The spinning (sometimes called a barrel) or tumbler composter is a commercial gimmick to convince you that anyone, including small children or pets, can turn the whole pile at once in a few seconds. Most are too small to heat up properly, can’t be turned when full or nearly full, do not provide enough ventilation, do not let the compost contact the soil, and are just generally gimmicky, expensive, and useless. Turning one all day will not mix the contents as well as 15 minutes with a pitchfork or shovel on the ground. Do not waste your money, you back, or your time.
An open pile on the ground, the tackiest homemade bin, the wost designed commercial bin you could buy are all infinitely better than a tumbler or spinning compost bin. Why? They are in direct contact with the ground. Dig into a working pile and you will find insects, worms, and arachnids. The complete functional food web of the compost pile. Examine the contents of the pile in a microscope and you will find a whole additional level of the ecosystem operating (psychrophilic bacteria, mesophilic bacteria, and thermophilic bacteria), these microscopic decomposers are the real backbone of any pile. None of these things can efficiently reach your pile if it is not in direct contact with the soil.
A compost bin that suspends the pile in the air or has a bottom that blocks access to the soil is worse than useless. A bin without contact with the soil is an expensive garbage can, not a compost bin. It will be a source of smells and an attractor of unwelcome guests.
Don’t even get me started on the silly little doors at the bottom of many commercial bins designed to leave the impression that you can throw stuff in the top and shovel compost out of the bottom. There is no substitute for turning the pile. If you don’t turn the pile you have garbage, not compost.
If you want a pile that turns itself and requires minimal maintenance, an in-home worm compost bin is the real answer. These are easy to make yourself, or readily available to purchase online. Let the worms turn the pile for you! Vermicomposting worm bins can save the world because they can operate effectively in the smallest of homes.
If you want to have an outdoor pile, the old fashioned open pile, a homemade enclosure, or the simplest commercial enclosure is your best route to composting success! Effective composters are hot AND are saving the world!