Not Rotten

Actually compostable compost bags

Municipal composting programs are steadily rolling out in cities across the United States, and millions of people are now composting, some for the very first time. The most common bags used to collect food scraps at home are green bags made from PLA, or corn starch. This material takes a very long time to decompose and can be hard to distinguish from standard plastic bags. In fact, some cities won't even accept them. I suspected there must be a better solution and decided to design a kitchen scraps bag that would be welcomed by compost facilities while providing a cleaner, more convenient experience for residential customers.

Materials Research

Now, I may be comfortable getting up close and personal with my coffee grounds, but selling something like this commercially does require the bag be leakproof. This necessitates an inner barrier coating with good moisture and grease resistance. There are several companies currently developing compostable coatings made with cellulose, starch, sugarcane, and algae, but not much is publicly available. Despite this I have been lucky to find a partner interested in applications for a new bio-based coating they are developing, and am in the early stages of testing and prototyping the materials and construction.

Compostability

As the project progressed I needed to test the material for compostability in the chaos of real life. I contacted my local compost facility and they allowed me to conduct tests by burying various material samples in a fresh compost pile. This being an industrial operation, the soil temperature reached 150°F, and we let them sit for 6 weeks. At this point the materials were in different stages of decomposition. Unfortunately, we observed the PLA bags disintegrated faster, possibly due to the thinness of the material in comparison. This aspect of the product could be problematic as I'd like to to find a solution that streamlines the process for facilities.

People Research

Looking for feedback on this idea, I recruited test users in NYC where they are currently rolling out composting services, I sent volunteers a set of prototype bags for them to try out and report back on their experience. I wanted to know what works best for them - what size bags they prefer, where they store their compost, how they dispose of it, etc. The feedback has been very helpful and led to important design considerations. I continue to push this solution forward as a possible product innovation, but am eyes wide open in terms of whether or not this is the right solution.