Turning waste into a tasty beverage

Tofu, also known as bean curd, is a popular food made from soybeans. One of the most common methods of producing tofu is by curdling freshly boiled soya milk, cooling it, and pressing it into a solid block. During the pressing process to remove excess water, tofu whey is generated. However, when tofu whey is discarded as an untreated waste, it creates environmental pollution as the protein and soluble sugars in the whey could contribute to oxygen depletion in the waterways. In contrast, upcycling tofu whey can be a means of generating economic returns for businesses. “The health benefits associated with soy products, coupled with changing preferences towards vegetarian diets, have fueled the growth of tofu production. As a result, the amount of tofu whey has also increased proportionally. Alcoholic fermentation can serve as an alternative method to convert tofu whey into food products that can be consumed directly. Our unique fermentation technique also serves as a zero-waste solution to the serious issue of tofu whey disposal,” explained Assoc Prof Liu.   Under the guidance of Assoc Prof Liu, Mr Chua took about three months to come up with a unique recipe to make an alcoholic beverage from tofu whey. He first made fresh soya milk from soybeans, and then used the soya milk to make tofu. In the course of making tofu, he collected the whey. Sugar, acid and yeast were added to the tofu whey, and the concoction was fermented to produce the alcoholic beverage. Mr Chua also designed a novel fermentation technique which utilises the tofu whey fully without generating any waste. The whole process of making the alcoholic beverage takes about three weeks.