Horizon Proteins: Circular Economy Innovation from Whisky By-Product to Fish Feedstock

Impact: Economic, Environmental

Description of impact

Research at Heriot-Watt University has developed, patented and demonstrated a way to extract the protein from the pot ale by-product residue of malt whisky production and transform it into feed-stocks for aquaculture. The impacts arising include:

(A) Creation of a spinout company Horizon Proteins Ltd (HP) in 2014, to exploit the new bio-technology, supporting rural circular economies and showcased by the UK government at Milan Expo 2015;

(B) Investment of circa £5 million (2018) towards exploiting research and the planning and construction start of HP’s first manufacturing plant, creating skilled jobs for the rural economy (the new plant has been designed and engineered to treat 200,000 tonnes of pot ale per annum);

(C) Conversion of whisky by-product residue to new feed-stocks for aquaculture resulted in a 600% increase in the asset value of the by-product residue;

(D) Strategic partnership with EWOS Cargill for business-to-business supply chain of HP feedstock for the salmon producer market;

(E) Environmental benefits in reduction of the chemical oxygen demand to treat the waste and using local sourcing for aquaculture feedstock, rather than using imports.

Who is affected

Aquaculture and whisky production


The impacts arising from the underpinning research are parallel increases in economic and environmental sustainability in strategic key rural industry sectors, within both the whisky and aquaculture industries. A range of impacts have resulted involving local, national and international platforms supporting business development and key policies and strategies of the circular economy. The key impacts are as follows:

(A) New Spinout Company: Horizon Proteins Ltd (HP)
Researchers decided in 2014 to commercialise the emerging process and develop the research further via a spinout company. Funding was secured through Scottish Enterprise’s elite High Growth Spinout Program (HGSP) to support the applied research transition. Horizon Protein Ltd (HP) was registered as a company in 2014 and full operations of the spin-out company commenced in 2016. HWU staff and HP subsequently identified a route to economically separate the protein and Scottish Enterprise awarded GBP575,000 assistance, along with £138,000 industrial support, to refine the process in collaboration with distillers and aquafeed manufacturers. At the announcement of the funding for HP, Eleanor Mitchell, Director of Commercialisation at Scottish Enterprise, said: "We are very excited to be supporting a project with the potential to not only create high value jobs in Scotland, but to also provide such significant value-add to the iconic Scottish food and drink industries, salmon and whisky".

By adapting techniques more commonly applied to high-value pharmaceutical products, HP developed the unique, cost-effective separation and extraction process. Ultimately, it has managed to transform a historically underused by-product and increased the sustainability of various distillery processes.

In June 2015, a key circular economy report, commissioned by Zero Waste Scotland, Scottish Government, Scottish Environment Protection Agency and enterprise agencies, which included a ‘Sector Study: Beer, Whisky and Fish’, cited Horizon Proteins (HP) 24 times in the document. HP was described as a prime example of a company creating a circular economy that ‘could offer a game-changing opportunity’ coupling both whisky and salmon industries for the important ‘meaningful contribution to rural economies’, with the ‘pot ale by-product sector valued at GBP80,000,000 being a realistic market sector value’. The report further stated that HP is a ‘key development’ and ‘a bonus as pot ale is in less competition with the cattle feed markets than draff. It may also offer a potential solution for smaller or isolated distilleries: Horizon Proteins is developing a form of their technology designed to operate at smaller scales’.

In 2015 Horizon Proteins were invited by Scottish government to showcase their pioneering circular economy approach for the food and drink by-product sectors at the Milan Expo 2015. In 2016, HP was a case study cited by Arup Associates in a Mayor of London report ‘Circular and Sharing Economy’, as a specific example of an industry converting organic waste to proteins.

(B) Joint venture with Rothes CoRDe to build HPL Manufacturing Plant.

Further key investment was raised in 2018, as a result of HP being engaged with the top two companies (Diageo and Pernod Ricard) producing more than 60% (by production volume) of Scottish whisky output. Funding of GBP4,000,000 was raised to support the construction of Horizon Proteins’ first manufacturing plant, as a joint venture with Rothes CoRDe Ltd, on their site in Rothes, Scotland. Funders included SiccaDania Venture [5.8], Danish high-net-worth individuals and the Scottish Investment Bank.
(C) New Production Plant - £4m investment supporting rural economy and jobs.

The construction process for this plant is underway (delayed due to COVID-19) and will initially be able to treat 200,000 tonnes of pot ale per annum to produce around 2,500 tonnes per annum (tpa) of sustainable protein, expanding in 2023 to full capacity of 1 million tpa of pot ale and 12,000 tonnes tpa of sustainable protein. This plant has been designed to produce revenues of GBP2.25m initially, projected to rise to GBP11.25m at full capacity.

EWOS Cargill have agreed to purchase all of the initial protein, with a specific Scottish salmon farming customer as the first key client. The construction of this plant will create around 10 skilled jobs in the Speyside rural area associated with the plant, as well as supporting in-direct supply chain roles (transport etc.).

(D) Economic Added Value

The Horizon Proteins research project was designed from inception to maximise economic impact for rural areas and researcher staff engaged key stakeholders from the whisky, aquaculture and feed industries as an advisory panel to guide direction. Researchers have engaged with the whisky industry through the Scotch Whisky Research Institute (SWRI) and the major trade body the Scotch Whisky Association (SWA), to ensure that all distillers had an input. The three major aquafeed manufacturers in Scotland, EWOS Cargill, BioMar and Skretting, were all involved in the project during its development and all three offered to carry out commercial trials of the final product. This early engagement ensured that the commercial impact pathway of the developed process was maximised.

Extraction of this protein transforms the accessible value of these liquid waste by-products. They are worth around GBP3/tonne as pot ale sold as syrup, but this increases to GBP20/tonne, when reconstructed into the Horizon Proteins dried products, resulting in an over 600% increase.

(E) Environmental Benefits

The HP process enables a reduction in the chemical oxygen demand (COD) to treat the waste and reduces the needs for imported (non-UK sourced) aquafeed. The technology is now seen as a crucial element in the development of a circular bioeconomy and specifically ‘upcycling’ in Scotland. The technology reduces environmental pollution, allows for re-use of water, lowers by-product processing costs and provides a sustainable source of protein for fish for a growing global population.
Impact statusAchieved
Impact date1 Nov 201431 Dec 2020
Category of impactEconomic, Environmental
Impact levelEuropean


  • 2021