I make yogurt weekly from our raw goat milk. Here is how I make it:
Put a half gallon of milk into a pot. Put an inch or so of hot water into a larger pot and set on the stove, high heat. Set the pot of milk in the larger pot to create a double boiler. Stir the milk and measure the temperature until you get to 113 F, then remove from heat. Put a scant 1/8 tsp of yogurt culture (ABY-2C) into the bottom of a Yogourmet yogurt maker container, pour in the warm milk, stir, and snap on the lid. Plug in the Yogourmet heating unit, add warm water to the upper line, insert the container of warm milk, and put on the outer lid. Leave it for 24 hrs, then put the yogurt in the fridge and leave it sit undisturbed at least 12 hrs. Then, when using it, skim yogurt off in layers rather than digging a big hole in it. This helps to keep the whey from separating. This yogurt will be more runny than what you buy in the store because commercial yogurt is thickened with dry milk or gelatin.
To sweeten my yogurt, I thaw and mash our blackberries and add some of our applesauce for a 100% homegrown and sugar-free health food. I eat it every morning.
I got my Yogourmet yogurt maker from Amazon.com
I get my ABY-2C culture from GetCulture.com.
I have also used Yogourmet culture from Amazon.com. The last time I used this culture, I was able to restart my new yogurt from my existing yogurt about 5 times in a row before it got too yeasty and I had to start it over. I would use 6 tablespoons of yogurt from the bottom of the container to start the new batch. I have not had as much success in doing this with the ABY-2C culture.
I have heard of others having success using Trader Joe's Greek style yogurt or Strauss yogurt as starter. Nancy’s yogurt did not work well for me as a starter. Sundance also sells yogurt starter under their salad bar but I have not tried that brand.