First, a yogurt starter. You can buy acidophilus yogurt starter at a store or you can just use regular yogurt, like I do. Just read the back to make sure it really does have live cultures.
Second, milk. I just used powdered milk and water, although it is thicker if you use whole milk. If you use store bought milk omit the water and change the powdered milk to 1/2 cup and add 1 quart of purchased milk.
3 3/4 cup warm water
1 3/4 cup instant dry milk powder
2-4 Tbs yogurt
In a pot combine warm water and powdered milk. Stir until combined. Turn heat on low-medium and stir occasionally until it reaches 180 degrees.
Remove from heat and let cool until it reaches 115 degrees. (This is important or else it will kill the good active cultures.) After it has cooled to 115, add the yogurt. Stir until disolved.
Meanwhile, preheat your oven to "warm".
Place yogurt mixture into a sterile container (a heavy non-metal material like glass works best) and place in oven. Turn oven off. Check the temperature periodically to keep it at about 100-115 degrees. (An oven thermometer is cheap if you don't have one).
Now all you do is let it sit in the warm dark oven for 5-8 hours (depending on how sour you like it). When it is thick, stir and place in the fridge until chilled. It will last for about two weeks.
That's it! Remember to keep a few tablespoons to use for your next batch. You can even freeze some in a ziplock bag or ice cube trays for when you're ready.
There's just something satisfactory about making your own yogurt. The first time I made it I was so excited... then I wondered what I was going to do with all this plain yogurt. The possibilities are endless! I even added 1/3 cup plain yogurt in place of milk and butter to my kids boxed macaroni and cheese. My kids love it mixed with applesauce. I like it on top of fruit with granola and honey. You can use it in place of buttermilk, sourmilk and sour cream in most recipes. Mix it with equal parts mayonaisse for a lighter and tangier flavor. Think of smoothies, jellos, dressings and popsicles.... don't worry, recipes will follow! Don't forget Brooke's Yogurt Yeast Rolls. Another idea is Yogurt Cheese.
Yogurt Cheese Recipe
Line a cheesecloth or coffee filter in a colander and place inside a bowl. The bottom of the colander should not touch the bowl. Pour yogurt into the cloth and place in fridge overnight. The whey will seperate from the yogurt and drain into the bowl leaving the yogurt very, very thick. You can now use this like cream cheese! 1 qt of yogurt makes about 1 1/2 cups of cheese.