Yep, you read that correctly, you can make yogurt in your slow cooker. After reading several posts on making yogurt at home, including one of my favorite blogs, The Frugal Girl who does this on her stovetop instead of a Crockpot, I became intrigued with using the slow cooker method to make something I normally buy every week. I tried several variations with the crockpot, but this is what has worked most consistently for us:
Crockpot Vanilla Yogurt
8 cups of milk (we use 2%)
1/2 cup dry instant milk
1 cup sugar (omit if you are making plain yogurt)
1 Tbsp vanilla (omit if you are making plain yogurt)
2 Tbsp plain or vanilla yogurt as starter (must contain live cultures)
Put only the milk and the dry instant milk in the Crockpot and stir. Cover and heat on low for about 3 hours, until the temperature reaches 180 degrees (we are trying to kill other microbes that will compete with the yogurt starter bacteria that will turn the milk into yogurt). My Crockpot has a thermometer probe and I can program it to turn off at 180, but if yours does not you may just have to start checking it every 30 minutes once it has been on for 2 1/2-3 hours.
When it reaches 180 degrees, turn the unit off. Add 1 cup sugar and 1 Tbsp vanilla if you are making vanilla yogurt.
Keep the lid on and allow the milk to cool for about 3 1/2 hours, until the temperature is between 110 and 115 degrees. It is very important that the temperature be below 115 and above 105 to keep the environment right for the yogurt bacteria to do their thing.
Add in the “starter” yogurt. I highly recommend buying a good, name brand yogurt with no artificial sweeteners, such as Yoplait or Dannon, plain or vanilla flavored.
Cover with a towel or blanket to trap the heat in and then place the covered Crockpot in a draft-free area overnight, or 8-10 hours. I put my lidded crockery insert, covered with a bath towel that has been folded in half, in the oven with the light on overnight. If you used your oven to bake dinner, make sure to leave the door open and let the oven come to room temperature before inserting your crockery.
In the morning, I find half a gallon of thick, warm vanilla yogurt. We spoon it into storage containers and it keeps in the fridge for 7-10 days, or until we eat it all, which usually comes first. Don’t forget to keep 2 tbsp of your homemade yogurt in a separate little container in the fridge to use as the starter yogurt for your next batch! We eat it plain, topped with thawed or fresh berries, walnuts or granola. It is also very tasty in smoothies.
Obviously this takes a long time, with very little actual hands on time. I would recommend making it on a weekend if you work full-time during the week. I usually start yogurt between noon and 2pm to make sure there is plenty of time for it to heat up and then cool back down enough for me to put the starter in a get it towelled and in the oven without me having to stay up late (or it being late enough that I simply forget about it, which has happened and I had to trash 1/2 gallon of milk!). But, as with most things that require thought and effort, it is well worth it.