Actually, it's steam, and what's steaming is the compost pile I wrote about yesterday. Now, I've often seen steam when I've dug into a compost heap, but I've never seen an undisturbed pile steaming away like a small volcano.
Having turned it just the day before (Are you all keeping track here? That would be on Sunday.) while adding a lot more apples and leaves, I worried that it wouldn't heat up again. Right.
The joke's on me, because not only was it steaming, but here's what the thermometer said:
There went all the plans for the morning, because at 160 the heat starts killing off some of the beneficial organisms that make compost so valuable in the soil. Out came the garden fork, rake, and wheelbarrow, and I once again set about turning the whole pile. I suppose I could have just uncovered that overheated core, but I have my reputation to consider: does that low-key and sensible solution sound manic? No.
This time I added a huge garbage can full of shredded bark (okay, I added the bark, not the can) saved for me by yet another neighbor since last summer. The bark is dry and as brown as brown; surely this high-carbon, no liquid addition would slow things down? I also removed maybe a wheelbarrow's worth of hot innards to help start up yet another pile. I know this may seem excessive, but the idea of having enough compost–and not having to buy any!–is a serious motivator.
Given the falling temperatures and the chance of snow, both piles received a generous layer of (scavenged) leaves for insulation. To keep the leaves from blowing away, I laid long sticks and, even better, lengths of vine scavenged from a disposal pile down the alley, over the heaps. The tender, young pile I then covered with a tarp, to improve insulation and the chance that it will heat up. Tarps aren't generally recommended over compost, which needs oxygen, but the sticks will, I hope, hold the tarp away from the loosely heaped–up leaves, so there should be a good buffer of air around the core. We'll see.
The tarp, like the sticks, the leaves beneath them, and the corn gluten meal for nitrogen, is an experiment. Indeed, I think of these piles as a series of composting experiments, one object of which is to find out at what temperature it actually does get too cold to start up a pile. Today it's been either a few degrees above, or a few degrees below freezing, depending on what thermometer or website you consult. When I finally came inside, it had started to snow.