Yogurt

Timeframe: 8 to 24 hours

Yogurt uses a thermophilic bacteria culture that needs a warm environment to come to life.

Ingredients

• 1 half pint active kefir or active yogurt culture
• 1 gallon whole milk

Supplies

• mason jars
• silicone spatula or wooden spoon
• 1 gallon pot or double boiler
• optional: infrared thermometer or candy thermometer

Method

1. Preheat the oven on warm (170°F) and place the starter culture out to acclimate to room temperature; turn off oven once it preheats.
2. Heat the milk till bubbles begin to form (180°F with thermometer). Stir frequently. Heating in a double boiler prevents scalding on the bottom of the pot.
3. Cool milk to 110°F, or the point where it feels hot, but it is not hard to keep your (clean!) finger in it. You can speed the cooling by placing the pot of milk in a larger pot of cold water.
4. Mix about 4 tbsp warm milk with 4 tbsp starter culture into each jar. Estimating is fine.
   
5. Fill jars with remaining milk, cap loosely with metal lids, and place in oven.
6. Check the yogurt after 8 hours. If it hasn’t thickened, preheat oven briefly till warmth is restored. It’s important not to cook the yogurt, the culture cannot survive beyond 130°F! Leave it another 4-8 hours. 
7. Refrigerate and enjoy. Reserve a half pint for use as the next starter culture.

Greek Yogurt

Follow steps for Kefir Cheese.

Boiling milk causes its proteins to coagulate (imagine a ball of tangled yarn), which gives yogurt its thick consistency.

If you prefer yogurt in a more fluid form, simply use 110°F as the top temperature when heating the milk.

How to Clean Milk Scalded to a Pot

If scalded residue adheres to your pot after heating milk for yogurt, try one of these easy techniques for cleaning.

1. Pour equal parts vinegar and water to cover the bottom surface of the pot and let rest overnight, then scrub clean with a sponge. 
2. Or, bring a small amount of water to a boil and add baking soda. Turn the heat down and let boil for several minutes, ensuring the bubbles don't overflow. Drain, rinse, and scrub clean with a sponge.