During Paris Design Week, the Kalve café located at Rue de Caumartin 6 has transformed into a working bio-laboratory, reimagining a commercial coffee shop as a hub for the circular economy. The exhibition showcases how daily waste streams generated by coffee production can be captured and converted into functional raw materials through four distinct workstations.
Transforming Coffee Grounds into Water Filtration Systems
Mārtiņš Mežulis has developed a water filtration system that utilizes spent coffee grounds to purify waste water accumulating in commercial espresso machine drip trays. The process requires collecting and drying grounds before converting them into biochar via a pyrolysis process. Specialists from biochar company Charcotec and Eindhoven University of Technology assisted Mežulis in treating the mass with steam at 700 degrees to manufacture the final activated carbon product.
For the Kalve exhibition, running through September 20, Mežulis constructed a working model of the filtration apparatus to demonstrate the purification sequence live to visitors. The installation highlights how consumption cycles within hospitality venues can directly yield materials necessary to sustain their own operational upkeep.
Fermenting Frothed Milk Waste into Industrial Adhesives
Katrīna Tīna Smilga redirects leftover frothed milk to produce bio-based adhesives through a controlled fermentation process. The glue relies on casein—a primary protein found in animal milk—which historically served to bind furniture, textiles, and porous building elements.
The resulting natural adhesive matches synthetic sealants in durability while remaining heat-resistant and water-repellent. Exhibition attendees can interact with the workstation by mixing ingredients themselves and testing the adhesive strength by repairing fragments of broken milk jugs.
Molding Durable Serving Trays and Display Elements
Līva Sakārne pairs the milk-based adhesive with spent coffee grounds to fabricate sturdy serving trays. Pressing and drying the blended compound creates a rigid, durable material that decomposes rapidly in nature once discarded at the end of its useful lifecycle.
To streamline production, Sakārne designed a modular press featuring interchangeable molds that generate unique surface patterns with every batch. In the café window display, Paula Punkstiņa presents “Brittle Bend,” an installation constructed by mixing wastewater from the coffee machine with gelatin and pouring the solution over silicone sheets. The resulting translucent elements catch natural light, displaying amber and rusty-gold hues.
Project Background and Future Collaboration
The exhibition marks the inaugural joint project for Found Associations. As Mārtiņš Mežulis explained, the group plans to pursue ongoing collaborations focused on developing new biomaterials, circular methodologies, and speculative design solutions for urban spaces.