The heat in a compost pile comes from microorganisms. In this video, you'll meet them all! Learn how to understand this invisible biological magic by reading your compost thermometer and making sure your compost microorganisms have the right balance of food, air, water, and volume. This excerpt is from a longer video series of Compost “Tea Talks" (a play on "coffee talks") - online trainings and discussions to support community-oriented on-farm food scrap composting.