Composting your coffee grounds not only reduces your waste volume, but coffee grounds are a beneficial addition to compost bins and piles. Coffee grounds fall under the nitrogen category of compost ingredients and you should add them with other green items such as grass clippings and kitchen scraps. While most households will not produce coffee grounds in significant amounts; be aware that coffee grounds should not comprise more than one-quarter of the entire compost volume.
Collect used coffee grounds daily as you remove them from your coffee maker. Place the coffee grounds and the filter directly into the bucket and collect them until you have enough coffee grounds and other green materials to add to your compost bin. The amount of green (wet) materials you must add to the compost bin at one time should make up a 2-inch layer on the top of your compost bin.
Add the coffee grounds and the other green materials to the top of the compost bin when you have a sufficient amount.
Place a 6 to 8-inch layer of brown (dried) materials over the green materials. Always leave your compost bin with brown materials on top to reduce odors, pests and insects.
Stir or rotate the compost materials once every one to two months.
Add enough water to the compost bin so the materials do not dry out. The compost materials should stay moist but not saturated.