With the amount of yogurt I eat, I should have been making my own long ago. But it wasn’t until a couple of months back, when my grocery store stopped carrying my favorite yogurt, that I tried my hand at it for the first time and discovered how absolutely simple it is. And you don’t need a yogurt maker either–a slow cooker will do just fine! (In fact, you don’t even have to have that. Mason jars and a cooler will work, too.)
Yogurt making is so simple that it involves only two ingredients and two main steps. First, you slowly heat milk to a temperature that kills unwanted bacteria. When it has cooled back to a temperature that yogurt bacteria love, you stir in a small amount of yogurt from a previous batch and then let the mixture sit for 7 to 8 hours, all the while keeping it nice and warm so the bacteria can do their work. At the end of those 7 to 8 hours, the milk will have magically transformed into yogurt. No kidding!
One piece of special equipment you will need is a thermometer that registers temperatures between 120°F and 180°F. I use a dairy thermometer that I bought from the New England Cheesemaking Supply Company for under $6. The temperature really is the only finicky thing about yogurt making.
Also note that, while you can use pasteurized milk to make yogurt, you can’t use ultra-pasteurized milk. Unfortunately, a lot of the organic milk on the market is ultra-pasteurized. And any milk with an absurdly long shelf life has been ultra-pasteurized.
I’ve created the recipe below by combining two blog sources–Creative Simple Life and Pounds 4 Pennies–and modifying the result based on my own experience. I eat a lot of yogurt, so this recipe is for 2 quarts. In parentheses, I’ll put the quantities and cooking times for a 1-quart recipe. But remember, yogurt keeps for a couple of weeks in the fridge, so you may be able to make it in bigger batches than you think–and thus save yourself a little work.
Homemade Yogurt in the Slow Cooker
Makes 2 quarts. (1-quart directions are in parentheses.)
Time required, start to finish: 11 to 12 hours (10 to 11 hours). I usually start mine at about 6pm so it’s done at 6am the next morning.
1. Pour 2 quarts (1 qt.) of milk into your slow cooker. As noted above, do not use ultra-pasteurized milk. Also, milk with a higher fat content will make creamier yogurt. I always use whole milk. (The idea that fat makes you fat is rubbish. Fat makes you feel satisfied on fewer calories.)
2. Put lid on slow cooker and turn to HIGH. Heat until milk reaches 175°F-180°F. This will probably take about 2-1/2 hours (1-3/4 hours). You could heat the milk faster than this on the stove, but you don’t want to. It needs to be heated slowly. And you need to keep an eye on it near the end so that you don’t overheat it.
3. Turn slow cooker off and remove lid to hasten cooling. Allow to cool to 120°F. This should take about 1 hour (1/2 hour).
4. Your milk may have developed a skin. If so, use a fork to remove it and discard.
5. Stir in 2 tablespoons (1 tablespoon) plain yogurt. If you’re using store-bought yogurt as a starter, make sure you choose a yogurt with live, active cultures. (It should state this on the carton.) For future batches, simply use your own homemade yogurt in this step. Note that it is important not to mix in too much yogurt. This only crowds the bacteria.
7. Let sit undisturbed for 7 to 8 hours. The longer it sits, the tangier your yogurt will be. You could conceivably leave it for up to 12 hours. When it has reached the desired level of tang, spoon into containers and refrigerate. It should keep for about 2 weeks. (Note: Do not add sugar or other flavorings before this stage. They will interfere with the formation of the yogurt!)
Like Greek yogurt? You can make it by simply straining the recipe above. See this post on Well Preserved for details.