The recipe I use is from this amazing site. If you haven't looked around on her site, make sure you have time because there is a lot of good stuff to see!
Anyway, here is what I am doing today. You are going to need a crock pot, 1 gallon whole milk, 2 C powdered milk, 4 oz plain Greek yogurt, whatever size jars you want/have
1 gallon of whole milk poured into the crock pot (on low)
2 C powdered milk whisk into milk (fortifies milk with extra proteins and helps thicken later)
Cook this until the temperature reaches 180 degrees (takes the most time, I leave it for about 3 hrs, then I check it periodically)
When the milk has reached 180, turn off the pot and cool the milk to between 115-95
Whisk 4 oz of plain Greek yogurt into a small amount of milk until there are no clumps
Add to the rest of the milk, pour into jars
Place in oven with the light on, UNcovered, overnight (or 8-12 hrs)
It should be smooth and look pretty solid in the morning
Cover and refrigerate.
This stuff is so versatile! We use it in place of sour cream and cream cheese. We mix our homemade jams, purees, and vanilla with it to make a yummy yogurt. OH! and honey, cannot forget honey!
There are a ton of recipes out there with Greek yogurt! Enjoy!