Making yogurt is So Easy. I don’t care if you want to call me a hippy. Or if you think only post-feminist eco-housewives with too much time on their hands make their own yogurt. I swear that if you try this just once, you will become a convert. Maybe my fourth or fifth batch is on the stove as I type, and my method is failproof and is largely adapted from various recipes I found online. What you will need: a candy thermometer, a big pot (some people have declared that a double boiler works better, however I only used that method once and I just made an even bigger mess, although it also worked fine), milk and a few tablespoons of plain yogurt (preferably small batch and/or local and/or organic, etc. I started with Narragansett, but I’ve read Stonyfield Farms is another good one.)
I use whole milk – I tried this with low fat and it worked fine, but the yogurt was a bit thinner than I wanted so I switched back to the full fat kind. And I should also mention – although this should be obvious – that everything should be clean and sterile. But other than those two caveats, just jump right in and make your own batch!
First, over medium to low heat, warm the mik to 185 degrees. (This might take 5 – 10 minutes, perhaps stir it a few times and skim off any film that forms on top.) Then, cool the milk to 120 degrees. Don’t let it cool below 90 degrees or something scientific that is supposed to happen won’t – thus you must keep an eye on it. I.e. don’t put it in the fridge and forget about it. When it reaches between 110 – 120 degrees add in about two tablespoons of plain yogurt and stir.
Next you must keep it warm for 5 – 8 hours. I found a number of useful tips on how to best do this: a purchased yogurt warmer would do the trick. But who wants to spend $50 on a glorified hot plate? If you have an oven with a pilot light that is always on you can keep it in there. I generally have poured the milk into a metal bowl (conducts heat better) before cooling and have covered it with foil and wrapped it in a towel or two and allowed it to rest in either a cooler or the microwave. Both are insulted and keep heat in quite nicely. I have added a pitcher of boiling water to the cooler to help ensure that it stayed hot, but I am not sure if it is neccesary – depends on your cooler, I guess. You want as little extra space in either one as possible.
After about 5 hours or so the yogurt should be thick. A little green liquid on top is fine, just pour it off or stir it in. Transfer to smaller containers if you’d like or maybe flavor it with jam or maple syrup and toss it in the fridge. It should keep for at least a week – although I have kept it for as long as two weeks and it hasn’t seemed to go bad. Remember to keep a few extra tablespoons for your next batch though!
Active time: maybe 5 minutes, plus time watching the milk both heat up and cool down.
Cost: $3 for a half gallon of local milk = $3 for a half gallon of local yogurt