Can we talk about the freezer trick for coffee grounds?

After 3 months of my bin getting that sour smell every time I added coffee grounds, I finally tried freezing them first in a baggie before tossing them in. It stopped the smell completely and I don't know why I waited so long to test it. Has anyone else had better luck pre-freezing certain scraps or is this just a me thing?

3 comments

3 Comments

joseph93219d agoMost Upvoted

Ha! I’m over here thinking I’m a composting genius just because I remembered to freeze my grounds. Meanwhile, you’re out here bleaching bins like a pro and making me feel like a clown. I’ll stick with my baggie trick since it’s the only thing keeping my bin from smelling like a science experiment gone wrong.

the_phoenix20d ago

Honestly, is this really that deep? A sour trash can seems like a pretty low stakes problem. I just rinse out my bin with some bleach water once a month and call it done. Freezing coffee grounds feels like an extra step for something that's not even that bad.

brown.willow20d ago

Oh man, but the bleach water thing is exactly what people try first and it doesn't fix the real issue. The freezing trick actually changes the coffee grounds chemically - when you freeze them, the cell walls break down and they release their compounds slower as they thaw in the bin. So instead of getting a sudden burst of sourness all at once, it's a slow release that the bacteria can handle without going crazy. Plus, frozen grounds actually help control moisture levels in the bin since they melt gradually rather than dumping liquid in all at once. It's like giving your compost a steady meal instead of a food coma.