Climate Change and Barley: Can Whisky's Grain Adapt?
In August 2021, Inver House suspended production at Old Pulteney because Loch Hempriggs was dangerously low. Water shortages can stop whisky production at the distillery. In the barley field, their effects begin much earlier. [8]
Barley can adapt to a changing climate. Research supports earlier sowing and breeding for resilience, while projections point to possible gains in northern Scotland alongside increasing heat and water stress elsewhere. Whether Scottish yields remain broadly viable or decline nationally depends on the projections and assumptions used. The pressures vary from field to field. [1][2][9]
Why barley's future matters to whisky
Barley is written into Scotch's legal definition. Regulation 3 of the Scotch Whisky Regulations 2009 requires Scotch to be distilled in Scotland from water and malted barley, to which only whole grains of other cereals may be added. The barley itself need not have been grown in Scotland. [10]
The Scotch Whisky Association, the industry's trade body, says malt whisky uses 100% malted barley. Grain Scotch normally uses wheat or maize alongside around 10% malted barley. This grain matters well beyond malt whisky. [2]
Scottish farms supply much of the industry's spring barley. The SWA's August 2021 technical note reports that, in 2019, 93% of spring barley processed at distilleries came from Scottish sources. That represented about 53% of Scotland's spring barley crop. The three-year average for Scottish sourcing was about 86%, showing how the share varies rather than following a permanent sourcing rule. [2]
This is one part of the wider story of sustainability in whisky. The focus here is the crop: what a changing climate does to barley, which adaptations have evidence behind them, and where the uncertainties lie.
What heat and changing rainfall do to barley
Warmth can hurry barley through its growing season without making it more productive. The James Hutton Institute's June 2022 report to the Scottish Government's Rural and Environment Science and Analytical Services division found that warming can accelerate crop development, leaving plants less time to accumulate biomass. Heat during flowering and grain filling brings further risk. [1]
Water can become scarce just when the crop needs it. In the report's modelled baseline, about 26% of Scotland's barley area was already prone to water shortage during the growing season. Its projections showed 10 to 45 mm less water in June, with higher water stress by the 2040s on prime agricultural land east of Edinburgh. [1]
Too much water creates its own problems. Adaptation Scotland reports that warmer, wetter winters in parts of south-west Scotland have been associated with lower barley yields and poorer grain quality. Rain and humidity at harvest increase the risk of pests and fungal disease that can make batches unusable. [6]
The distinction is between a harvest's weight and its usefulness. A field can produce barley without every batch being suitable for its intended use. Adaptation must protect grain quality as well as tonnes, because the harvest risks identified by Adaptation Scotland threaten both. [6]
What the projections actually say
Verdict: Disputed. Scotland's barley outlook differs between studies. The SWA's summary of research commissioned by the Scotch Whisky Research Institute in 2019 says Scottish yields are likely to remain viable on average, while barley-growing areas outside Scotland are likely to be severely compromised. That work modelled more than 27,000 soil and weather combinations, with projections extending to 2090. [2]
The Hutton report published in June 2022 gives a more adverse national outlook under the high-emissions pathway RCP8.5. It projects an overall decrease in yields by the 2040s, worsening by the 2070s, with substantial differences between regions. [1]
| Evidence | Scope | Finding |
|---|---|---|
| SWA technical note, August 2021 | Summary of commissioned modelling | Scottish yields likely to remain viable on average. [2] |
| Hutton report, June 2022 | Scottish barley under high emissions | Yields decrease overall by the 2040s, worsening by the 2070s. [1] |
| Hutton regional projections | Scottish barley growing areas | Documented projection: possible gains in the far north and north east; losses in the middle and south west. [1] |
The Hutton study used 12 climate projections, with temperature rises of 1 to 3.5°C and growing-season rainfall changes ranging from a 7% increase to a 14% decrease. For the 2040s, it projected yield increases across about 19.6% of the barley area and decreases across about 46.7%. These figures describe shares of land area, not percentage changes in the national harvest. [1]
The useful conclusion is geographical, not absolute. Location, water availability, emissions and model assumptions shape the outcome. Neither blanket reassurance nor the disappearance of Scottish barley follows from these findings: “viable on average” still leaves room for serious local difficulties. [1][2]
What the 2025 harvest tells us
Verdict: Documented. Spring and winter barley had sharply different fortunes in Scotland's 2025 harvest. The Scottish Government reported that spring crops faced the sunniest spring and hottest summer on record. The results show why the two barley crops deserve separate attention. [4]
| Crop and area | 2025 production | Change from 2024 | Reported detail |
|---|---|---|---|
| Scottish spring barley | 1,566 thousand tonnes | Down 6% | Area down 2%; yield down 4%. [4] |
| Scottish winter barley | 363 thousand tonnes | Up 11% | Record yield. [4] |
| UK spring barley | 3.9 million tonnes | Down 16% | Yield down 5.4% to 5.4 tonnes per hectare. [5] |
Across the UK, the total barley harvest was 6.4 million tonnes, down 10% from 2024. Scotland's spring barley figures also reveal two contributors to its smaller harvest: less planted area and lower yield. Describing the decline solely as a yield problem misses part of the picture. [4][5]
The harvest offers a measured example of contrasting outcomes within the same year. It is a snapshot rather than a long-term projection, valuable for what it records without setting a pattern for every future season.
