I came across a recipe for slow cooker yogurt well over a year ago but didn't think much of it. I like having yogurt for breakfast with cereal mixed in, especially in the summer with fresh berries. But finding a yogurt I can feel good about eating that is affordable is difficult. So I decided to give making it a try.
Most yogurts out there are made with milk (loaded with hormones), thickeners, artificial flavors and added sugars. The yogurt I made contained milk (local and sustainably raised) and active live cultures. You will need a half gallon of milk and half a cup plain yogurt with live active cultures. I bought a large container because it was the only size organic plain yogurt with live cultures that I could find. Since I wanted to make pure yogurt I wanted to use a starter without other crap in it.
I looked at many recipes and here is a compilation of a few that I think give the best directions. I have now made it three times successfully this way. Put the milk in the slow cooker on low and cook for 2.5 hours or until it reaches 180 degrees. I check on it every now again, mix it and take the temp because you want to make sure it does not boil. You want to kill off any bacteria so the live cultures can do their thing but if you get it too hot then the live cultures won't be able to thrive.
Then unplug the the crock pot and allow the milk to cool for 2-3 hours. You want the milk to be between 110-120 degrees but I think between 110-115 is best. When cool in a seperate bowl whisk 2 cups of the milk with the starter. Then pour back into the slower cooker and mix.
Put the lid back on and wrap it up with a thick towel or two to incubate. Leave it for 8 hours. I normally make it so that the eight hours happens overnight. I have left it for a bit longer when I didn't get up in time and it worked out fine.
When you are done it will look like this with the whey at the top. You have yogurt! Mix it together, save a half cup for your next starter and then put it into a different container for storage and into the fridge to cool and eat.
It will be thinner than a store bought yogurt that contains thickeners. If you want a thicker yogurt then line a strainer with coffee filters or cheese cloth and leave in the fridge until enough whey has drained off for your desired thickness.
I really enjoy the plain yogurt. It is actually less tart than the store bought kind and has a great mild taste that doesn't need flavorings. Although it tastes wonderful with berries or sometimes a dollop of homemade jam mixed in. The whey, if you strain it out, can be used in place of buttermilk in recipes so don't throw it out. We used it in pancakes and it tasted the same as if buttermilk was used.