The Beer Barrel’s Hidden Treasure: MSc Thesis Explores the Potential of Brewing Sidestreams

Most people probably know that beer is brewed using water, malt, hops and yeast – and that the process results in a golden, cold beverage. Fewer people probably give much thought to what happens to the leftover grain once the brewing process is complete, or whether it can be put to any use. But that is exactly what a Helix Lab Fellow is now setting out to investigate through her MSc thesis project.

The leftover grain is known as Brewers’ Spent Grain (BSG) and consists of ingredients such as barley, wheat or rye, which are used in the brewing process. Once the sugars have been extracted from the grain, the solid material is separated from the liquid. It can be used for purposes such as animal feed, but it also risks going to waste.

But what if the protein could be extracted from the leftover grain, allowing more of the raw material to be utilized? This is what Helix Lab Fellow Mahdis Khazraie is investigating in her MSc thesis project, where she is testing different laboratory methods to analyze and extract protein from BSG.

“The first step is to characterize three different BSG samples to investigate their content of protein, carbohydrates, starch and fat, among other things. The samples have different compositions. One consists entirely of barley, another of 50 per cent barley and 50 per cent wheat, while the third contains rye. Using different analytical methods, I will determine which sample has the highest protein content,” explains Mahdis Khazraie.

In the laboratory, she is working with enzymatic protein extraction, Soxhlet extraction to analyse fats and extractives, as well as specialized analytical methods to determine starch content. She is also examining the samples’ total nitrogen content to characterize and quantify the protein. Once the analyses have been completed, she will select the sample with the highest protein content and attempt to extract the protein in powder form.

“The project gives me the opportunity to work with laboratory processes, instruments and chemicals that I have never used before. For example, I am using Soxhlet apparatus for the first time. It is a method that I have only read about in scientific articles and seen in videos.”

This is part of what makes the project exciting for Mahdis: the opportunity to turn theoretical knowledge into practical experiments while developing her technical skills through hands-on laboratory work.

A Sustainable Brewing Mindset

Mahdis Khazraie’s project was developed in collaboration with local microbrewery SKØL, which has provided the BSG samples and is following the process from the sidelines. The brewery has long been interested in finding sustainable ways to make use of its sidestreams.

“Ever since we started, we have wanted to become increasingly sustainable. So we think it is worth investigating whether our BSG can be put to use rather than simply throwing it in the bin. And if we want to grow and scale up our brewing capacity at some point, it is interesting for us to consider this from the outset and explore what we can do with the grain that we have left over after brewing,” says Søren Holst Frøkiær, co-owner of SKØL.

That is why he and his business partner, Klaus Peter Nielsen, began actively exploring the possibility of a collaboration with Helix Lab a year ago. They attended a Matchmaking Event and subsequently got in touch with Mahdis’ supervisor at DTU, who had previously worked on extracting protein from grain and producing protein powder that could be used either in manufacturing or as animal feed.

According to Søren Holst Frøkiær, the advantage of collaborating with Helix Lab is that it gives them access to human resources, equipment and new knowledge that they would otherwise not have been able to access. At the same time, they get to learn something along the way.

“The project is the first step towards establishing whether BSG can be put to use. And we are really pleased to be part of a collaboration where we potentially get to make our production more sustainable while also contributing to an educational environment and perhaps to someone eventually getting a job at one of the larger companies. That is something we would very much like to contribute to, as much as we can,” he says.