Coffee grounds in compost
Useful in moderation, mixed with other compost ingredients.
Evidence: Practical extension guidanceProfessional review not claimed
What the sources say
Oregon State University Extension describes spent coffee grounds as a compost ingredient. They are not a dependable way to acidify soil.
Evidence assessment: Practical extension guidance. This describes the scope of the guidance we checked, not proof that the remedy works for you.
Cautions
- Keep grounds to no more than 20% of compost volume under this guidance. Excess grounds can harm plant growth.
How it is usually done
- Mix grounds with other compost materials rather than making a pile of grounds alone. Monitor moisture and turn the compost regularly.
Ingredients & category
Sources
- Oregon State University: Using coffee grounds — link and wording checked 30 September 2026
Source-checking is not clinical or veterinary review. Specific historical origin not established from the source reviewed.