Yogurt, Homemade, From Good Eats, Alton Brown - cooking recipe

Ingredients

1 quart 2% low-fat milk
1/2 cup non-fat powdered milk
2 tablespoons honey
1/2 cup plain yogurt, that contains active live cultures, at room temperature

Preparation

Place yogurt in a bowl and bring to room temperature.
Heat milk, dry milk and honey to 120 degrees; pour into a very clean container that will be used to make the yogurt.
It should cool back to 115 degrees.
Whisk 1 Cup hot milk into 1/2 Cup room temperature yogurt.
Add yogurt mixture back to warm milk.
Wrap container with a heating pad and set on low or medium low.
Be sure to have the pad wrapped around your container so that the heat is evenly distributed around the container.
Place inside a stock pot.
Monitor the temperature of the liquid, your target is 115 degrees (perfect temperature for fementing yogurt) and adjust heating pad accordingly.
If it gets above 120 degrees you'll kill the active cultures, so use a temp alarm if you have one!
You can also do this on the heating element of your electric coffee maker, but it doesn't provide the heat as evenly as the heating pad and must be insulated with an oven mitt to prevent overheating.
Allow to sit for 3-9 hrs depending on the consistency that you disire.
The longer it sits the firmer it gets.