My mom's recipe - you start with plain, store bought yogurt, and make more! PLEASE NOTE: If you substitute 4 c. skim milk for the 2% and powdered listed, the yogurt will come out somewhat runny. Prep time does not include sitting 6-8 hours.
YOGURT MUST HAVE ACTIVE ACIDOPHOLUS CULTURES. I recommend Dannon Plain, you cannot use a mixed yogurt or a "lite" yogurt.
Mix yogurt well with 2% milk, powdered milk, hot tap water, and sugar.
Let set without stirring for 6-8 hrs at about 90 degrees F. On old-fashioned gas stoves, we left it on top of the pilot light on the stove overnight. Today I turn on my oven for about a minute until it's really warm but not too hot to stick your hand inside. Then I put in the bowl, and leave it overnight.
If it still is not set, there are a few possibilities: 1) Did you use the right kind of yogurt "starter"? The yogurts that say in the ingredients they have gelatin do not work well. 2) Did you use 2% milk as listed, or all skim? If so, it will not set very firm but will still taste like yogurt. 3) Your spot may have not been warm enough. If yogurt is not "set" then just leave it alone until it IS set.
When you dish it out, there will be whey that accumulates in the "spooned out" place later- just dump it.
Save 1/2 cup of this yogurt for your next starter.