1 gallon raw milk
15 TBS. plain yogurt
Divide one gallon of milk between 5 quart jars. There should be a little room at the top to add the yogurt later.
Put the jars in a large pot (I use my canning pot because it's roomy). Fill the pot with water until it reaches the yogurt line. Use a pitcher, if available, to avoid splattering water into the jars of milk.
Turn the stove on medium-low and wait for the water to reach 105° F. Use a thermometer to be exact. It will not take long, so it needs to be baby-sat. As soon as it reaches 105° F, use a jar lifter to carefully remove the jars from the pot. Turn off the stove and leave the water. Stir 3 tablespoons of yogurt into each jar of milk and whisk to ensure it emulsifies.
Tighten lids on the jars and immediately place them in an insulated cooler. Once they are in the cooler, DO NOT move, bump, or otherwise touch it. By this time, the water in the pot on the stove should be between 105° and 110° F. If the water temperature is higher or lower than 105° to 110° F, cool or heat accordingly. Pour the water into the cooler so that it completely covers the jars. Then, shut the cooler and leave for 8 to 24 hours. I find that the longer I leave it in, the thicker the yogurt will be in the end.
When the yogurt has been in the cooler for the desired amount of time, gently take the jars out, dry them off, and set them in the refrigerator. Resist the urge to shake them. The yogurt will still be runny at this time, and that is normal. Leave them in the fridge for 24 hours. After that time you will have five quarts of yogurt!
Homemade yogurt is always a little more runny than store-bought yogurt. If it is runnier than you'd like it, strain it in a cheesecloth over a strainer. Make sure to catch and save the whey, it is valuable! It can be consumed as a probiotic drink, fed to plants and pets, or used in recipes in place of buttermilk. Straining the yogurt results in Greek yogurt.
If you get a good consistency, you can just eat the yogurt as is right out of the jar!
Tip: If you cannot get raw milk, here's how to make yogurt using pasteurized milk. Follow the same steps as above, but heat the water in the pot to 185° F. Remove the pot from heat and cool to 110° F. After it's cooled, add 2 tablespoons of yogurt to each quart of milk. Incubate the milk in the cooler at 110° F for 8 to 24 hours. Then, continue using the same steps as raw milk yogurt.
1 quart of grass-fed, pasteurized yogurt from the co-op cost $5.
1 quart of grass-fed, raw homemade yogurt cost $1.20.
Savings is $3.80 per quart, or 76%!
Printable: How to Make Raw Milk Yogurt