How barley can adapt
Adjusting sowing dates
Earlier sowing is a viable adaptation option identified by the Hutton report. It gives growers a response to changing conditions, but brings a trade-off in frost exposure. The report also projects that the last spring frosts will occur earlier. [1]
The practical question is where and when earlier sowing makes sense. A promising modelled response does not translate into one fixed calendar date for farms across Scotland's different growing areas. Local conditions remain central to that decision.
Breeding for different pressures
Breeding can target the particular conditions barley must withstand. The SWA says it welcomes varieties better able to cope with drought or heavy rainfall. Adaptation Scotland directs distillers towards the International Barley Hub for work on climate-resilient varieties, linking the industry's grain requirements with crop research. [2][6]
Heritage barley has a practical role here. The University of the Highlands and Islands' Agronomy Institute, working with the James Hutton Institute and International Barley Hub, is breeding traits from bere into modern varieties. Those traits include tolerance of low-nutrient soils. [9]
Bere's contribution is more specific than simply keeping an old crop in cultivation. It supplies traits for investigation and incorporation into modern breeding. The evidence does not establish a comparative yield advantage for bere itself, or suggest that every older variety will outperform a modern one. [9]
Looking beyond a single yield figure
“Climate resilience” covers several distinct challenges. Drought, heavy rainfall, heat during sensitive growth stages and harvest disease put different pressures on barley. Assessing a variety means asking which of those pressures it can withstand, not just how much grain it produces. [1][2][6]
The same care applies to comparisons between crops. Winter barley's strong 2025 result records a contrasting production outcome, not a ready-made replacement strategy for the whisky industry's spring barley supply. The harvest statistics answer the question of what happened that year, rather than what the industry should plant next. [4]
What whisky producers should take from the evidence
Climate claims become clearer when three distinctions stay in view: projections versus observations, national averages versus local outcomes, and total harvest versus usable grain. A favourable result in one place or season says something useful about that setting, not necessarily the whole supply chain.
Verdict: Documented. International research adds context, with a different focus. Xie and colleagues' 2018 Nature Plants study modelled extreme drought and heat in barley-growing regions and found average barley yield losses ranging from 3% to 17%. It examined the resulting pressure on global beer supply, rather than forecasting Scotch production. [3]
The Old Pulteney shutdown also shows why climate risk cannot be confined to the farm. For whisky, barley adaptation belongs alongside water use in distilling and energy in whisky production. Each addresses a different part of production.
Earlier sowing and targeted breeding offer credible responses to the pressures on barley. Their promise is real, but the evidence does not show that they eliminate the projected risks. [1][9]
Where to go next
- Peat Bogs and the Environmental Debate: separate another land-related whisky issue from agricultural adaptation.
- Wood and Cask Sustainability: follow the sustainability question from grain to maturation.
- Lightweight Glass, Packaging and Greenwashing: examine how environmental claims are presented and assessed.
Sources
[1] James Hutton Institute, Rivington M, Jabloun M, Matthews K, Wardell-Johnson D and Miller D. Barley Responses to Climate Change: Final report to RESAS. 22 June 2022.
https://www.hutton.ac.uk/sites/default/files/files/RD2-4-1%20Barley%20Responses%20to%20Climate%20Change%20-%20Final%20report%20to%20RESAS%20-%20signed%20off.pdf
[2] Scotch Whisky Association. Scotch Whisky Cereals Technical Note. 6th edition, August 2021.
https://www.scotch-whisky.org.uk/media/1900/cereals-technical-note-6th-edition-240821.pdf
[3] Xie W and colleagues. Decreases in global beer supply due to extreme drought and heat. Nature Plants, 15 October 2018.
https://www.nature.com/articles/s41477-018-0263-1
[4] Scottish Government. Cereal and oilseed rape harvest: final estimates 2025. 2025 harvest edition.
https://www.gov.scot/publications/cereal-and-oilseed-rape-harvest-final-estimates-2025/
[5] Department for Environment, Food and Rural Affairs. Cereal and oilseed production in the United Kingdom 2025. 2025 harvest edition.
https://www.gov.uk/government/statistics/cereal-and-oilseed-rape-production/cereal-and-oilseed-production-in-the-united-kingdom-2025
[6] Adaptation Scotland. Climate change risks and adaptation in the Scotch Whisky industry. Edition supplied in the verified fact sheet, publication year not established.
https://adaptation.scot/app/uploads/2025/08/low-res-6437-as-scotch-whisky.pdf
[8] BBC News. The twin threats of flooding and drought. 5 November 2021.
https://www.bbc.co.uk/news/uk-scotland-59163739
[9] University of the Highlands and Islands, Agronomy and Agriculture Institute. Research on cereals. Undated web resource.
https://www.uhi.ac.uk/en/research-enterprise/res-themes/silk/agronomy-and-agriculture-institute/research-on-cereals/
[10] UK Government. The Scotch Whisky Regulations 2009, SI 2009/2890, regulation 3. 2009.
https://www.legislation.gov.uk/uksi/2009/2890/regulation/3
This article is desk research based on verified fact sheet TOP-A629, distinguishing research projections, official harvest estimates and attributed industry statements.
Last checked: November 2026