Anyone can make yogurt. No fancy machines are needed! Just a couple of pots and some milk. Homemade yogurt saves you money, since it's just the cost of the milk. We used to spend $5 a quart on yogurt, but now we spend $1.75 for twice as much!
Here we go:
Now it needs a warm resting place in order to become yogurt. If you have an older gas oven, it may have a pilot light that keeps it warm when the oven isn't on. Stick the small pot in there, covered with the lid. (If you're like me, stick a post-it on top of the oven knobs so you don't turn the oven on while it's in there!) You may not have a pilot light, but your oven light will keep it toasty enough. Set the covered pot in there with the light on. My light burned out after 2 1/2 years, though, and we can't figure out how to get the special cover off it. In the winter, I set the pot by the wood stove. You could also put it in a cooler with a jar of boiling water.
Without a pilot light, oven light, large enough cooler or woodstove heat (it's May), I came up with a simple incubation trick. Put the small pot back inside the large one, and put some very hot tap water in the big pot. Then insulate it with a towel:
Scoop the yogurt into a container. Your hands will get messy, since there's no easy way to scrape it off the towel! And now you have whey as well as yogurt. Simple!
~ I use pasteurized milk from a nearby dairy. It's gently pasteurized, not ultra pasteurized. Don't waste time and money trying to culture ultra-pasteurized milk! It won't work! Sadly, most organic milk in stores are this type. Try to find nice local milk instead. Raw milk is much easier and healthier for yogurt, but we only use ours for drinking. The six of us drink a lot of milk, and we save money by using cheaper pasteurized for yogurt and all our cooking. It's $1.75 to buy this milk at the dairy, but $2.50 for the raw.
~ I don't do all the extra work of sterilizing all the equipment, because I've read in many fermenting books that it's not necessary. It's actually better to use very clean but not sterile equipment. I make sure it's all clean, either washed in hot, soapy water or the dishwasher.
~ Take the spoonful of starter out when you make the yogurt, instead of using the last bits from your jar. When you've had spoons in there, scooping out servings all week, the cultures can be damaged. BUT don't despair if you forget! I've made plenty of batches from the last bits, when I forget.
~ If you make a batch and it stays milk after hours and hours, don't give up. Just stir some store-bought yogurt into the warm milk, incubate again, and it'll work. Your starter will sometimes get old or contaminated, and stop working. Mine tend to last months, or even over a year.
~ Feel the sides of the large pot while it's incubating to make sure it's still pretty warm. If it gets more lukewarm, just boil some water (a cup or two) and quickly pour it in to warm things up in there.