How to Make a Plastic Soda Pop Bottle Composter for Indoor Use

Compost is a dark, earthy-like material made up of decomposing organic matter. With the help of microorganisms, this organic material turns into a soil like substance loaded with nitrogen, phosphorous, and potassium. Compost is nature's more perfect soil additive and best of all, it can be made free of charge.

Compost is usually made in a compost bin outdoors, but for apartment use or even as a classroom project, you can make a counter top compost system from a soda pop bottle.

How to make your compost column

To make this compost system, you will need a 2 litre soda pop bottle, a rubber band, a piece of nylon stocking, a scissors and a large and a small deli or cottage cheese container (see picture 2).

Place the nylon over the spout at the top of the bottle, hold in place with a rubber band (picture 3). Set the bottle upside down in the larger of the two deli containers. There should be at least half an inch of clearance to allow for drainage. In this position, use your scissors to cut two inches off the bottom of the soda pop bottle. All 2 litre plastic bottles have a small "mold ridge" in this area to guide you in cutting a straight line. Once the bottom has been cut off and removed, invert the smaller deli container and place in the bottom. It should fit snugly and act as a lid for your compost system (picture 4).

How to use your counter top compost column

Before we begin using the compost column, let's look at what can be put inside.

Due to limited counter space, most people prefer to have compost break down as quickly as possible. Vegetable and fruit scraps should be minced in the blender, and egg shells crushed with a mortar and pestle. Tea bags and coffee ground can be thrown in as is. Dead flowers should also be chopped into bits. Collect all these organic scraps in a compost bucket, until you have accumulated about a quart's worth of organic material.