Latvian designers transform café waste into circular design at Paris Design Week
Coffee grounds, milk, and water become materials in a closed-loop ecosystem
1Circular café concept
Four Latvian designers collaborated with Kalve Coffee to reimagine cafés as material ecosystems during Paris Design Week 2026. The project transforms daily café byproducts - coffee grounds, dirty water, and excess foamed milk - into new materials through sequential processes. Each waste stream undergoes specific treatments to create functional products, demonstrating how consumption can directly feed production. The initiative merges biodesign principles with circular economy approaches in a real café setting.
2Coffee grounds to biochar
Mārtiņš Mežulis developed a water filtration system using pyrolyzed coffee grounds transformed into biochar with CharcoTec. Eindhoven University's Yang Liu contributed steam treatment to create activated carbon for filtering coffee machine wastewater. This purified water then feeds subsequent material processes in the circular chain. The system showcases how a common café waste product can gain new functional properties through scientific treatment methods while remaining within the café ecosystem.
3Milk becomes adhesive
Katrīna Tīna Smilga's 'Milk Glue' process transforms leftover foamed milk through heating and acidification. The separated curds are dried and milled into a powder mimicking glue-like properties. This innovative material demonstrates how dairy byproducts can acquire completely new material characteristics. The process exemplifies the project's core principle of giving waste materials second lives with distinct functions within the same operational environment where they originated.
4Functional tray production
Līva Sakārne combines treated coffee grounds with milk glue and filtered water to create a moldable biomaterial. Pressed into organic-shaped wooden molds, the mixture forms takeaway trays used in Kalve Coffee's daily service. These trays replace conventional versions, directly integrating the material experiments into real café operations. The designs draw inspiration from spilled liquid patterns, visually connecting the products to their café origins while demonstrating practical circular economy applications.
5Sculptural water elements
Paula Punkstiņa transforms dirty water by combining it with glycerin and resin to create amber-colored interior elements. These sculptural pieces capture water's movement, extending the material experiments beyond functional objects into spatial design. The artworks incorporate another café byproduct into the environment, demonstrating how waste streams can contribute to aesthetic experiences while remaining within the circular system.
6Linked material chain
The project connects individual processes into a continuous chain where each output becomes the next input. This structure demonstrates how different waste streams can interact within a closed-loop system. Low-tech techniques combine with laboratory methods to show diverse approaches to material transformation. The sequence visually represents circular economy principles in action, with materials constantly changing function without leaving the café ecosystem.
7Redefining material language
Found Associations challenges traditional waste categorization by demonstrating how discarded materials can acquire new identities. The project examines both the physical transformation of substances and the linguistic shift needed to describe them. By moving beyond the 'waste' label, the designers show how byproducts can become valuable resources. This conceptual framework proves as important as the material innovations themselves for implementing circular systems.
8Operational circular model
The exhibition presents cafés as potential hubs for continuous material experimentation. Coffee grounds become filters, milk turns adhesive, and water transforms into spatial elements - all within the same operational environment. This model connects consumption directly with production, offering a scalable approach to circular economy implementation in hospitality settings. The project's real-world application in Kalve Coffee demonstrates practical viability beyond theoretical concepts.