Brewing Sustainability: How Coffee Waste is Reshaping the Future of Cafes and Construction
As the café industry keeps growing, so does the need to be smarter and more sustainable. One exciting breakthrough from RMIT University shows just how powerful a cup of coffee can be—even after it’s been brewed.
Led by Dr. Rajeev Roychand, a research team at RMIT has figured out how to take used coffee grounds and turn them into something useful: stronger, eco-friendly concrete. The process involves heating the grounds in a special way (called pyrolysis) that turns them into biochar—a carbon-rich material that can replace up to 15% of the sand usually used in concrete. The result? Concrete that’s about 30% stronger than the regular stuff.
Why does this matter?
It solves two big environmental issues at once:
It keeps tonnes of coffee waste out of landfill (which produces harmful methane gas).
It helps reduce the need for sand mining, which damages ecosystems and is becoming increasingly unsustainable.
We sat down with Dr Rajeev to ask about the inspiration behind the project. “The motivation behind our research was addressing two critical environmental challenges: the vast amounts of organic waste (including coffee grounds) ending up in landfills and generating greenhouse gases, alongside the construction industry’s growing concern over the scarcity of sand. Our innovation converts organic waste into biochar that replaces sand in concrete, transforming environmental liabilities into sustainable building solutions while advancing a carbon-reduced construction future.”
And it’s not just a good idea—it’s already happening. RMIT recently partnered with Major Road Projects Victoria and construction company BildGroup to build a real footpath in Pakenham using this new coffee-infused concrete. In that single project, they reused the grounds from about 140,000 cups of coffee—turning five tonnes of café waste into two tonnes of biochar, then mixing it into 30 cubic metres of concrete.
The success of the project has been recognised nationally. In February 2025, it won the People’s Choice award in the ‘Problem Solver’ category at Universities Australia’s Shaping Australia Awards, showing just how much the public supports smart, sustainable ideas like this.
What does this mean for café owners?
It’s a great opportunity to be part of a bigger change. By teaming up with local organisations that collect and repurpose coffee waste, cafés can help reduce landfill and support greener construction—just by doing what they already do every day.
Even better, getting involved in sustainability projects like this can improve your café’s image and attract eco-conscious customers. More people are making choices based on values, and showing that your business cares about the planet can give you a real edge.
This is part of a bigger trend in the industry: integrating sustainable practices into everyday operations. Whether it’s reducing single-use plastics, composting food scraps, or now—helping to build footpaths with coffee waste—small changes really can lead to big impact.
Dr. Rajeev believes café partnerships are key to growing this idea: “Café owners are uniquely positioned to become vital partners in this sustainability journey. They create the raw material for our innovation through their daily operations. This gives them another powerful way to demonstrate their commitment while contributing to transformative infrastructure solutions. Every cup of coffee served can now represent not just a great customer experience, but a small step toward greener cities.”
What’s next?
RMIT’s team is already looking at scaling this solution, and they’re keen to work with more cafés and councils to turn even more coffee waste into something valuable. This is your chance to be part of a circular economy—where nothing goes to waste, and everything has a second purpose. By embracing ideas like this, café owners aren’t just making great coffee—they’re helping build a more sustainable future.
Want to learn more or find out how to get involved?
‘Transforming spent coffee grounds into a valuable resource for the enhancement of concrete strength’ is published in the Journal of Cleaner Production. (DOI: 10.1016/j.jclepro.2023.138205).
rajeev.roychand@rmit.edu.au