Tofu, traditionally eaten in East Asia, is becoming very popular as a meat alternate because of its high protein content. However, all the tofu production produces a lot of waste, namely tofu whey. It is usually discarded after tofu production. Researchers from the National University of Singapore (NUS) decided make use of it to prevent food waste. They used it to create the first known alcoholic drink from tofu whey, which they named Sachi. Apparently it is tasty and boasts the antioxidants isoflavones.

The researchers enjoying a celebratory “coup” of Sachi. Image credits: National University of Singapore.

“The traditional way of manufacturing tofu produces a large amount of whey, which contains high levels of calcium and unique soya nutrients such as isoflavones and prebiotics. Hence, disposing tofu whey is wasteful. Very little research has been done to transform tofu whey into edible food and beverage products. I had previously worked on alcohol fermentation during my undergraduate studies in NUS, so I decided to take up the challenge of producing an alcoholic beverage using the whey. The drink turned out to be tasty, which is a pleasant surprise,” said Mr Jian-Yong Chua, PhD student from the Food Science and Technology Programme at the NUS Faculty of Science.

One common way that tofu is made is to boil soya milk and cause it to curdle in lumps, which are then squeezed into a more solid brick-shape. The liquid that it squeezed out is tofu whey. It is not so great to throw tofu whey directly into the environment because the proteins and soluble sugars can cause oxygen depletion in water systems. This new technique could turn tofu production into a zero-waste enterprise and would be more profitable for companies.

Video credits: National University of Singapore.

First, sugar and acid were added to the whey and it was pasteurized to kill any spoilage bacteria. Wine yeast was added and the beverage was left to incubate for two weeks. Mr Chua invented a new fermentation process which uses all of the whey and doesn’t create any waste. The whole process takes about three weeks.

The alcohol is fruity and sweet with 7-8% alcohol content. The formation frees the isoflavone antioxidants to make them easier for the body to absorb. The group has filed a patent for Sachi and are looking for industry partners to produce the drink on a large scale. Would you drink Sachi?