Compost Thermometer
And the answer (drum roll please) is not if you're composting at home.
If you're a commercial compost maker, then perhaps you have a need for one but then again, you already know that.
Home Gardeners Need To Know...
If you're a home gardener, here's what you need to know.
If the compost pile is large enough, (roughly 4x4x4 feet) and is filled up at one time with compost-ready material, then it will start to heat up.
It will take several weeks to do this. At the two week mark after building the pile, lift it up and see if it is hot inside. If you can comfortably lay your hand on the hot material, you're fine. If your hand is too hot for comfort you're getting to the point of good composting.
Put the layers back down and walk away.
Check weekly.
As soon as the pile starts to cool down or you see some crystallization starting to form (white powder - resembling ash) then you know it is time to turn that pile as the heat has done its thing.
If you're using one of the smaller home composters that don't get a hot composting system going, then you really don't require one at all because there will be nothing to measure.
Use your hand as the compost thermometer. If your hand is comfortably warm - the pile is either beginning to compost or finishing off composting. If your hand is too hot - the pile is in full compost mode.
Do you have a question about a Compost Thermometer?