Who'd have thought that I'd have such success with a thermos? I wanted to make Greek yogurt and then use what I made to start new batches*. I didn't want to spend a lot of something to keep the milk and starter at 110 degrees; I also wanted something that was not plastic. This is perfect. It holds a quart of milk, yielding 2.5 cups of yogurt each time. Of course, I can also make less if I want.