Turning coffee grounds into fuel at a circular roastery in Japan

A new coffee roasting facility, ATARAO, is a collaboration between Ergana Design and COVE COFFEE ROASTERS. Together, they’ve introduced a system that reuses 100% of collected coffee grounds as a fuel source to roast new coffee beans, turning what is typically seen as waste into a key part of a circular production process.

Every year, Japan consumes about 400,000 tonnes of coffee beans, contributing to a growing volume of coffee grounds that are usually discarded after brewing. Globally, that number reaches nearly 9 million tonnes. Although small amounts of this waste are sometimes reused as fertiliser or animal feed, the majority ends up in landfills or incinerators. The reasons include coffee grounds are heavy, bulky, and prone to mould due to their high moisture content, making collection, transport, and storage costly and inefficient.

ATARAO’s approach addresses these challenges with a multi-step system. First, the collected coffee grounds are compressed into solid blocks without the use of adhesives or additives. These blocks are then used to fuel a custom-designed roaster that burns efficiently and cleanly. The process avoids the use of gas or electricity for roasting, relying entirely on repurposed organic material sourced from nearby cafés.

The ash left behind after roasting is also put to use. Because no chemicals are added in the solidification stage, the ash can be used safely as a soil conditioner or even in ceramic glaze production.

In addition to environmental concerns, the project also encourages a shift in consumer perception. Coffee grounds, often dismissed as garbage, are reframed as a usable resource, encouraging a circular future.