Composting 101

The basic premise of composting is simple: Biodegradable waste (food scraps, coffee grounds, old leaves) returns to the ground from whence it came. But composting can be more complex than you think. We’re here to demystify the process so you can make it a regular part of your routine.

- By Kristy Drutman

What exactly is composting, and how does it work?

Composting is the process of decomposing organic materials into rich, nurturing fertilizer. Materials are typically a mix of carbon-rich brown matter (straw, fabric, sawdust, wood chips) and nitrogen-rich green matter (grass clippings, coffee grounds, eggshells). The carbon and nitrogen found in compost is a critical food source for healthy microbes that allow for thriving soil.

There are four common methods: hot pile, cold, vermicomposting and electric cycling.

Hot pile, or aerobic, involves tossing green and brown matter into an open pile exposed to oxygen and water. This pile becomes “hot” (ideally 160°F) as bacterial microbes decompose the matter rapidly. However, overheating can cause mold or destroy healthy microbes, so you’ll need to flip the pile consistently to ensure even distribution of moisture and heat. This takes roughly six to nine months to produce fertilizer.

Cold composting, or passive composting, is a simpler but slower method. Just mix brown and green matter in your compost and let everything decompose into fertilizer over a year or two. However, while less work, this approach can lead to development of unpleasant smells, bacteria, fungi or parasites.