Check out this blog for detailed instructions, but here's how it works for me (so you can see how easy it really is):
5:00 Right about when I'm starting to make dinner, I pour 1/2 gallon of milk into the crockpot and turn it on low.
7:30 When I'm doing dishes after putting Baby to bed, I turn off the crockpot.
10:30 When I'm about to go to bed, I stir in 1/2 cup of yogurt (yep, plain regular yogurt) and cover the crock pot with a bath towel.
The next morning: I wake up to 2 quarts of delicious, creamy yogurt! Ladle it into some old yogurt containers and I'm all set.
See how easy that is? You don't need any special equipment or ingredients. I've been making yogurt for a couple months, and you don't even need to buy a new "starter" each time...just save 1/2 cup from your last batch. It will turn out a little bit more runny than store bought yogurt, but it's really not very different. I've read here that you can just add 1/2 cup of powdered milk at the beginning to thicken it up a bit. This blogger also recommended to add a spoonful of jam per bowl when you serve it for flavor.
It's nice knowing exactly what we're eating without worrying about too much sugar or artificial sweeteners. Baby loves this yogurt plain and I usually have it in a smoothie or with homemade granola (another easy treat!).
I'll let you do the math to see how much money you save with 5 minutes of hands-on effort: How does the price of 1/2 gallon of milk compare to two full quarts of yogurt? I felt like a criminal after discovering how amazingly easy this is and not sharing it with all of you, so
now I can sleep again :).