A reader asked how to make yogurt. It just so happened I had some pictures of the process but never got around to posting them. So...here goes.
Start with two quarts of milk. I like to use skim milk.
Add 1/4 cup of nonfat dry milk. This will add to the creaminess of the yogurt. Mix thoroughly and slowly heat the milk to 180F.
Don't stir during this time, just let the milk gently heat. When it hits 180F, turn the heat off and let it cool to between 105F and 115F. Again, don't stir. When the milk is cooled, there will be a thick nasty skin on top. Scoop this off and discard.
I like to use Bulgarian yogurt starter. I order mine from the New England Cheesemaking Supply Company. The reason I use Bulgarian starter is because it can recultured indefinitely.
Whatever you do, do NOT add the yogurt culture to the milk when it's hotter than 115F because it will kill the culture (been there, done that). Stir gently until the culture is thoroughly mixed.
Now the milk has to be incubated for a minimum of 5 to 6 hours (I usually incubate mine about 12 hours because I like a tarter yogurt). Anything can be used as long as the milk stays warm. Several years ago I bit the bullet and bought a Yogotherm Yogurt Maker. The reason I like this is it's nonelectric - it's literally just a plastic bucket that nestles inside a Styrofoam sleeve. You could probably put the milk behind the woodstove in order to stay warm; or inside a gas oven with a pilot light; or wrapped in towels and tucked inside a small ice chest. Use your creativity to come up with some way to keep the milk warm.
After the yogurt has incubated for several hours, remove the plastic bucket from the incubator and refrigerate overnight (or about 12 hours).
Before flavoring the yogurt, scoop out a few ounces and put it in a small container. Keep this in the fridge. This is your starter for the next batch.
To sweeten the yogurt, I use one cup of sugar or Splenda, then either add 1/4 cup vanilla (for vanilla yogurt) or some peach purree (peaches are my favorite fruit). Obviously you can flavor it however you like and to your taste.