Grounds for creativity: brewing up fun and functional coffee soap customizations

"Is there any use for the coffee grounds left after making coffee?" It is possible for you to get more than just a cup of coffee, but also the possibility of turning the remaining coffee grounds into a soap. At the 9th China International College Student Innovation Competition in 2023, TENG Jiaqi, an undergraduate from the College of Computer Science and Technology of ZJU, led her team to win the gold award with the commercial design of their coffee soap.

The idea of coffee grounds soap originated from TENG's extracurricular research. As a coffee lover, she observed during her research in a café that coffee grounds were being discarded in large quantities. Although there was already a process for making soap from coffee grounds available on the market, it hadn't been commercialized and was only seen in small-scale charitable activities. This kind of pure handcrafting is very demanding in terms of operational skills, not only is it time-consuming, but also difficult to achieve satisfactory results.

Useful and fun

Combining the design-driven innovation knowledge she learned in class, TENG preliminarily designed a prototype machine for making soap from coffee grounds during a national college student competition on energy conservation and emission reduction. She managed to fix the entire process of preliminary material treatment, feeding, heating, stirring, and cooling for the coffee grounds soap in one machine. Compared to the earlier manual soap-making, her machine could produce a bar of coffee soap within 5-8 minutes, and the quality of the soap was more stable than that produced manually. She won the first prize with this solution, turning her initial idea into a truly "Useful"  technology.

TENG's next step is to introduce this technology into everyday life and achieve commercialization. Starting from this approach, the team created a "Fun" effect with customized patterns for the coffee soap. Users only need to put coffee grounds into the machine and upload a picture to select a pattern through a companion mini-program to customize their own coffee soap.

Embarking on the path of charity

While engaged in invention and creation, TENG's team also ventured down the path of charity. In a "Creative Coffee Grounds Theme Day" event they hosted in October 2023, the team members educated the public about the wonderful uses of coffee grounds: they can be used for indoor moisture absorption and deodorization, stain removal, and made into coffee soap, scented products, and more. Parents and children participated in the event together from preparing the materials to placing them into molds, and finally completing the production.

The process was filled with joy, and the children's practical skills and creativity were greatly enhanced. When the team members saw the smiles on the children's faces, they deeply felt that their efforts brought tangible value to society.

Adapted and translated from the article written by ZHENG Junyan

Translator: GU Zhaoyu ('25, Education)

Photo: the interviewees

Editor: HAN Xiao ('25 PhD, Education), TIAN Minjie