Yogurt warmers hold six cups. Considering the time and trouble involved in a batch of yogurt, the yield has to be a little more persuasive. After a little study of the average temperatures of yogurt warmers and food warming trays, I realized those temperatures weren’t even shouting distance from one another, so I thought about things in your house meant to safely generate some heat safely for long periods of time and stumbled on heating pads. I took an old, old roasting pan, lined it with cloth napkins and tested the temperature of water in a one quart Pyrex measuring cup and found it stayed consistently in the right range for as long as I needed. So. With careful stacking, I can get two pints and twelve 1-cup containers into the lined roaster, which is plenty of yogurt for just shy of two weeks. Also, I’m glad I had more to work with than a few paper clips.