Composters are always banging on about getting the mix right, the ratio of greens and browns and wets and dries and so on. Some composters take samples and put them under a microscope to see what life is there and adjust their mix accordingly. Like all pursuits that lend themselves to nerdery there’s a lot of scientific methodology available. But you can also just leave it alone. It might take a few years but eventually everything that was once alive will turn into plant food. Developing a composting practice is about finding your comfort zone along that spectrum.

One of the things that appeals to me about composting is that it’s a massively chaotic process that produces relatively consistent results. My inputs are fairly broad. (I aspire to One Rule Composting, the rule being “was it recently alive”, though I avoid raw meat, mainly because my heap is in a communal allotment and that rotting meat smell is a bit much. If I was in the middle of nowhere I’d be taking all the butcher’s scraps.)

But I digress, my inputs are fairly broad and thorough circumstance will often skew in a particular direction. Last year a mishap with bread collections at the bakery where I work provided me with a large amount of stale bread. This gave my heap a very yeasty vibe at first, but by the end it was black earthy mulch. Last month I was given 36 sacks of shredded laurel branches and leaves (with the most amazing almond smell thanks to the cyanide they gave off - transporting them involved keeping the windows wide open!) which now make up about a third of my nearly topped-off current heap. Thanks to a much better charity donation system at work I hardly have any bread anymore, but I bet you the end results will be the same black earthy mulch.

The process of composting always takes me by surprise too. I expect steady shrinkage as the heap settles and bigger pieces are broken down, but suddenly something will optimise and whoosh, it drops 30cm seemingly overnight. Part of me wants to do the science and optimise, but I also enjoy the ignorance of following the progress of organisms that might as well be from another planet.

The time scale exacerbates this too. I once described composting as like baking a cake really really slowly. I tend to have three heaps on the go, started three or four months apart. Any lessons learned won’t be put into practice for close to a year so progress is slow. I’ve been doing this “properly” and keeping notes since April 2021 and am about to cap off my ninth heap. In any other pursuit doing something nine times is basically nothing. I have so far to go.

That’s part of my motivation for writing this newsletter - I’ve learned plenty from others who’ve made way more than nine heaps and I think I know enough to pass on to those who’ve made way fewer.

The science of composting

This overview of compost science cropped up on the composting subreddit (which used to be really active and useful before the moderator strikes and is now… less so - nice one Reddit…) and I was surprised not to have come across it before. With the caveat that, as I said above, I am not a scientific composter, it seems like a pretty good introduction for the layperson who wants to get deeper into this stuff but finds the more technical books a bit daunting.

Biology gives a survey of the life that lives in the heap, from the different bacteria for different temperatures to the food chain of big bugs that eat medium bugs that eat tiny bugs.

Chemistry dives into the carbon:nitrogen ratio and brings some sanity. I didn’t think I’d be interested in the chemistry of the heap (no pH measures for me) but this brought some real clarity.

Physics deals with the size / air conundrum, where you need a decent size to get the heat, but gravity will squash the oxygen out, so you won’t get the heat. How do you maintain this without turning your pile all the time?

What does the river want?

James Bridle is an artist and activist whose work has crossed over with my interests a fair bit over the last decade. This talk he gave - What does the river want - might seem a bit of stretch for a composting newsletter as it’s not about composting at all, but I found it hit some of the same things I think about when I think about compost, namely that this is a collaboration with a life form that I have no way of communicating with.

Bridle’s current book (which I’ve skimmed the start of, because my capacity to actually read books all the way through just vanished in the pandemic and never came back) is called Ways of Being and it responds to the incoherent nonsense babbled by fools about so-called Artificial Intelligence (don’t get me started) by looking at the other intelligences “that have been with us all along” - animals, plants and natural systems that show complexity and knowledge.

But, as the talk makes clear, it’s not just about looking at the world and seeing patterns of intelligence we can learn from or exploit. It’s something more profound, a way of perhaps undoing the habits of extractive colonialism and capitalism of the last few hundred years, of bending the world to our whims. Planetary systems are in the process of attempting to correct humanity’s misadventures and it would be in our interests to work with them, not against them.

Anyway, well worth 35 minutes of your time.

See also Donna Harraway’s Staying with the Trouble: Making Kin in the Chthulucene, another book I love dipping into and hope to read properly one day. As Wikipedia quotes from the introduction:

Staying with the trouble means making oddkin; that is, we require each other in unexpected collaborations and combinations, in hot compost piles. We become - with each other or not at all.

Be sure and make oddkin with your compost heap this autumn.

That was the second Aerobic Digest, always a tricky one after the thrill of new beginnings. Let me know what you think and send me stuff to include! Videos, essays, resources or even your own composting stories - I’m open to all ideas at this stage.

See you in a week or so, but definitely within the month.

Pete Ashton