Soda bottle composting lets people watch the decomposition process happen in a bottle they can hold in their hands. It’s usually done in clear soda bottles, which are cheap, easily available, relatively indestructible and transparent. Since the volume of compost produced is so small, it’s a lousy way to generate compost for the garden. However, if you want to show your children or your students what happens in a compost pile, this is a great way to do it.
Putting a micro-composter together is the work of an afternoon, but the composting process takes a couple of months. For teachers, it’s not an especially good project for the last week of school. But it’s an excellent one for the slow winter months. If the school has a garden on which compost will be applied in the spring, this project gives students a hands-on understanding of the stuff they’re spreading over the soil. In an urban setting, the micro-composter lets children see processes that might otherwise remain completely foreign to them.
Micro-composters are constructed from either two or three two-liter soda bottles cut apart so they can be filled with solid material and then fitted back together securely. Holes are punched to aerate the contents, and the bottles are filled with a mixture of damp organic materials before being closed and insulated. At this point, composting begins. (more…)