SUSTAINABILITY
Sustainable spirit:
solving brewing and distilling's big environmental impact issues
Forging sustainable paths from barley to barrel, our alumni and University community are helping to drive brewing and distilling towards net zero.
The journey of sustainability for the brewing and distilling sector is a challenging one. From grain to glass, delivering beer and spirits to the marketplace comes with a significant environmental burden.
Professor Dawn Maskell, Director of Heriot-Watt’s International Centre for Brewing and Distilling (ICBD), explains why the pace of change to sustainable practice is urgent: “If our brewing and distilling businesses do not act sustainably in terms of the environment and people, they are not going to survive the future we face. The planet requires, and customers are demanding, sustainable production practices from start to finish. It is essential that these important industries move to cleaner, greener approaches – across the raw materials and energy sources they use through to packaging and logistics – by harnessing sustainable innovation.”
There is an economic imperative too: the brewing and distilling sectors play a vital role in the economy. The Scotch Whisky industry is estimated to have contributed £7.1 billion in gross added value to the UK economy (2022), with the value of Scotch exports topping £5.6 billion in 2023*. While estimates of brewing’s contribution to the economy vary, the brewing industry believes it is worth around £500 million in annual turnover to the Scottish economy and supports over 8,000 jobs**. The net zero future requires these industries to be environmentally healthy while remaining economic powerhouses as well.
*Source: Scotch Whisky Association. ** Source: Scotland Food and Drink
The planet requires, and customers are demanding, sustainable production practices from start to finish.”
Professor Dawn Maskell
Pioneering sustainable approaches
Across the Heriot-Watt community, through our alumni, leading researchers, and forward-thinking partners, the University is making a major contribution to the change agenda in brewing and distilling.
Tackling carbon dioxide use
Craft breweries of our size have not been able to implement carbon reducing technologies effectively and cost-efficiently before.”
Steve Stewart
Close to 500,000 tonnes of carbon dioxide (CO₂) is produced by Scottish malt and grain distilleries and breweries every year. The high costs and multiple challenges involved in carbon capture make it difficult for smaller companies to implement.
Heriot-Watt alum, Steve Stewart – who co-founded Stewart Brewing in 2004 with his wife, Jo – currently serves on the University’s ICBD’s Industry Advisory Board. He is pioneering sustainable practice: “Craft breweries of our size have not been able to implement carbon reducing technologies effectively and cost-efficiently before,” he comments, “but we’re now helping to demonstrate what’s possible. One of our founding principles was to brew great beer in a sustainable and efficient manner, so we’ve not only invested £180k in solar powered energy but also £150k in a carbon capture initiative to harvest, collect and bottle CO₂. The best part is that the electricity required to drive the CO₂ capture machines is produced by the solar panels. We’ll prevent 250 tonnes of CO₂ being released to the environment over a three-year period and will become self-sufficient by avoiding the need for liquid CO₂ made elsewhere being transported to the brewery.”
A multi-partner project involving the Ardgowan Distillery Company Ltd, leading process engineering provider Briggs of Burton, and the ICBD, is exploring carbon reducing technologies for Ardgowan’s new net-zero distillery. Heriot-Watt alum, Scott Davies, who is Head of Marketing at Briggs of Burton commented: “Both Ardgowan and Briggs of Burton are greatly benefiting from this research project. It’s providing an independent perspective and identifying opportunities across the malt whisky production process and its supply chain. As a Heriot-Watt alum, I’m delighted it has also provided a great opportunity to give back to the next generation of brewing and distilling engineers and scientists as the project is designed to overlap with MSc Brewing and Distilling projects at the University, and that has also extended the range of strategies being explored.”
Investigating ways to repurpose the 800 tonnes of biogenic CO₂ Ardgowan estimates its new distillery will produce per year, this project will provide both leadership and practical solutions for distillers, brewers, and other beverage manufacturers as they strive to address their net zero challenges. Professor Dawn Maskell, Director of ICBD, added: “Our expertise across engineering and distilling will explore and validate a wider range of strategies and provide knowledge on the various routes available to industry, regardless of scale.”
Steve Stewart, Co-founder, Stewart Brewing.
Scott Davies, Head of Marketing, Briggs of Burton.
Reusing wastewater to create green hydrogen
Materials scientist Dr Sudhagar Pitchaimuthu (left).
Globally, the distilling industry is thought to produce around 1 billion litres a year of wastewater. Scientists at Heriot-Watt have developed a way to use this wastewater to produce green hydrogen which normally consumes 20.5 billion litres of fresh water a year. Unlike natural gas, hydrogen only produces harmless water vapour when it’s burned, and so doesn’t add carbon dioxide, methane, or other greenhouse gases to the atmosphere.
Nik Willoughby, professor of sustainable bioprocessing and co-lead for manufacturing and industry at iNetz+, explains: “Our scientists are looking into how to facilitate the treatment of the industry’s global wastewater and cut green hydrogen's extensive freshwater footprint. Dr Sudhagar Pitchaimuthu, a materials scientist, and his team have developed a nanoscale material – a particle that is one 10,000th of the diameter of a human hair – to allow distillery wastewater to replace fresh water in the green hydrogen production process.
“They found that treating the wastewater with the nickel selenide nanoparticle produced similar, or slightly higher quantities, of green hydrogen from the wastewater compared to results from fresh water. This research shows how it’s possible to use the distilling industry’s waste to sustainably produce clean energy.”
