David Burrows reports on a process being developed in Scotland to feed farmed fish with distillery leftovers
Whisky and salmon feature high on any list of food and drink associated with Scotland. And for good reason: the country has a growing international reputation for food and drink, with total sales of £14.4bn at the last count in 2014. The target for this year is £16.5bn – and the acceleration is set to continue with the announcement this month of new ambitious growth targets for the period to 2030. But is this sustainable given the additional resources required and the extra waste created?
No – and the government knows it. ‘We want Scotland to be recognised as an international leader in the sustainable use of our biological resources,” says Paul Wheelhouse, minister for business, innovation and energy. The governing SNP has identified the bioeconomy as one of four priority sectors in which it can make the biggest environmental and economic impact and in October 2016 it unveiled a £1.5m funding package to support companies working in this area.
A wee dram
The country’s whisky industry alone produces more than 4 million tonnes of bio-based waste and byproducts a year, while the fish and beer sectors produce 190,000 tonnes and 53,682 tonnes of ‘leftovers’. Better use of these will produce economic benefits of between £500m and £803m, according to Circular Economy: sector study on beer, whisky and fish, published in 2015 by consultancy Ricardo AEA.
The figures grabbed headlines and turned heads among Scottish ministers in Holyrood. ‘Our food and drink industry is already outshining the rest of the UK; imagine what making the most of the sector’s waste and byproducts will do,’ Richard Lochhead, former cabinet secretary for rural affairs, food and environment, said at the time.
Fast-forward two years and the first seeds of activity are starting to germinate. Among them is a new technology that takes low-value byproducts from Scotland’s whisky distilleries and turns them into high-value, locally produced feed for the country’s aquaculture sector. ‘We didn’t set out to start a company from this but [the process] worked much better than we ever thought,’ says Nik Willoughby, chief executive at Horizon Proteins.
The company started as a research project at Edinburgh’s Heriot-Watt University. In 2014 it was spun out into a business thanks to a £600m cheque from the high-growth programme operated by Scottish Enterprise. The funding helped to commercialise the concept. Two large-scale trials have since taken place and, by the end of this year, the first production hub should be operating at a whisky distillery in north-east Scotland owned by drinks giant Diageo.
The £3.5m hub – paid for by the investment firm West Coast Capital – will be fed by 150,000 tonnes of pot ale, a major byproduct of the whisky-making process. For every litre of alcohol about eight litres of pot ale is produced, but most is reportedly spread to land, discharged at sea or treated as wastewater. Some is used for cattle feed, but the energy demand for this is high and the returns are low – a tonne of pot ale syrup will typically fetch £30-£90. Horizon’s process is low energy and (potentially) highly lucrative.
A fishy tale
Willoughby describes the process as a form of chromatography. First the solids are removed through centrifugation, leaving an enhanced distiller’s yeast (that can be used as feed) plus a protein-rich liquid. This liquid is passed through an absorption column to which the protein ‘sticks’. ‘We then change the conditions and it unsticks,’ says Willoughby. The result is a protein solution that is concentrated and dry. ‘Water is an enemy of biological processes,’ he says, ‘so our process hugely concentrates the protein and in doing so we transport ten to 20 times less water.’
The product smells strangely fishy, but it is a vegetable protein, derived from barley. At 90%, the protein content is far higher than the benchmark for fishmeal (75%) and its lack of ‘anti-nutritional elements’ sets it apart, Willoughby claims. There are few feeds like this out there, he adds, and at the top end it is worth £1,500 a tonne – a notable mark-up on the £90 a tonne for turning pot ale into cattle feed.
A 12-week trial in Norway, using the output from one of the pilot plants at a distillery in Dufftown, Moray, suggests the protein works well for salmon growth. Horizon states: ‘There was no mortality and the growth rate was not affected, so no negative impact when replacing the standard soya protein commonly used. These preliminary trials were very positive and we are now gearing up to launch another trial to push into higher inclusion levels and with the purity of the barley protein, we are confident to be able to replace more of the fish meal protein.’
Nonethess, feed manufacturers are likely to introduce the protein gradually. Global salmon feed production relies on three major protein sources: soymeal, fishmeal and animal protein. In the UK, there is a higher proportion of ingredients from marine resources and imported vegetable protein sources such as soy, both of which come with environmental baggage. The concerns relating to overfishing are well known but replacing fish protein with soy simply removes one environmental burden and replaces it with another: rapidly rising demand for soy to feed fish and other livestock has been linked to deforestation.
‘The future of fish feed is a blend of alternatives [and] no single source will dominate as fishmeal has,’ noted Lux Research in a report published in July 2015, Tightening Fishmeal Supply Creates Opportunities for Aquaculture Feed Alternatives. Lux suggested that demand for fishmeal could exceed production well before 2020, and by 2025 there could be a 16 million tonne shortfall.
