This is simple. A few tablespoons of pre-made yogurt gives the necessary bacterial base while the milk makes up the bulk of the yogurt. I have listed whole milk as the starting point but you may use nonfat, low-fat, (unsweetened) soy milk, etc., and the formula remains the same.
Makes 1 quart of yogurt
- 1 quart whole milk
- 1/4 cup plain whole milk yogurt
Have a 1 quart jar with a screw-on lid (or several smaller jars) ready and boil water. Pour the boiling water into the jar and let it stand for 5 minutes to sterilize it. Pour out the water and set aside.
In a large, heavy-bottomed saucepan heat the milk until it reaches 180 degrees on a thermometer. Remove from heat, keeping the thermometer in the pot.
When the temperature drops to 115 degrees, stir in the yogurt until thoroughly incorporated. Pour the mixture into the jar and screw on the lid.
Place the yogurt in a warm place and leave it undisturbed for 10 to 12 hours. You can wrap the jar with a towel if your house is a bit cool. For a thicker, tangier yogurt, let yogurt sit an additional 3 to 5 hours.
Refrigerate yogurt for at least 3 hours before eating.