8 cups whole milk (NOT ultra pasteurized)
Step 1: Pour 8 cups milk into crock-pot. Cook on LOW, covered, for 2 1/2 hours.
Step 2: Turn crock-pot off, leave lid on. Leave alone for 3 hours.
Step 3: Remove 1-2 cups of warm milk from crock-pot and mix in 1/4 cup of yogurt.
Step 4: Stir milk/yogurt mix back into crock-pot.
Step 5: Put lid back on the crock-pot, then cover with a heavy towel to insulate remaining heat. Leave overnight.
Store your homemade yogurt in refrigerator and enjoy when cool!
Remember, this is plain yogurt, not sweetened. Add fruit and honey or a bit of sugar to sweeten to taste. It will be a bit thinner than store-bought yogurt, but you'll be so happy about all the money you're saving, you won't mind!
ETA: If you strain off the whey using cheesecloth, you'll have thick yogurt. Delicious!!