Notes: There are many methods for making yogurt, as well as yogurt-making machines. After several years of experimentation, this is the one I settled on, but feel free to play around.
Yogurt culture is available at most natural food stores. Store-bought plain yogurt or the dregs of your last batch also can be used, although the bacteria can lose potency after several uses.
1 gallon fresh cows or goats milk
1 packet yogurt culture or 1 cup plain yogurt
Heat milk to 180 F, remove from burner and cool to 112-114 F. (I do this by pouring it in a jar and placing it in the sink with cool water and ice.)
Add yogurt starter and stir. To ferment, I place it in a cooler next to a jar of hot water with a towel wrapped around both. This helps keep the bacteria in the proper temperature range. Others use their ovens at low, low temperature.
Close cooler and let sit for about 12 hours.
For thicker, Greek-style yogurt, strain by ladling into a cheesecloth-lined strainer (You also can buy strainers specifically designed for this purpose.)
See Chèvre recipe for some suggested uses of the leftover whey.
Recipe courtesy of Katie Burford.