Canning jars and lids** (see note at bottom)
Candy/frying thermometer (optional)
Per quart jar of yogurt:
4 cups milk (whole milk is best)**
3 Tbs dry milk powder (optional, but it makes for a thicker yogurt)
2 Tbs plain yogurt
For 3 quarts of yogurt + one 1/2 pint jar (for starter)**:
3 quarts whole milk
1/2 cup (slightly heaping) dry milk powder
1/3 cup, heaping, (or 6 Tbs) plain yogurt
In a saucepot, stir together milk and dry milk powder. If you are using a thermometer, attach it to the side of the pan and bring milk to 185°F-200°F, stirring often. If you are not using a thermometer, bring milk just barely to a boil and then remove from heat immediately. If the milk has developed a foam on top, skim this off.
Fill a clean sink with about 2-3 inches of ice water (just make sure that the water level is low enough that when you add the pan of milk, it comes about halfway up pan). Set pan of hot milk into the ice water bath. Let milk cool to about 110°F (without a thermometer: baby-bottle warm), stirring often. This should take about 10 mins. If you leave your milk too long, and it gets too cool, just reheat slightly on the stove until it reaches 110°F.
While milk is cooling, boil some water (about 2 quarts if you are making 3 quarts of yogurt) and pour it into clean jars. Top with lids. Place in a towel-lined cooler. If you are making a lot of yogurt and using a large cooler, you can also just put a pan of just boiled water in the bottom of the towel-lined cooler.
Remove milk from cold water bath, and gently stir in yogurt. Pour into sterile glass jars.** Top with lids and screw top rings. Place jars of milk in the cooler with the hot water jars. Wrap towel around tops of jars and close cooler.
Let incubate for 8-12 hours. Do not open cooler during this time. You need to maintain a temperature between 98°F and 113°F. If the temperature is too low, the yogurt will not reproduce and you will have a runny final product. Temperatures over 118°F will kill the yogurt culture.
Remove yogurt jars from the cooler and place in the refrigerator to chill. Do not open jars or shake or stir yogurt until well chilled.
**NOTE: When I make yogurt, I like to make an additional jar (a small half-pint jar) to save as starter for the next batch. Using the full amount of milk given above will give you enough extra for this small jar. If you are not going to make an additional small jar, then reduce the milk by a few tablespoons per quart.
Serve with Homemade Granola