Scientists use brewery waste to grow yeast needed for beer making

Scientists from Nanyang Technological University, Singapore (NTU Singapore) have invented a new process to turn spent brewery grains into a valuable product that can grow beer yeast. 

In beer making, yeast is the key ingredient for fermentation, a process where sugars from the grains are converted into alcohol. The beer brewing process thus needs large amounts of yeast.

Spent grain amounts to as much as 85 per cent of a brewery's waste. This is of little value, so the discarded grain is often used as compost or for animal feed.

Innovative approaches to extract value and re-use these discards are actively sought by the beer industry.

Professor William Chen, Director of NTU's Food Science and Technology Programme, who is leading the research, said the new conversion process turns brewer's waste into a valuable liquid nutrient, as similar commercial liquid nutrients are sold for US$30 per litre.

In comparison, the team's upcycled liquid nutrient is produced at only a fraction of the cost. The innovation has drawn the interest of several international beverage companies, including Asia Pacific Breweries (APB) in Singapore.