I made homemade yogurt for the first time today (without a yogurt maker).
Wow, so easy. There are a lot of ways to do it, but I chose one of the simplest (no double boiler).
I heated the milk slowly to 185, stirring frequently. Then cooled it on the counter until the temperature was about 110 degrees and then added in a couple tablespoons of plain yogurt containing live cultures (I chose Chobani greek). Poured the yogurt into a crock pot (because I was going to need the dutch oven that I heated the milk in) and put the crockpot on a heating pad set on med. and covered with bath towels, and let sit for 5.5 hours (the recipe said 3.5 to 12 hours - and the longer incubation, the tarter the yogurt).
The half-gallon of milk made half-gallon (two quarts) of yogurt. If I want a thicker greek-style yogurt, I can strain it and will (per the recipe) end up with 1 to 1.5 quarts of strained yogurt.
At 1.50 for the milk (and almost nothing for the yogurt - especially since I can use my homemade yogurt as starter for the next batch), that's a pretty good savings.
And it tastes better than the best yogurt I've ever eaten (and not just because I made it. I've never had yogurt this mild and milky tasting. There is some tartness, but it's very subtle. I love that. It reminds me more of creme freche.
And along the way, I found recipes for sour cream and various cheeses that are nearly as simple.
Maybe I'll start some sprouts tonight too, just to get into the hippy spirit.