No expensive yogurt maker needed, no pain in the neck coolers packed with jars of hot water, etc.
You will need:
1-2 thermos jars, preferably with stainless steel liners, with enough volume to hold just over a quart of liquid. I got mine at tag sales for $1 each.
1 quart of milk--whole, 2%, skim, goat, whatever. I recommend using pasteurized milk, because you're going to provide an environment favorable to bacteria, but if you feel strongly about raw milk, use it. I'd go without before I'd drink it, but that's me--do what you want.
1/3 to 2/3 c. powdered milk-not necessary, but it thickens and enriches the yogurt.
1/4 c. PLAIN active culture yogurt-I used Stonyfield cow milk yogurt (not soy).
Sugar, honey, agave nectar, or sweetener of choice (if desired)
mixing bowl, spoon and thermometer
Most directions say to bring your milk to 180 degrees and let it cool, to kill any wild bacteria or yeast that may be living in the milk. You can do that if you want, I use the microwave. I did it that way the first few times, and find that it didn't make any difference. I'm much more willing to waste a possible odd-tasting batch of yogurt if a wild yeast or bacteria takes hold of a batch, than spend a lot of time at something that seems to me fairly unlikely.
Wash your thermos jugs thoroughly and fill them with extremely hot tap water, and leave them filled till ready to use. You're prewarming them to make a comfy incubator for your baby bacteria. Like a petri dish of warm milk!
I heat the milk in the microwave till it's 120 degrees, Fahrenheit. Stir, temp again--stirring can change the temp of the liquid 10 degrees. If you overheat-no problem, just let it cool to about 120 degrees, a little under is okay.
Stir in the powdered milk, and any sweetener you desire. Take the temp again, you want it to be at least 112 degrees by this point, if your starter is too cool for your baby Lactobacillus and Streptococcus. Add your starter, and stir well, so there are no chunky bits, it should be perfectly smooth. I add more like 1/3 of a cup of powdered milk for full-fat yogurt, and more like 2/3 for nonfat or lowfat. You can also stir in protein powders for higher protein yogurt, but they're gritty and I hate that, but I know lots of people who like it, and it thickens the yogurt a little. Whey protein tastes better than soy for this use.
Pour the water out of your thermos(es) and dry a little, no need to get carried away. Add the milk/yogurt mixure, leaving a little head room in the container, and cap them. Place in a warm spot for 12-24 hours. Try not to look at your baby bacteria to see if they're getting it on in the milk every five minutes, you lose some heat that way. Taste your yogurt after 12 hours, if it's not quite thick and not quite tart enough, check every 4-6 hours till you get the taste you want. It will NOT be as thick as grocery store yogurt, which has gelatin and gums. Don't worry, it will taste much better than storebought, and if you want it thick, strain it.
When the taste of the yogurt is to your liking, pour out of the thermos and refrigerate. You can eat as-is, add fruit or whatever, or strain to make Greek-style yogurt. To do that, line a colander (I prefer the wire mesh type for this) with muslin or very fine cheesecloth, and dump your yogurt into the lined colander. I do this in the sink, you could certainly do it in a bowl and retain the whey for food for humans or animals, it's nutritious. Fold the tops of the fabric over the cheese, place a plate or whathaveyou on top, and a light weight (I use a 15 oz can of something). Allow to drain for several hours, checking texture and taste occasionally. When it achieves the thickness you desire, spoon it into a container and refrigerate.
Easy peasy lemon squeezy. Remember that it will not have the texture of grocery store yogurt, but after it's strained it'll be very close. It's way fresher tasting, and better for cooking, it just acts better--less clumpy and weird. I never noticed the strong artificial taste and unpleasant slobbery texture of commercial yogurt till I started making my own.
Note: I've been known to use a seed germination mat to keep the yogurt mixture warm and happy during the winter. It works really well, so does a heating pad on the low setting.
Making Yogurt At Home
