- Should I sieve my compost or set it aside for curing without sieving?
- My compost is wet and can’t be sieved. What should I do?
- My compost is dripping wet. Can I dry it in the sun before sieving?
After all, who doesn’t like to hold fine-grained compost after weeks of anticipation? It’s the ultimate reward for any composter. Be it a rookie or seasoned one. The effect is therapeutic and the ritual/routine is a definite stress-buster!
However, over the years, I have come across many such queries/conversations happening in WhatsApp groups. Here’s some info that I hope clears the air.
Actually sieving is not an absolute must unless you find a lot of semi-composted clumps in your compost when you harvest. When you do, sieve the compost, take out the clumps and save them for the next batch. They will act as an accelerator or, if layered at the bottom, you can avoid using cocopeat as the bottom-most layer in your composter.
Sieving actually speeds up the curing process. We can safely assume that the biological activity in the finer compost is almost uniform and the entire lot, when stored in an aerated container, will get cured (become stable and mature) at the same time. When that happens, the compost becomes cool to touch. The best way to figure out whether it is cured or not, just mix the contents thoroughly, moisten the compost if it is dry to touch and then leave it in the aerated container for some more days. If it does not become warm again, then your compost is cured.
If you are not very keen on sieving, then just mix the contents thoroughly once you harvest the compost and store it in an aerated container. Make sure there’s sufficient moisture in it. It should not be dripping wet though. Keep checking the content once a week and dig your hands in each time to check the temperature and the moisture level. If it gets dry, then the microbial activity stops. Over a month or so, the pile will become cool to touch. But it is quite possible that you might still find some clumps here and there. Just pick out the large ones and throw them into the next batch or feed them to full-grown trees or bushes whose roots can withstand the heat generated by the clumps as they go on breaking down due to constant watering. But please do not feed them to young/tender saplings/plants for obvious reasons.
If the compost is dripping wet, then sieving becomes difficult. Just dry it in shade until it attains sievable consistency. Then go ahead with the ritual.
Most people dry the compost right after harvesting because they think the consistency should be like tealeaves. Yes, of course! But it should be moist; not dry, wrung-out tealeaves.
Some scientists like Eliot Epson define composting as “the drying process” because of the huge amount of moisture that comes out as compost tea or evaporates without us noticing it. But the final output must never be dry to touch. Microbes perish in dry conditions. You don’t want that to happen after all the hard work, do you?
More info on the science of composting can be found in the chapter ‘Earth Sympony’ in my book titled ‘Endlessly Green: Solid Waste Management for Everyone’.