Turning yard waste into gold. Organic Composting What is Compost? Composting is the transformation of organic material through decomposition into a soil-like material called compost. Insects, earthworms, and bacteria help in transforming the material into humus. Composting is a natural form of recycling, which continually occurs in nature. A compost pile is actually a fast-track method of changing crude organic materials into something resembling soil, called humus. Compost making is a simp.