Waste valorization in the alcohol beverage industry : Applications for co-product streams of beer breweries and whisky distilleries

Abstract

The production processes of whisky distilleries and beer breweries are explained and compared. The resulting waste streams are considered regarding their chemical and biological properties. A review is done on current and possible conversion pathways for these waste streams to create value added products.

Extraction methods concerning the valorization of spent hops are discussed and compared, and an overview of possible valorization pathways is provided. New challenges concerning some of these waste streams due to recent market developments are described.

Previous literature on the topic is reviewed and recent findings are presented. Case studies on the technological processes are presented for each of the co-product streams. These include spent hops, spent yeast, spent grain and pot ale. It is found that research is ongoing in all these fields and that the understanding thereof is rapidly evolving. Finally, an overview is provided of the current waste streams and their respective possible value-adding applications.