Horizon Proteins, based at Edinburgh’s Heriot-Watt University, specialises in the transformation of underutilised resources from the food and drink industries in to higher value, quality products.


Humans currently derive around 20% of their protein from animal-based products, however with an increasing global population, there are real questions around global food security and sustainable protein sources. If we, as a society are to maintain a healthy and varied diet, then protein fortification in food and beverage is key to meeting global nutrition challenges. However, these recovery processes need to be profitable, both economically and environmentally; so new approaches need to be considered.

Horizon Proteins, based at Edinburgh’s Heriot-Watt University, specialises in the transformation of underutilised resources from the food and drink industries in to higher value, quality products. The company has developed a patented technology for the recovery of proteins and other macromolecules present in the by-products from whisky manufacturing for use as ingredients in animal and fish feeds, which need sustainable protein sources.

The method involves recovering protein from pot ale – a liquid residue left after the malt whisky-making process. Using innovative techniques, this extracted protein is then used to replace traditional proteins used in animal feed, such as those sourced from soya bean or fish meal. By adapting techniques more commonly applied for high-value pharmaceutical products Horizon Proteins has developed a cost effective process for recovering proteins from distillation by-products. This technology adds significant value to a traditionally underused by-product, while the removal of protein from pot ale also improves performance of distillery processes, therefore also adding wider benefits when integrated with distilleries.

Initially the organisation’s focus is on the synergies between whisky and aquaculture; specifically converting the proteins in distillery by-products into a sustainable and nutritional protein feed ingredient for salmon.

Helping a new market

Over 570 million litres of alcohol are produced annually by US whiskey distilleries, yielding 121,000 tonnes of protein in the corresponding by-products. For American whiskies, there is a single by-product from distillation - wet distillers grains (WDG). WDG or distillers dried grains with solubles (DDGS) are generally used as a lower value livestock feed. Also American whiskies can be made from a range of grains (corn, rye, barley and wheat) adding to the variability of by-product composition. As this by-product is quite distinct from pot ale from Scottish malt whisky distilleries, a different strategy is required for separating out the valuable components. With support from the Industrial Biotechnology Innovation Centre (IBioIC), the project aimed to adapt Horizon Proteins’ technology to by-product streams from US grain whiskey distilleries.

IBioIC was set up to bridge the gap between education and industry and this project highlights this specialism. Horizon Proteins is an industry partner of IBioIC, while Heriot Watt University is a higher education partner. Through its Exemplar project, IBioIC’s support enabled Horizon Proteins to collaborate with experts at Heriot Watt University and accelerate research into American whiskey by-products. The project allowed the company to work closely with academics in the International Centre for Brewing and Distilling (ICBD) and Institute of Biological Chemistry, Biophysics and Bioengineering, with a research scientist employed full time at the university to develop the technical aspects of the project.

The project built on an established collaboration between Horizon Proteins and the ICBD. The Centre has an international reputation for research and excellent facilities for the production of fermented beverages, and their subsequent distillation. A key part of the project was access to by-products similar to those from American whiskey. Through the ICBD, a range of distilled spirits, conforming to different American whiskey categories (including rye whiskey, bourbon and corn whiskey) were produced and  the associated by-products were made available for the project.

Innovation overview

The project included both technical and commercial innovation. The technical side focused on characterising the by-products and developing a process for converting the by-products into valuable products. The commercial applications were investigated by matching feed sectors with their nutritional requirements and identifying the impact of grain inputs on by-product composition and feed application. 

Innovation outcomes

A detailed characterisation of by-products for model American whiskies was produced and enabled the development of strategies to separate the protein components and maximise their use as feed ingredients. The system is also scalable and transferable, therefore flexible in its use across diverse American whiskey production systems.

The project has delivered:

• Production and characterisation of by-products representative of those produced by the US whiskey industry
• Design and testing of a laboratory scale process that separates the protein component of American whiskey by-products
• Extensive proteomics identifying specific proteins of interest and impact of whiskey type on protein profile
• Dissemination via presenting at the IBioIC 3rd Annual Conference and paper submitted to the Worldwide Distilled Spirits Conference1
• Article on characterisation of American grain whiskey by-products in preparation

The technology is now at Technology Readiness Level 4, meaning validation at laboratory scale has been successful and is consistent with the requirements of potential applications. The success of the collaboration has been enabled by the support of IBioIC with Jane White, Director of R&D Horizon Proteins saying, “the support of IBioIC, both in terms of research funding and also help in accessing equipment and development space, has enabled Horizon Proteins to invest in research, progress innovation and widen technology applications to new by-product streams.”

Next steps

The work developed in this project will be presented to the whisky industry at the Worldwide Distilled Spirits Conference in May 2017. A paper on the characterisation of American grain whiskey by-products will also be published. The next step is to translate the research and learning outcomes of this project to the equivalent by-products from Scotch grain whisky. Scottish grain whisky is made from wheat or maize with similar by-products, containing both the yeast and grain fractions. The team is currently assessing integration of the protein separation technology with Scotch grain whisky processes with a holistic approach to add value across the distillery by-product chain being developed.

An additional outcome of the project was identification of specific proteins in the by-products and variability with grain input. This has led to a new research area with characterisation of these proteins and their potential to be used as functional protein ingredients being part of new Horizon Proteins research collaborations. 

1. 'The composition of co-products produced during distillation of whiskies derived from grists composed predominantly of maize and rye', CP Holmes, A Diallo, JS White, J Traub, NA Willoughby & DL Maskell. Presentation at the Worldwide Distilled Spirits Conference May 2017 and paper to be published in conference proceedings