Demand for fishmeal will nearly double by then, Lux estimated, creating the need for one million tonnes of alternative high-protein meal, including plant proteins, algae and insects. The report also described how insect protein, recycled waste and algae face challenges as suitable fishmeal replacements: low production capacity, high cost and consumer aversion make them unrealistic protein sources for aquaculture feed today, Lux concluded.
The aquaculture market
Willoughby is not a lone ranger trying to disprove this. Bloomberg has reported a mergers and acquisition rush with the likes of commodity giant Cargill keen to tap into an aquaculture market that it is ‘one of the fastest-growing areas of food production’. Indeed, rising seafood consumption is making fish farming more important – the UN’s Food and Agriculture Organization says the world is now eating more farmed fish than wild catches.
Horizon should have no problem finding buyers if the price is right – it is hoping to sign contracts this year. But meeting the production capacity will require a huge effort indeed. In its 2015 report, Ricardo scored Horizon’s technology as a seven out of ten in terms of ‘readiness’ (joint highest among those assessed), with a ‘short’ timescale and ‘high’ confidence for success. Production at the first site will be up to 2,000 tonnes a year, with an overall target of 12,000 tonnes of high-protein products for the Scottish feed industry every year by 2022.
The Scottish salmon industry is the principal target. Both the volume and reliability of pot ale supply are hugely appealing to aquafeed manufacturers, says Willougby. ‘Unlike some novel proteins, whose levels of availability can fluctuate wildly, the long-lasting success of the whisky industry makes it a highly reliable source.’
Whisky is a defining pillar of the Scottish economy, so there is likely to be no shortage soon of pot ale. Indeed, Ricardo estimated that, in theory, as much as 181,000 tonnes of protein a year could be extracted from the country’s nine million tonnes of pot ale and spent wash using Horizon’s process. That is almost twice the country’s entire protein feed demand of 96,000 tonnes. Given the conservative figure of £1,500 a tonne, the potential annual value of protein in pot ale and spent wash in Scotland amounts to £272m.
Better use of waste
Better use of byproducts and wastes from the beer, whisky and fish sectors alone could generate £595m for the economy. But this requires more collaboration. ‘The ideas can look very good on paper but, once you get into the detail, you can see there are challenges,’ says Jamie Pitcairn, Scotland director at Ricardo. The key, he adds, is understanding what is available and who needs it. That’s the bit that needs to be honed.
A mapping exercise with which he has been involved – alongside Zero Waste Scotland and the Industrial Biotechnology Innovation Centre (IBioIC) – could help. Pitcairn admits it was a tricky task, partly because if products are not a waste there is no regulatory requirement to report on them.
The project identified 27 million tonnes of bioresource arisings ‘floating around’ in the Scottish economy. This has been broken down into 12 categories, including protein. It is not yet clear how the data will be used, but it could work as a dating scheme, similar to the National Industrial Symbiosis Programme (see the environmentalist, September 2015, pp 29–31). Businesses could search for resources that others have no need for; equally there could be ‘push mechanisms’ to ensure firms with potentially valuable byproducts hunt for willing outlets. ‘It has to work both ways because if you have one person that wants to find a partner and another that doesn’t it isn’t going to work,’ says Pitcairn.
Only the Scots could think of feeding their fish leftovers from whisky production, but they seem an ideal match. ‘Salmon and whisky are a natural fit,’ Willoughby says, ‘not only because they’re both produced in large quantities in Scotland, but also because the amino acid profile of barley protein is nutritionally very suitable for salmon diets.’
The concept should provide others with plenty of (sustainable) food for thought.
Horizon Proteins – a summary
Horizon Proteins began as a university research project but in November 2014 it was awarded £600,000 from Scottish Enterprise under its high-growth spin-out programme.
The team has developed a low-energy process to extract protein-rich compounds from pot ale, a byproduct from the whisky distilling industry that generally is spread to land, discharged at sea or treated as wastewater. Scotland produces about 2.34 million tonnes of pot ale each year. It is not classed as waste and has little value. Some is turned into cattle feed, but it is a high-energy process and a tonne of pot ale syrup would fetch £30–£90.
Horizon has adapted techniques usually used by high-value pharmaceutical products to recover the protein in the pot ale. The barley protein is perfect for feeding Atlantic salmon.
Farmed salmon usually eat fishmeal, but its price has quadrupled since 2000 and is far from sustainable. Soy is also used, but that has its own environmental footprint. Given more farmed fish is now eaten than wild, there is potentially big money in developing different protein sources. Horizon says its protein extract is worth £1,500 per tonne. Trials in Norway suggest the salmon react well to it and further tests could even show ‘enhanced performance’.
The concept has been tested on a large scale at a site owned by Diageo and the first commercial plant should be up and running later this year. It will take 150,000 tonnes of pot ale from three distilleries and produce up to 2,000 tonnes of extract. By 2022, the output could be as high as 12,000 tonnes.
