Manitoba is witnessing the emergence of a flourishing beer brewing market, and malt is a core ingredient of the brewing process.
Mashing malt is one of the first steps in the beer production process, and the resulting spent grains are typically used as animal feed.
But researchers at Red River College are exploring an innovative new way to use these spent grains.
In partnership with two local brewers, Torque Brewing and Farmery, the Red River College Culinary Research Program will explore the possibility of using these two sources of spent grains to create Miso, a traditional fermented bean or grain paste that has been around for over 1,000 years. Miso is widely used to flavour soups and broths in many Asian countries like China, Japan and Korea.
From Breweries to Miso: Behind the Science
Miso develops a rich meaty flavour through a two-step fermentation process using molds and bacteria to break down the base-substrates into a rich cocktail of amino acids, free fatty acids and sugars.
The first step in the process is to create “koji” or “moldy grain” which provides a source of enzymes to the second step in the process—fermentation.
The typical starting material to make koji is polished rice, barley, or soy beans.
This research project aims to test the potential of spent grains (SG) from local brewers to act as the substrate for koji mold rather than using whole barley.
Unlike the traditional grains, spent grain is broken up and nutrients have been extracted during the wort production, so it is unknown if spent grain will provide sufficient nutrients for the koji molds to properly form or if suitable flavours develop.
As to how koji is traditionally made, the hydrated grains are inoculated with Aspergillus oryzae spores and allowed to grow for up to 48 hours to develop a thick white mat of mold, but stopped before spores develop. If spores develop, the koji has been left too long and may create flavour and safety concerns.
The koji is then mixed in with cooked and cooled soybeans or barley and up to 12% salt, then inoculated again with a miso seed culture consisting of a mixture of beneficial yeasts and bacteria.
This mixture is allowed to ferment from a minimum of 2 months up to 3 years.
This process develops the rich flavours and colours associated with miso. Unpasteurized miso also provides a source of healthy gut bacteria or probiotics.
We look forward to seeing whether spent grains from local brewers can act as the substrate for koji mold rather than using whole barley.
You can follow the progress of this miso production trial @RRCResearch.