the yogurt is refrigerated, to stop the fermentation while the yogurt thickens.
What’s a starter?
You can’t make yogurt without a starter culture, that is, specific types of friendly bacteria to activate the fermentation process.
The two bacteria most often used are Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus. Lactobacillus delbrueckii subsp. bulgaricus turns lactose into lactic acid, producing a sour or tangy flavour. Streptococcus thermophilus also breaks down lactose into an acid — a digestible fatty acid.
For dairy yogurt, the easiest starter culture is any plain live yogurt: look for the words live, living or alive in the ingredient list. You’ll also want to choose a starter yogurt without preservatives, but with a flavour you enjoy since you’ll taste it in your batch. You can use homemade dairy yogurt in the subsequent batches, but bear in mind that it’ll weaken over time. After a third or fourth use, it’s best to use a new starter culture. (Note: Homemade nondairy yogurt cannot be used as a starter culture.)
Yet another option is heirloom yogurt starter, available at some healthfood stores and online. The yogurt you make from these strains can be used as a starter indefinitely. Think of it as analogous to a sourdough starter for bread: just as you would in bread baking, you’ll have to use it frequently (at least once a week here) to keep it active. The first batch you make from an heirloom starter might turn out on the thin side, but should thicken in subsequent batches.
To culture nondairy yogurt, you can use commercial yogurt, probiotic powder or probiotic capsules, found at health-food stores or online. (If using capsules, choose refrigerated ones over those stored on the shelf.) You can also use a vegan yogurt starter, or if it doesn’t bother you, a dairy-based starter culture will work in a nondairy yogurt.
Picking a milk
You have several options for dairy milk, the most common, of course, being cow’s milk. You can start with creamline (nonhomogenized) or homogenized milk. Creamline will create a yellow layer that sits atop the yogurt, while homogenized is smooth throughout and won’t separate. For best results, choose pasteurized milk instead of sterilized or ultrapasteurized (UHT) milk. It tends to have a better flavour than ultrapasteurized, and ferments more willingly.
If you’d prefer to use sterilized or ultrapasteurized milk, you don’t need to heat it to 180 to 200 F. That was done before you bought it. Just heat it to 110 F, stir in the culture, and let it ferment.
Another variable is fat content. Fat adds creaminess and body, so the less fat a milk has, the thinner the resulting yogurt will be. (Higher-fat milks yield thicker, richer yogurts.) Our master recipe, which calls for whole milk, with the option of adding cream, yields a luscious yogurt, but you can substitute low-fat milk: 2 per cent works much better than 1 per cent, in terms of flavour and texture.
You can also make yogurt from goat’s, sheep’s or buffalo milk. Each has its own flavour. Goat’s milk, for example, is tangier than cow’s milk, and may need less time to ferment.
For these yogurts, you can use a cow’s milk starter, a starter of the same milk variety (if you can find it), or a storebought starter culture powder. Simply substitute the milks one-to-one for cow’s milk in our master recipe.
Lactose-free milk often won’t ferment and thicken properly. If you can’t tolerate lactose, use an alternative dairy-free milk instead.
Nondairy milks generally stay thin even after fermentation. They’re tangy like yogurt, but tend to be more pourable than spoonable. Thickening them, however, isn’t hard. Our master recipe uses agar powder, but you can experiment with gelatin, pectin, cornstarch, arrowroot or gums (locust bean or xanthan). Or enjoy them as they are in smoothies or poured over cereal.
After testing, we’ve found cashew milk yields the best results when used in nondairy yogurt. It’s rich, gently flavoured, and ferments willingly with either a yogurt starter culture or probiotic capsule. Almond milk also works, but unless it’s homemade, it stays very thin. Soy milk thickens without having to add starches or agar powder, giving you a lushly textured yogurt. Less successful is oat milk, which takes on a cardboardlike flavour when fermented.