You will need a 2 quart saucepan, 2 quart jars and some way to keep your yogurt warm for about 4 - 6 hours and 2 tbsp. of live culture yogurt...check on the container....it will say live culture yogure.. After you make your own, you'll not have to purchase it again....you'll have your own live culture.
Warm 2 quarts of milk (I use 2%) to 180 degrees.
Then set if off the burner and allow to cool to 115 degrees. At this point, stir in 2 tbsp. of live culture yogurt. Maintain your yogurt now at 110 degrees for the next 4 - 6 hours.
This can be done several ways: in your oven, on the very lowest setting, in a bath of warm water (to help the heat from varying too much)-and some people report being able to achieve 110°F with just the warm bath and the oven light on-or in a very well-insulated cooler.
Another method I tried this time was to use my slow cooker. I put the jars in, added warm water to about half way up on the jars, and chose the “Keep Warm” setting. After I had stirred in the starter yogurt, I poured the mixture in to two quart jars. I monitored the temp for the next 4 hours and would sometimes have to turn the cooker off so as not to get too hot.
Pour hot water (115°F) into a cooler, put your jars of almost-yogurt in there, and shut the lid, checking every now and then that the internal temperature is still 110°F or so, and replace the warm water as necessary. No matter which method you choose, take care to keep the temperature as close to 110°F as possible.
Your yogurt is done when it's firmed up (though it'll come together a bit more as it cools). Once done, refrigerate your new yogurt and enjoy, ad nauseum. Stir in granola or oats and allow to sit a spell. Add fresh fruit just before you eat it or, for maximum freshness, and rejoice that you'll never have to buy yogurt at the store again.