That thing about coffee grounds being "heavy" for worms finally clicked for me

I was reading a post on r/vermicompost last week and someone pointed out that coffee grounds clump up and create anaerobic pockets if you dump them in all at once. I had been doing that for like 6 months and wondering why my bin got smelly every time. Switched to sprinkling a thin layer of grounds and mixing it with shredded paper (a 1 to 3 ratio roughly) and the smell disappeared in like 3 days. The worm count seems higher too. Anyone else have a simple fix that was hiding in plain sight like this?

2 comments

2 Comments

butler.abby1mo ago

Oh man, this is so real. I had the exact same lightbulb moment but with avocado skins. I used to just toss whole avocado halves in there and wonder why my bin was just a slimy mess for weeks. Now I peel the skin off first and put the flesh in a blender with some water, then pour that in. It breaks down in like 2 days and the worms swarm it. Did you notice your bin temp changes with the coffee grounds, like it gets warmer right after you add them?

derek_ramirez1mo ago

I don't know man, I've been dumping whole handfuls of coffee grounds straight into my bin for like two years and never noticed a smell problem. Maybe my worms are just built different (or my bin is already gross enough that I don't notice). The whole anaerobic pocket thing sounds kinda like one of those worm-keeping myths that people blow out of proportion. I toss in a used filter and all without any pre-mixing, and everything seems fine.