Can You Compost Coffee Grounds?
Yes. Used coffee grounds are a nitrogen-rich green, roughly 20:1 C:N, and they break down quickly. Mix them in rather than dumping thick layers. Plain paper filters can go in with them.
At a glance
| Home compost pile | Yes |
|---|---|
| Green or brown | Green (nitrogen-rich) |
| Carbon to nitrogen | about 20:1 (approximate) |
| Moisture | Wet |
| Prep | None needed |
| Worm bin | Yes |
| Bokashi | Yes |
How to compost coffee grounds
Add used grounds and paper filters straight from the machine. Mix them into the pile or spread them no thicker than about 1 in (2–3 cm), then cover with browns. If you collect grounds from a café in bulk, treat them like grass clippings: a green that needs 2–3 times its volume in browns.
Many coffee shops give away bagged used grounds for free; just add extra browns to match the extra nitrogen.
What goes wrong
Thick layers of grounds pack down, lose air and grow mold. Break up clumps and mix them with leaves or shredded paper. The worry that grounds make compost too acidic is overstated; brewing removes much of the acidity and the pile evens out the rest.
Worm bins and bokashi
Worm bin: Worms do well on coffee grounds in moderation, mixed in with other food and bedding rather than as their main diet.
Bokashi: Grounds and paper filters ferment fine in bokashi.
This counts as a green. Adding a lot of it? Check the balance with the compost mix calculator.
From hopcompost.com/can-you-compost/coffee-grounds/ · General guidance, not professional advice.
Frequently asked questions
Are coffee grounds green or brown compost?
Green. They look brown, but they're nitrogen-rich at roughly 20:1 C:N, so balance them with carbon-rich browns such as leaves.
Can you put coffee filters in compost?
Yes. Plain paper filters, bleached or unbleached, break down easily and count as a brown. Coffee pods are different: plastic and aluminum pods can't be composted, and most 'compostable' pods need an industrial facility.
Can you put coffee grounds directly on the garden?
You can, in a thin layer worked into the soil or mixed with mulch. Thick layers can crust over and shed water, so composting them first is the more reliable route.