This research shows how it’s possible to use the distilling industry’s waste to sustainably produce clean energy.”
Professor Nik Willoughby
Growing greener crops for sustainable spirits
Barley production depends heavily on nitrogen fertilisers which currently are made from fossil fuels. Using more sustainable fertilisers will help to make barley 'greener', but the distilling industry needs to be certain their use won’t make the crop less suitable for whisky production.
Barley experts Dr Ross Alexander and Dr Calum Holmes are leading research in ICBD, in collaboration with University College Dublin, to test barley grown with green fertilisers. “This BioCrop project is investigating how biostimulants made from algae, bacteria and yeast perform for barley growth, its health and its yield, compared with traditional fossil fuel fertilisers,” explains Dr Ross Alexander. The team hope to discover that green grown options are suitable, which would mean whisky production could rely far less on the use of non-renewable fertilisers. “Testing the barley in micro maltings in our lab gives us a very controlled way to test grains at all stages of whisky production. We’ll examine the barley on the nanoscale throughout the process to ensure it meets industry standards; that’s everything from how its seeds grow to grain size, enzyme values and soluble protein content.”
Peas are another green crop and Heriot-Watt alum, Kirsty Black, who is Master Distiller at Arbikie Distillery, has devised a way of distilling them. Peas take carbon out of the atmosphere and put it into the soil and they don’t need artificial nitrogen because they create their own. At Arbikie they under sow peas with their barley as a way to provide nitrogen to this essential whisky crop, while the peas are subsequently fermented for the distillery’s Nàdar gin and vodka, avoiding 1.54 kilograms of CO₂ being released to the atmosphere with every bottle. The Nàdar range created by Kirsty is the world’s first carbon positive spirits and part of Arbikie Distillery’s wider work to become one of the world’s most sustainable distilleries.
The Nàdar range is the world’s first carbon positive spirits.”
Kirsty Black
Kirsty Black, Master Distiller, Arbikie Distillery.
Growing grain for climate-resilience and sustainability
Dr Ross Alexander and Dr Calum Holmes are collaborating with Crisp Malt, which supplies malt to breweries and distilleries across the UK, and Syngenta, a globally recognised barley breeder, to investigate the effect of stress on barley development and its implications for the production of malt quality and spirit quality. “The particular stress we are looking at is water stress,” they explain. “Climate-change is increasing drought but also water-logging (too much water around a plant’s roots). We are investigating whether it’s possible to keep making malt of suitable quality for the distilling industry as we experience irregular temperatures, irregular rainfall and unpredictable growth conditions.”
Climate-change is increasing drought but also water-logging.”
Dr Ross Alexander
The researchers have also collaborated with Arbikie Distillery, combining Arbikie’s knowledge of agriculture with Heriot-Watt’s malting expertise, to exploit some of the known resilience present in heritage barley to reduce water and energy input into malt production. Dr Holmes commented: “Heritage barleys tend to have better abilities to thrive in harsher conditions with increased resilience to drought and disease, equalling greater adaptability to changing climate conditions. It was rewarding to see the outcomes of this research so rapidly impact raw material strategy at Arbikie Distillery, while the collaboration also contributed to our research-led teaching, benefitting our students through multiple projects that continue to explore themes around cereal sustainability.”
Discovering yeasts for co-fermentation
In response to the UN Sustainable Development Goals, the Scottish Whisky Association set responsible water use targets for the industry which are very ambitious. Shanine Smith, a PhD student within the ICBD, is helping to identify solutions to help it meet these targets. “My research, which is also supported by the Scottish Whisky Research Institute, is looking at co-fermentation for sustainability and flavour in the whisky industry,” she explains. High gravity brewing and high temperature brewing, which both use less water, are two possible solutions but these approaches can put considerable stress on the yeast used in distilling, leading to a decrease in yield and poor flavour. “There are thousands of strains of yeast, but for over 100 years whisky production has mainly used only one, Saccharomyces cerevisiae, which has been selectively bred to produce high ethanol yields (alcohol). My research aims to improve high gravity and high temperature brewing through co-fermentation, which uses more than one yeast.”
This approach potentially offers a solution to the Whisky challenges the industry faces, as co-fermentation can improve the stress tolerance of yeast. “Co-fermentation is not common in the whisky industry. The wine, and more recently the beer industries have embraced it, but research is still required to find compatible strains for the fermentation process of whisky production. Yeast can display antagonistic relationships and getting two yeast strains to work together effectively is a challenge; they have different growth profiles and will compete with one another for nutrition (the sugars), so a more dominant strain can cause the death of the other by starving it of what it needs, while some strains produce toxins which can directly kill any susceptible yeast.”
Heriot-Watt alum Barry Harrison, senior scientist at the Scottish Whisky Research Institute, is Shanine’s industrial supervisor. “I’m working with over 50 kinds of yeast to create unique pairs for co-fermentation; they equate to 1,225 possible pairings but I don’t have time to test that many. Barry is pragmatic in his focus on the end goal. He keeps my curiosity from a scientific perspective from going down too many avenues and focused on real-world applicability.” The result could be essential qualitative guidance for distillers and yeast suppliers on new yeast strains and fermentation strategies that support sustainability initiatives whilst protecting the heritage of Scotch Whisky.
