Ceramic, Coffee ground


Made in

Biodegradable 227 Circular 213 Plant-based 165 Recyclable 115 Recycled 118 Coffee ground 9 Water 27

Ceramic, Coffee ground

Photos: Sara Baptista da Silva

Barro de Café (Coffee Clay)

The Barro de Café or Coffee Clay project arises with the principle of reusing food waste that was produced and consumed in large quantities.
Wasted Coffee was identified as the second most universally consumed beverage after water.

There is a really overwhelming amount of waste resulting from this consumption and also from its production that ends up in landfills, discarded without being considered a second use. Product Design operates to help reduce and give a more noble end to waste, the work and research have gone through several processes of gathering information to understand how the designer could help to reduce waste and how through product design, we could contribute to a healthier environment.

A clay-based material with the addition of coffee grounds was developed, guided by professionals in the field of materials engineering, chemistry and related areas of ceramics. When mixed, the material is still raw, becomes more consistent, and needs less water and fewer material resources since coffee grounds in Portugal can be collected easily and for free at coffee shops. The paste when it is fired exceeds the temperature of 400ºC. All organic matter burns and disappears, leaving only the extremely light and porous ceramic material, due to the memory that remains of the coffee grounds, the baking process was the same as the traditional method, releasing some smoke for a few seconds when the organic matter burns.

The final pieces can be easily recycled, as their chemical composition remains unchanged, and clay is an inert material for nature, containing no toxic components for the environment. Regarding the mechanical strength and despite the material containing high porosity and becoming more brittle than the usual ceramic, different ways of converting this parameter were studied. In this way, the pieces were made using technologies that create more resistant structures and the thickness of the materials is thicker, making the pieces naturally more mechanically resistant, and long-lasting than normal ceramic pieces.

The products were designed to create ways to make the environment healthier, becoming natural 'air humidifiers'. Which through the evaporation of the material, this releases water particles and humidify the environment, the 'air filters/aerators' are connected to an underwater air pump, release millions of air bubbles through the porous structure and provide oxygen and other nutrients necessary for the well-being of all marine life. The 'fresh containers' to keep food fresher for longer, avoids food waste and 'fresh pots' where the substrate is more aerated and dries the water more quickly preventing root rot and providing the necessary water for the plant.

Additional information

The development of this project comprised two phases. First, a set of laboratory tests was carried out with various ceramic materials and different amounts of organic matter, specifying a more effective paste, considering the variables weight, strength, absorption, plasticity and sustainability.
Tests of production processes, manual and industrial, such as manual modelling, were carried out using traditional techniques, hydraulic pressing and additive manufacturing. In the second phase, prototypes were designed and produced to maximise the benefits of the material, including new products and features.

Pulp preparation:
With the objective of preparing the pulp, both for laboratory characterisation and for the production of pieces, a methodology was chosen that allowed for the strictest possible reproducibility of its characteristics. The method used for the preparation of the paste was the same for all the ceramic materials explored.

Ceramic paste "blocks" are used, as sold on the market, with a consistency that allows for immediate use. These are cut into small pieces and placed in a muffle kiln for 24 hours at 50°C to dry completely. This process was necessary for both materials (clay and coffee grounds) in order to determine the dry weight. It was then possible to calculate the percentage of coffee grounds that would be used, and to mix the water.

Information submitted by the maker and edited by the Future Materials Bank.


Ceramic, coffee ground, water


School of Arts and Design Caldas Da Rainha ESAD.CR, Centre for Rapid and Sustainable Product Development – CDRSP, Laboratory CENCAL.