One of the most common methods of tofu production involves curdling boiled soy milk, cooling it, then pressing it into a block. The excess liquid that's generated takes the form of tofu whey, and it's often just discarded, potentially going on to pollute waterways. Now, however, scientists from the National University of Singapore have developed a technique for turning the whey into a tasty antioxidant-rich alcoholic beverage.

Named "Sachi," the drink was created by Associate Professor Liu Shao Quan and his PhD student Mr. Chua Jian Yong.

In a process that takes about three weeks, sugar, acid and yeast are added to tofu whey, and the mixture is then fermented. That fermentation process thoroughly utilizes all of the whey, producing no waste.

The finished product has an alcohol content of about 7 to 8 percent, is rich in antioxidants known as isoflavones (along with calcium and prebiotics), and reportedly has a slightly sweet and fruity flavor. Its shelf life is approximately four months.

"The health benefits associated with soy products, coupled with changing preferences towards vegetarian diets, have fuelled the growth of tofu production," says Liu. "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."

A patent has been filed, and the researchers are now looking for industry partners to help commercialize Sachi.