Ingredients
1 gallon of milk, any kind (though goat milk tends to be runnier)
2 tsp starter yogurt (with lactobacillus bulgaricus and streptococcus thermophilus, check your label!)
Equipment
crockpot
thermometer
measuring cup
measuring spoons
bath towel
small cereal bowl
optional large catch bowl
optional clothespins
optional colander
optional muslin, cheesecloth, or kitchen towel
Start by putting a gallon of milk into your crockpot, put the lid on, and turn the temperature on high. Go and watch a couple episodes of Extreme Cheapskates (oh.my.god.) and come back when the temperature reaches 180-190 degrees. If there is a little skin on the milk, just peel it off with a fork. Turn off the heat and let the temperature come back down to 110 degrees. This is the perfect temperature to allow the bacteria to flourish and create the yogurt. Usually it takes two hours or so to come back down to temp.
When the temperature reaches 110, take out one cup of the heated milk and put it in a small bowl. Add two tablespoons of yogurt. I used two tablespoons of yogurt out of the penguin's moo-tube the first time I made this. Whisk the yogurt and the milk together very well, and then add the cup of milk back. Take your whisk and do side to side rather than circular stirs so the milk doesn't get too disturbed.
Put the lid back on the crock and move it to the oven. Wrap the crock in a bath towel and turn on the oven light, and let that baby cook overnight for 10-12 hours.
Pull the crock out of the oven the next day, and revel in your yogurt! You can stop at this point, and eat the yogurt as is. There should be a layer of liquid whey on top, which you can keep if you prefer runnier yogurt. But if you are like me and prefer a thicker yogurt, you have just one more step.
I put a muslin cloth over a colander and fastened it with clothespins, and put the colander over a catch bowl. Carefully pour the yogurt over the muslin and watch the whey drain off. I personally like to let it drain for two hours for max thickness.
Something like that.
After the whey drains, scoop the yogurt out of the bowl with a spoon and put it in a container for the refrigerator.
I like to add a little bit of honey and some preserves to the yogurt to flavor and sweeten it up some. Today I got a little fancy and added some diced strawberries. The yogurt should keep for 10-12 days in your refrigerator, but it usually gets wolfed down in three days at our house.
Boom.
(Note: Don't throw away the whey you drain off the yogurt! There are a lot of uses for it. Make some ricotta cheese, water it down and feed your plants with it, put it in a smoothie for some high protein power, and several etc. other uses for this super liquid!)