Scotland’s breweries and distilleries produce over half a million tons of spent grain each year, and a new project is turning that waste into a low-carbon flour for bakeries. The problem is straightforward: spent grain is already used as cattle feed, and while some bakers have tried grinding it into flour, the taste and indigestibility limit how much can be added. This project adapts an ancient fermentation process called *koji*—combined with modern solid-state fermentation—to transform the grains into a digestible, nutrient-rich ingredient called Koji flour. It has a light flavour and can enhance tastes like chocolate and salt, allowing bakeries to use up to 25% less of those ingredients. If successful, the impact is concrete. Koji flour has no agricultural footprint, so its carbon emissions are 60% lower than wheat flour and 90% lower than cocoa. Bakeries could cut both costs and emissions with a single swap. The team is building a pilot-scale production hub at Abertay University, working with two local bakeries and sourcing grain from breweries and distilleries around Dundee. They will test recipes with customers and run nutritional and functional tests to prepare the product for market.
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Scotland is in a unique position to contribute to circularity and the reduction of the carbon footprint of food production. The country produces over half a million tons of spent grains from its distilleries and breweries each year, most of which is used as feed for cattle. Fermtech are working with Abertay University on an innovative new use for this by-product. It is already used in limited amounts ground into flour, as a filler for certain baked goods and snacks. However, the taste and indigestibility limit how much can be used, so these efforts have stalled. The project partners have a new solution, adapting an ancient fermentation process, called 'koji', with modern Solid State Fermentation (SSF) technologies to turn these grains into useful food ingredients. The product - called 'Koji flour' - has valuable properties: it's easily digestible and contains healthy nutrients, has a light, pleasant flavour, and has the ability to enhance other flavours, such as chocolate and salt, meaning you have to use up to 25% less of those ingredients. What's most interesting about it is its carbon footprint. Because it has no agricultural footprint, it is 60% lower than wheat flour, and 90% lower than cocoa. So, a bakery can both save money and reduce their carbon emissions with one ingredient. The project is in collaboration with 2 local bakeries - Wild Hearth (Perthshire) and Saltire (Edinburgh), and the grains will come from 2 breweries and 2 distilleries in and around Dundee. The Fermtech/Abertay team will build out a pilot scale production system at a fermentation hub on-site at Abertay, and work with the bakeries to develop recipes to test with their customers. The science team will do full nutritional and functional tests to understand how to get the most out of this ingredients for bakers and consumers. Together, the team will prepare the production systems and customer applications to bring this valuable Scottish product to market.
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