Make yogurt at night and leave in oven
1 packet yields 1/2 gallon of yogurt
Use whole milk
Heat to 185F
chill to 112F using ice bath.
Add culture at 112F.
Let sit 2 minutes.
Place in warm oven, then turn oven off and let sit for 12 hours
Add heavy cream
Yogurt culture can be kept in freezer
Put yogurt in ice cube trays to use a next batch
Use 1 generation in freezer, then start with new culture