Malt whisky can be distilled from various varieties of barley, and plant breeders are continually developing new varieties to outperform the existing range. This has enabled farmers to achieve higher yields per hectare, with distillers gaining higher yields of spirit per tonne of barley.
"Developing and commercialising a new barley variety takes 8-10 years, which represents a huge financial investment for plant breeders. A potential new distilling variety is initially assessed on a small trial plot, and compared to an established variety that acts as a control. If a new variety looks robust in farm trials, it's then assessed by commercial maltsters and finally by distillers," says Eddie Douglas, commercial director at Bairds Malt, and also trade committee chairman at the Maltsters Association of Great Britain.
The results of these trials determine whether a new variety is approved by the Malting Barley Committee at the Institute of Brewing and Distilling (IBD). The approval process entails three stages. Barley varieties are initially given Provisional Approval 1, which may lead to Provisional Approval 2, or even Full Approval in the following year, if warranted by additional test results.
"Current barley varieties generally come and go within a 6-7 year window, though an example of longevity is Optic, which had a 20-year life cycle that lasted until 2013, and included 10 years as the top selling variety. Optic was particularly suited to the Scottish climate and could withstand 4-5 days of wet weather just prior to harvesting and still maintain the grain quality," adds Eddie Douglas.
Barley varieties with Full Approval for distilling use in the following year are announced each autumn by the IBD. For the 2017 harvest this is Concerto, Belgravia, Octavia and Odyssey. Of these varieties Belgravia has had the longest career, first gaining Full Approval for the 2010 harvest, which Concerto received in 2011, Odyssey in 2013 and Octavia in 2016.
Each barley variety responds differently to growing conditions and to achieve its full potential every aspect has to deliver, especially the farmer and the way the crop is managed, and of course the weather.
"The temperature and amount of sunshine sets the base line for the potential harvest, and you want enough rainfall but not too much at any one time. For example, if it is wet and cold after sowing, the seed won't germinate as well. As you approach harvest time, the drier it is the better as this makes harvesting easier. If the growing season is particularly cool and wet, as it was across Scotland in 2015, then the harvest is much later," says Peter Martin, director, Agronomy Institute, University of The Highlands and Islands, based on Orkney.
As the weather varies across Scotland, even the same barley variety can show different results depending on the local conditions where it was cultivated. Two interesting test cases are Orkney and Islay.
"Orkney is the furthest north that malting barley is grown in Scotland, and yields can be 10 per cent lower than the average on the mainland, though in some years yields can be better than the average, which is largely due to the weather. The temperatures on Orkney aren't as high as in the south of Scotland, which means cooler growing temperatures, and slightly slower growth rates, but longer day length in the summer may help to compensate for this," adds Peter Martin.
Meanwhile, Kilchoman and Bruichladdich have been distilling Islay-grown barley. "Islay is not the ideal location for growing malting barley, as there's generally more rain and less sunshine on the west coast of Scotland." says Anthony Wills, managing director, Kilchoman.
Beyond the cultivation cycle, there's another important factor.
"Everyone likes the traceability of what they're drinking, and people like the fact that we grow our own barley for the 100% Islay bottlings, which we first released in 2011.
We're also investing quite heavily to increase the amount of barley cultivated on Islay," says Anthony Wills at Kilchoman.