Filled a 200 litre dual chamber tumbler with two weeks of kitchen scraps, coffee grounds and some grass clippings. It's now a heavy sludge that sloshes when I turn it, and opening the hatch smells sharply of ammonia. There's a puddle underneath. I've been turning it every other day like the instructions said. What do I do with it now, and what did I do wrong?
Also stop turning it every other day. That advice comes from tumbler marketing and it's mostly wrong — constant turning breaks up the fungal networks and stops the pile ever holding heat. Once a week is plenty, and honestly in a tumbler once you've got the mix right you can leave it alone for two.
Same experience. My tumbler started actually working when I got lazy about it.
Keep a bag or bin of browns next to the tumbler permanently. That's the whole trick — the reason everyone ends up nitrogen-heavy is that greens arrive from the kitchen daily and browns require a trip to find. A sack of autumn leaves stashed in a corner solves composting for a year.
The puddle underneath is leachate and it's strong stuff. Don't pour it on plants neat — dilute it maybe 1:10 with water or just tip it back into the tumbler once you've added browns. On a lawn undiluted it will burn patches.
Anaerobic leachate can also contain things you don't want on food crops. I put mine back in the pile rather than on anything I'm going to eat.
Good to know, I'd been putting it straight on the raspberries and wondering why they looked unhappy.
If it's genuinely sludge and you want a shortcut, empty the whole lot into a pile on the ground on a thick bed of cardboard and leaves, mix, and let it sit. On the ground it drains, worms find it, and it forgives a lot more than a sealed drum does.
@compost_carl · 7mo ago · 3 replies
You built a nitrogen soup. Kitchen scraps, coffee and grass are all greens, all wet, all high nitrogen, and there's nothing structural in there to hold air. Ammonia smell is literally nitrogen leaving as gas because there isn't enough carbon to bind it.
Fix, today:
Target feel is a wrung-out sponge — squeeze a handful and you get a drop or two, not a trickle. Tumblers are especially prone to this because they don't drain and there are no worms or soil organisms to buffer your mistakes.
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@tomato_tobin · 7mo ago
Put in about three big boxes worth of torn cardboard over two days. Smell was gone by the second day and it actually tumbles instead of sloshing now.
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@wormbin_walt · 7mo ago
The "tear, don't shred" point matters more than people realise. Finely shredded paper mats together into a wet layer that air can't get through. Hand-torn pieces the size of a playing card keep structure.
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