Whether it’s cold brew, espresso, or laboriously preparing a pour-over, making coffee results in spent coffee grounds, which do have some use, like providing gardens with nutrients-some will even swear by its use as a skin exfoliate. But scientists in Yokohama National University (YNU) have found another use for java grounds, having used spent ground java to successfully create biodegradable plastic.

Over 6 million tons of spent coffee grounds are produced globally every year, with most of it ending up in landfills. These spent grounds contain cellulose nano-fibers, which are the basis of biodegradable plastic resins. The researchers, lead by Izuru Kawamura of YNU, extracted the cellulose nano-fibers from the spent coffee grounds, and after analyzing the results, found that the end material met their suitable uniformity requirements and integrated well with polyvinyl alcohol, the building block for plastic material used in a variety of commercial and consumer applications.

Although the teams need to do more work and research to make the biodegradable plastic made from spent coffee grounds commercially viable, researchers hope that in time, goods made from biodegradable plastic can soon replace those made from conventional plastic.

"Our ultimate goal is to establish a sustainable recycling system with our cellulose nanofibers in the coffee industry," said Kawamura in a press release. "Now, more and more restaurants and cafes have been banned from using single-use straws. Following that movement, we aim to make a transparent disposal coffee cup and straw with an additive comprising cellulose nanofibers from spent coffee grounds."