1/2 gallon whole milk
1/4 cup plain yogurt or yogurt culture
Bring the milk to a simmer, or scalding as Grandma use to say, 185 degrees if you’re keeping track. This heating makes for thicker yogurt by denaturing the proteins.* Let the milk cool to around 117 degrees. Over 120 will kill the culture, under 108 will slow down the process. Add the culture blended with a little cool milk. Pour the mixture into clean glass jars, leaving a little headroom for mix-ins later.
Fill your crockpot vessel with warm water that’s around 112 degrees. You can also heat the water in the crockpot, but I found that warm tap water is quicker. Load your crockpot up with jars. Mine easily fit 8, 1/2 pints and 5, 1/4 pint jars with lids. Check the temp after it’s loaded and adjust with warm or cold water as needed. I just leave a thermometer in the pot. Put the lid on and wrap your TURNED OFF and/or UNPLUGGED crockpot in a fluffy towel for 4-6 hours.* Refrigerate your yogurt for several hours and you’re ready to go.
You can leave your yogurt in the crockpot for longer, but this does tend to produce a more sour product. You can also use lowfat or nonfat milk, but it won’t be as thick and it will taste very sour. For a real treat, try making a version with cream or half and half. Can I say dessert?
*In the mistake department on my second batch of this yogurt, I accidentally left my crockpot on low for several hours with my yogurt starter in it. (I thought it was off!) While no actual harm was done to the milk, and I had to add more yogurt starter, it made for weirdly slimy, viscus yogurt. Edible, but not that pleasant. So do your self a favor and unplug the crockpot!