It turned out fairly well. There are definitely things I think I can do to improve it, and from what I've read it really takes a lot of trial and error to make it just right. One thing I didn't realize when I made this batch is the importance of temperature. The recipe I used didn't say much about monitoring temperature, but further research suggests that is a key part of the process (so I will include it when I describe the recipe below).
Ingredients:
1/2 gallon whole organic milk
1/2 cup starter (yogurt with active cultures)
Notes on ingredients: Whole milk is not necessary, but will make a creamier yogurt. Many people say organic is a must, and some prefer non-homogenized. If possible, avoid ultra pasteurized milk (raw would be great if you can get it). For the starter, it is possible to find pure bacteria cultures, but the easiest method is to use some store-bought yogurt or previously made yogurt, as long as it has "active cultures." If using homemade yogurt as a starter, you'll have to go back to a store-bought starter every 4-5 batches or so... at least, that's what the experienced people say.
Instructions:
Pour milk in a clean crockpot and cook on low for 2 hours. (You need to heat the milk to 180F, at which point apparently there is some kind of change in its protein structure to allow for coagulation and also to kill off "bad" bacteria.)
Turn off crockpot and let it sit on your counter top, covered, for 3 hours. (To reduce the milk's temperature to 110-115F.)
After 3 hours (or once the milk has hit the proper temperature), add starter culture. Do not aggressively whisk or stir the yogurt starter into the milk - you want to mess with the milk as little as possible. I just added the starter, then used a whisk to gently swirl the yogurt in with about 2-3 circles. Some people recommend removing a cup of milk, swishing the starter into that, then pouring the whole thing back into the crockpot.
Once the starter has been introduced, wrap the covered crockpot in a big towel and let it sit on the counter for 8-10 hours. (Ideally, it should stay at 110-115F during this time. One fellow turned his crockpot on low or "keep warm" for 5-10 minutes a few times in order to maintain proper temperature. It will depend on the temperature of your kitchen and how well insulated your crockpot is.)
That should be it. Transfer your new yogurt to clean, sterilized jars and store in your refrigerator. I got 3 and a half pints of yogurt out of 1/2 gallon of milk.
There are all sorts of extras you can do to your yogurt, from adding vanilla and maple syrup or other flavors to letting it drain in cheesecloth for a thicker, Greek-style yogurt. (I tried the cheesecloth thing, but I must have used too many layers of cloth because my yogurt didn't drain at all.)
Since my husband enjoys taking strawberry yogurt to work in the morning, I'm testing these on him this week:
It's basically 1-2 tbsp of pureed organic strawberries (with a dash of sugar), then 4-5 tbsp of the yogurt. I anticipate having to tweak these to his tastes, but I'm hoping they work out because they are healthier and much cheaper than store-bought flavored yogurts. The next step will be getting our incredibly picky toddler to eat my yogurt - if it doesn't look right, he won't touch it.
If you like yogurt, give this a try - it really was sooo easy - and let me know how you do!