1 gallon of milk (we used 2%)
1 small container of yogurt with active cultures--see picture below!
Cheese cloth (you can find it in the fabric/craft section at Walmart)
Check the back of your yogurt to make sure it has active cultures. We just use vanilla yogurt since its hard to find a plain flavor in a small container, but you wont really taste any flavor.
Dump your gallon of milk into the crock-pot and let it heat up to 180 degrees (to kill the milk bacteria). On high it seems to take around 3 hours, but check it often.
Once it reaches 180 turn off the crock-pot and take off the lid to let it cool down. It needs to get to 115 degrees (to allow the yogurt bacteria to survive); this will usually take 1-2 hours.
Once it has cooled down, whisk in yogurt until well combined.
Next, place the lid back on and wrap it in a towel to keep it warm. The cool down process needs to be super slow; hence the lid, towel, and oven.
Place in the oven (turned off!!). Now let it sit and do its thing! It takes 8-12 hours, we recommend the full 12 hours.
After the 12 hours, take it out. It should be thick and look like yogurt! You can leave it just like this or go one step further to get "greek" yogurt.
To get a Greek yogurt you will need to strain it. We place Cheesecloth into a colander and then set the colander in a bowl to catch the whey strained out..see picture below :)
We usually need to use two different bowls. Cover with saran wrap, put it in the fridge, and let it sit / drain for at least three hours or even a day! The longer you let it sit the thicker your yogurt will be. When it has finished draining you will be able to see the whey in the bottom bowl:
Now scoop out the yogurt and put it into a Tupperware. We use Freezer Jam containers.
It will store in the fridge for about 3 weeks (about the life of the milk you used).
This is a "plain" Greek yogurt. We sweeten it with Homemade Jam or honey and enjoying adding nuts, granola, and fresh fruit! We even use it plain instead of sour cream.