Here is the much anticipated and ridiculously easy recipe!
Ingredients:
--8 cups (half-gallon) of whole milk--pasteurized and homogenized is fine, but do NOT use ultra-pasteurized. I tried 6 cups milk made from skim milk powder and 2 cups 1% milk and it worked out fine but is thinner than store bought yogurt. The site I found this recipe on suggests adding a package of unflavored gelatin to the yogurt when you add the culture to the milk to thicken it but we're fine with thinner yogurt.
--1/2 cup store-bought natural, live/active culture plain yogurt (you need to have a starter. Once you have made your own, you can use that as a starter. Every few batches start again with store bought yogurt as the culture will weaken with time if you always use homemade yogurt for your starter.)
--frozen/fresh fruit for flavoring
--thick bath towel
Directions:
Plug in your crockpot and turn to low. Add an entire half gallon of milk. Cover and cook on low for 2 1/2 hours.
Unplug your crockpot. Leave the cover on, and let it sit for 3 hours.
When 3 hours have passed, scoop out 2 cups of the warmish milk and put it in a bowl. Whisk in 1/2 cup of store-bought live/active culture yogurt. Then dump the bowl contents back into the crockpot. Stir to combine.
Put the lid back on your crockpot. Keep it unplugged, and wrap a heavy bath towel all the way around the crock for insulation.
Go to bed, or let it sit for 8 hours. The longer you let it sit the thicker the yogurt will get but it will also get more tangy as well.
In the morning, the yogurt will have thickened---it's not as thick as store-bought yogurt, but has the consistency of low-fat plain yogurt.
Chill in a plastic container(s) in the refrigerator. Your fresh yogurt will last 7-10 days. Save 1/2 cup as a starter to make a new batch. My batch filled 3 reused 650g yogurt containers plus two small bowls for the boys breakfast.
Add fruit as desired, I added a little sugar but this may not be needed if you bled the fruit with the yogurt instead of cutting up the fruit. Honey can also be used as a sweetener instead of sugar.
Cost of making homemade yogurt:
$1.42 - skim milk powder,
$0.51 - 1% milk
$0.52 - store bought yogurt
Total cost: $2.45 plus whatever fruit you would use to flavor. Approximately $0.82 per 650g container of plain yogurt!!!
A typical fruit yogurt that I buy in the store costs $3.49 for a 650g container.