The Afternoon Composter

An essential requirement for sustainable lifestyles is locally composting as much waste as possible. This can be as sophisticated as a complex methane digester or as simple as burying the scraps underground. Most solutions, as is often the case, fall somewhere in between. In this post I will describe how I made the below composter in just a couple of hours last weekend.

My former system, as you can see in the following picture, was a little…uh…unrefined.

So, I found myself with a few free hours and a handful of 2x4’s and sat down to construct a crude composter. Since composting is an inexact science, it does not require an exact solution. The ideal small home composter would have a 30:1 carbon:nitrogen ratio, stay at 110°F – 160°F, and always hold the proper balance of water and oxygen. Keeping all these factors perfect would yield compost soil in about a month -- a passive, unkempt system (see above…) would take 12 to 18 months. The target for this project was a system that would produce usable compost in a reasonable amount of time (~6 months) without a great deal of maintenance or construction time required.

For the bin, I used 72 linear feet of 2x4’s, ~16 linear feet of 1x2’s, a box of 6d 2” galvanized nails, and a box of 16d 3.5” nails.

I rough-cut the 2x4’s into 3’ lengths, butted them into a 3’ x 3’ square, and fastened it using the long nails.

I used the 1x2 boards as vertical supports, fastened with the shorter nails. I didn’t have enough for full support on all sides, so I saved myself a trip to the store and made an engineering compromise: I cut as many 3’ lengths as I could (3), put one on 3 sides each, and used the remaining scrap for added support. Even with this minimal support, the final product is strong enough to support itself. If deemed necessary, I could use more scrap for added support later on.

The final phase of construction is adding more squares spaced 2 – 4” apart. The space is important to allow air flow to reach deep within the pile. Yes, some compost may spill out the slats, but not very much (and you can just toss the overflow back in the bin).

And, finally, we have the installed configuration. The bin is a little heavy to lift all at once, and I had success in moving it by tumbling it end over end (carefully!).

This bin works great as a “batch” composter: to turn the pile (once every 1 – 2 weeks), flip the bin off and next to the compost. Then, just shovel the pile back in starting from the top. This technique will allow you to keep the compost stratified with the most processed product near the middle and the newest additions at the ends. Just grab from the center of the pile for your garden.

Alternatively, you could have 2 – 3 bins in a rotation. Fill one up for 4 – 6 months, then move on to the next. You’ll end up with full bins of processed compost at regular intervals. It may be difficult for the average home to produce enough compost to make this technique possible; we have just over 1/2 cubic yard of compost at the moment.

This is just one example of an easy composter that takes very little time to build and use. Have fun using this simple design or inventing your own variations for your individual situation.