While waiting to buy a composter, my wife and I stashed our kitchen waste in a chest freezer. Last summer, when we finally bought a compost tumbler, we emptied our frozen veggie leavings into it, added a little water and some woodpile sawdust, and turned it once or twice a day. We expected to wait a couple of months, but in three weeks we had beautiful, sweet-smelling, dark, crumbly compost! Does waste normally break down this fast, or did it have something to do with the freezing?
You’re right. Freezing prepared your kitchen waste for composting by causing cells to burst and tissues to tear as the liquids froze. It would be comparable to putting kitchen waste into a blender, which also makes it decompose faster by making more surface area available to microorganisms. But it was not only freezing your kitchen waste that gave you such pleasing results. Overall, a convergence of five favorable factors explains your success:
Food. You achieved a beautiful balance of carbon to nitrogen by using sawdust as your “brown,” which contains very little nitrogen and lots of carbon.
Moisture. In an enclosed compost tumbler, a little water often goes a long way!
Air. Your tumbler took care of aeration for you and kept the material well-mixed throughout the composting process.
Temperature. Warm summer weather helped your compost cook quickly, because warm material supports more bacteria than cold stuff does. Turning the material frequently helped keep it cooking, too.
Volume. Saving up your material gave you a hefty batch of compost capable of supporting large colonies of fungi and bacteria while retaining heat and moisture.
Freezing, grinding or blending material into “garbage soup” is an extra step that is seldom necessary, but if your goal is to speed up decomposition, it can certainly help — especially when the other factors mentioned above are present.
— Barbara Pleasant, contributing editor