CHanhyeok Kim's 'Unsleepy' furniture is fuelled by waste coffee grounds

Coffee (the beloved beverage second only to water) is a daily staple, whether sipped leisurely in conversation or guzzled by weary office workers in need of a boost. Among the many countries with high caffeine consumption, Korea ranks second in the world, also referred to as the 'Republic of Coffee', owing to the high demand. However, from the 2,00,000 tonnes of coffee beans imported each year, only 0.2 per cent of the powder reaches coffee mugs. The remaining amount—a significant one—is discarded since it contains water and, in some cases, can also release methane. Korean carpenter CHanhyeok Kim pursues possibilities in what is deemed waste here, crafting a series of furniture designs using coffee grounds: the Unsleepy Series.

"This piece is a direct expression of my design philosophy, which centres around the concept of blending. In this case, the chair is made from a mixture of discarded coffee grounds and architectural materials—an unexpected fusion that challenges traditional ideas of material use," the Korean designer tells STIR.

An experimentation in material and texture, the Unsleepy chairs and stool designs repurpose coffee waste into a composite with architectural materials called 'Coffee Dough'. The process begins by creating a mould out of paper. The dough is applied over the mould to give way to the form and texture; the result is either finished with paint or left as is. "I saw the possibility of coffee grounds in the problem. In terms of the powder, I thought it could be used like cement," Kim explains.

One of the key challenges lay in determining the ideal coffee mixture ratio—a process that took several rounds of experimentation before striking the right balance. There were also early concerns that the chair design might end up too heavy; to address this, special paper was used in place of wood, keeping the product design reasonably lightweight. As for the 'Coffee Dough', its surface is deliberately split during drying to create a richly textured finish, reminiscent of the cracks found in fermented Meju (a brick of dried, fermented soybeans, a fundamental ingredient in Korean cuisine).

"Rather than focusing on a striking or unconventional form, the emphasis is placed on the material itself. It is a proposal for both hybridisation and the potential of new materiality," the furniture designer shares. The chair's form draws subtle inspiration from hanok, a traditional Korean house and the flowing lines and columnar elements of traditional Korean architecture. Though not immediately apparent, these influences are thoughtfully merged with ergonomic design. The concept of 'leaning on a sofa while sitting on the floor' reflects a distinctly Korean approach to comfort—one that informs the intentionally lower backrest, setting it apart from a standard chair.

By transforming a daily waste product into a functional, culturally rooted design, Kim's Unsleepy Series reimagines the lifecycle of materials with craft and intention. Blending sustainability with tradition, the project invites a reconsideration of what we discard with no second thought—and what it might become when shaped by thoughtful hands and a sense of possibility.