ENVIRONMENT
03/21/2009 05:12 am ET Updated May 25, 2011

Make Your Own Yogurt (And Stop Wasting Soured Milk)

Changing our relationship to the earth requires re-evaluating every relationship in our lives. For example: old food.

Why does moldy bread, fermenting juice, or sour milk strike fear in our hearts? Are these things really so bad that they warrant the pinched nose fingertip dash to the trash can? Much of the old food we junk has value, either as compost, shoe polish, or different forms of perfectly delicious food. It's wasteful to just toss it out. For example, you know that swollen carton of milk that's been sitting in your fridge for suspiciously too long? ...The one you're afraid to sniff? Why not make it into yogurt? It's deliciously green. (The practice, not the milk.)

The following is an excerpt from When Technology Fails: A Manual for Self-Reliance, Sustainability, and Surviving the Long Emergency by Mathew Stein.

Fresh whole milk and cream spoil rapidly without refrigeration, but by adding cultures of "friendly" bacteria, you can control the way your milk sours. The result is yogurt, which will keep in a cool room for several days. You can start your yogurt with commercial cultures, three tablespoons of commercial yogurt containing "live cultures," or some of your last batch of homemade yogurt.

To make your own yogurt, take the following steps:

  1. Heat the milk to 150°F to pasteurize it (do not boil).
  2. Cool the milk to between 105°F and 110°F.
  3. Mix in 2 tablespoons of starter yogurt (buy it anywhere) per quart of milk. Add powdered milk if desired for added thickness.
  4. Cover and keep warm until thickened. On top of a refrigerator overnight is a good place to keep it warm. Wrap the container in thick towels if there is no warm place.
  5. Refrigerate.

Happy yogurting! Send pictures!