3 1/2 cups whole milk, plus 1/4 cup non-fat powdered milk – the powdered milk helps the yogurt to be thicker. This is especially important if you use low fat milk.
2-3 tablespoons plain unsweetened store bought yogurt, or yogurt left from your last batch.
Let the store bought yogurt sit at room temperature while –
warm the milk slowly to 180 degrees and then remove from heat and let cool to 110 degrees. Stir frequently while warming so it doesn’t scorch. Don’t microwave it!
Stir a little of the 110 degree milk into the store bought yogurt, and then add that mix to the rest of the milk.
Set in a bowl, cover with a towel, and place in a warm spot undisturbed for 12 hours. Chill.
UPDATE Feb. 3, 2018: Now I use a thermal lunch pail that holds 2 quart jars to incubate the yogurt. Fill one jar with boiling hot water and set it in the lunch pail along with another jar holding the yogurt mix. Keep in lunch container 4 hours and then check the yogurt. If the yogurt is thick, remove it. If not, rewarm the water and return everything to the lunch pail and let set until yogurt is thick. The longer it sets, the more sour it will become. I generally leave it incubating for about 4-6 hours, just until it is thickened. Put jar of yogurt in refrigerator to chill.
This recipe will make 1 quart of yogurt.
You can make yogurt with all non-fat powdered milk, but it may be thin. You can do this to thicken it up a bit:
Pour yogurt into a plain, clean, flour sack type towel, paper towel or large basket shape coffee filter and strain it for awhile over a large bowl. This will take out the excess moisture. Also, if you let it strain for a longer time, you have yogurt cheese, which is like cream cheese.
The yogurt you have made is plain, unsweetened yogurt. You can keep 2 tablespoons aside (frozen) for your next batch, but everything I read said to get some fresh store bought every few recipes. You can add some sweetening and vanilla to it if you like. Add fruits and/or granola and enjoy!