Temperature is one of the key indicators of whether or not your compost is actually composting. In spite of this, so many of us rely on our senses (sight and smell) to figure out when it’s done. Read on for a more scientific (and accurate!) way to check your compost.
Heat is one of the keys to decomposition. In compost, this heat is created by microbial activity, so when you check the temperature you can get a pretty accurate indicator of how much activity is going on, and adjust your compost as necessary by adding more water, more organic material or just giving it a good flip.
The ideal temperature range for compost is 135 to 160 F. Temperatures higher than this call kill off the beneficial organisms that get decomposition going, and temperatures lower than this range can allow breeding ground for undesirables, like flies. The best way to check your compost temperature is with a long soil thermometer. This is easy to insert through holes in the side of your compost bin. Aim for the middle of the pile and leave the thermometer in place for a bit while the temperature registers.
Correct low temperatures by adding more green material and flipping the compost. Correct high temperatures by adding more brown material and flipping. (What are “green” and “brown”?>>>>) Remember to always keep the compost pile damp to encourage activity by microbes that bring the heat!