The Coffire project, designed by Shanghai-based designer Zhekai Zhang, colours porcelain pendant lights with used coffee grounds, mimicking the texture of marble.

Annually, at least 400 billion cups of coffee are consumed worldwide, leaving 8 million tons of coffee grounds behind. Most of these coffee grounds end up on the landfill.

The Coffire lamps are made of high quality porcelain clay in Jingdezhen, China. After the firing process, the body is white and glossy, with a smooth feel.

The colouring technology is derived from an ancient pit burning technology. The traditional sandpits used in pit burning process are replaced by gas kilns, because these are easier to control and allow for mass production. Additionally, there are no trace elements in gas kilns, which means the colour saturation of the fired lamp is higher.

The pendant lights are covered with a liquid coffee ground mixture, wrapped in aluminium foil and fired again at a temperature of 700-1000 degrees Celsius (1300-1800 degrees Fahrenheit), where the coffee grounds release biodiesel and sugar. Traditional pit firing uses toxic metals for colouring, but the coffee grounds used in this project ensure the safety of the product.

Under the influence of temperature and humidity the interaction between the mixture and the porcelain leads to a pink random pattern on the surface of the lamp that reminds of the texture of marble. Each lamp is unique.

Photos: Zhekai Zhang