What methods have you found successful in composting your coffee beans after brewing?
For all things composting, we asked lots of questions to start to identify best practices. Our friend Britt Browne, founder/owner of Finca Tierra Negra, is an awesome resource (we also provide her with lots of coffee grounds!). We followed her lead in taking the "lasagna" approach to composting, where you layer "greens" waste (food scraps, green leaves, stuff with enzymes) with "browns" (dried leaves, coffee, clippings).
In the kitchen, we store all food scraps in a decent-sized container and place it in the freezer to achieve a nice mass before adding to our outside compost. At the same time, we keep our coffee grounds stored in another container in a cupboard. When the "greens" container is full, we add it to the lasagna compost bin outside, and layer coffee, dead leaves and a "soil starter" from Finca Tierra Negra on top.
How do you find the “lasagna” compost bin method works as compared to directly adding the grounds on top of the soil?
We definitely compost it first. Coffee has a lot of nitrogen, which is great for soil, but adding it on its own to the soil can raise the pH. Also, caffeine is the coffee plant's natural, evolutionary tactic to thwart weeds and harmful pests. So left on its own on the ground, it could actually wind up harming the plants it's next to. In the compost, it will contribute to balancing out pH as all the ingredients react together.
We’ve seen different approaches to "greens" vs "browns" for composting, and have heard coffee fit into both categories by different sources. We consider all food scraps and fresh green leaves as "greens" — these basically provide a lot of enzymes to the compost pile. We usually lump brown, dead leaves, clippings, and coffee grounds together as browns, but aim to add these in a 3-to-1 ratio with greens.
What kind of coffee filters do you use? How do you responsibly dispose of the coffee filters?
We use white V60 and Chemex filters. White filters are oxygen-bleached and don't add any flavor to your coffee, whereas kraft filters contribute a kraft papery taste we can't help but notice! Coffee filters will compost best if you don't let them dry out (so keep them in your coffee or greens collection), and—as with all food scraps—they will compost quicker if you tear or break them down into smaller pieces.