The Coffire Project

How can waste be turned into something useful and beautiful? Designer Zhekai Zhang uses the concept of sustainable design to explore a new possibility for the treatment of coffee waste. By Aarthi Mohan

The Coffire collection of lamps uses a surface finishing technique with used coffee grounds as the sustainable colouring material which mimics textures of marble completely in contrast to the mass production scenario. The eco-conscious method of staining is inspired by the ancient pit firing technique for pottery making.

Samples after low-temperature firing

The lamp is made from high-quality porcelain clay in Jingdezhen, China. After firing, the body is white, bright and glossy, and feels smooth and delicate. The glaze of the lampshade is made from coffee grounds. Currently, at least 400 billion cups of coffee are consumed worldwide each year, producing at least 8 million tons of coffee grounds. Most coffee grounds are discarded, landfilled or incinerated along with other waste. There is also a part of coffee grounds that will directly enter urban sewage discharge through the sewer. Therefore, the disposal of coffee grounds as waste will not only consume a lot of energy but also cause certain harm to the environment.

The aim of this project is to develop an ‘imperfect’ design language from the perspective of the relationship between industrial standardised production and craftsmanship. The lamps have a pink marble-like surface texture, which is a wonderful effect that no other glaze can achieve. The texture and colour produced through this firing technology are different, making each lamp unique.

It is a completely new and sustainable staining technique for a porcelain product. Compared to traditional pit firing, which tends to use toxic metals as colouring materials, the coffee grounds ensure the safety of the product. In addition, this project replaces the traditional sandpit by gas kiln to achieve mass production, solving the problem of a high waste rate of traditional pit firing. Also, the translucency of porcelain adds a form of presentation to the texture effect of the surface.

Pictures courtesy @Designer Zhekai Zhang


The innovative colouring technology used in the collection is derived from the ancient pit burning technology. During the low-temperature firing process at 700-1000°C, coffee grounds on the surface of the lamp will release biodiesel and sugar. Under the influence of temperature, humidity, coffee grounds’ concentration, and other variables, the interaction between the two substances will show a pink random texture on the surface of the lamp.

In addition, the traditional sandpits used in the pit burning process are replaced by gas kilns. Firstly, it is easier to control gas kiln as a modern firing technology in terms of operation, achieving mass production and greatly improving the yield of lamp firing. Secondly, the gas kiln can be controlled at a constant temperature, so that the colour of the fired lamp is more stable. Thirdly, since there are no trace elements in a gas kiln, the colour saturation of the fired lamp is higher.

All pictures courtesy @Designer Zhekai Zhang

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