Step 1: Pour 1/2 gallon of milk into the Crock Pot and cook for 3 hrs on low setting, or until the mixture reaches a temperature of between 150-175 degrees.

Step 2: Ladle 1/2 to 1 cup of heated milk into a bowl and add gelatin, 1 tsp at a time, whisking constantly so that no clumps form. Return milk-gelatin mixture back to Crock Pot and give it a good whisk (If you mixed them gradually, you shouldn't have clumps; but, if you do, use a fine mesh strainer to pour the milk-gelatin mixture back in to remove clumps).

Step 3: Turn Crock Pot off and allow the milk to rest for 2-3 hrs, until the mixture cools to around 110 degrees (if milk is 115 degrees or above, bacteria in the starter can be damaged).

Step 4: Ladle 1/2 to 1 cup of milk from the Crock Pot into a small bowl and whisk in the yogurt starter. Add this mixture back into the Crock Pot and give it a few gentle stirs. Cover the entire Crock Pot (still turned off) with a couple of large towels or a large blanket, and allow to incubate for 8-12 hours.* (The longer the incubation, the higher the acidity and the more tart the yogurt - I usually incubate for 10-11 hours)

* I have read from others online that, if the ambient temperature is below 70 degrees or so, it's very hard for the cultures to work during Step 4. If your home is cooler than 70, consider placing an inexpensive painter's light or heat lamp nearby.

Step 5: Remove about 6oz of the plain yogurt and reserve as a starter for your next batch. Add ingredients for vanilla flavoring if desired. Yogurt will continue to firm up once refrigerated and will keep for a couple of weeks.