Most whisky lovers’ favourite single malts were distilled from a mash of Concerto or Optic, the barley varieties that dominated the fields of Scotland for much of the 2000s. They’ve since been supplanted by Laureate, a variety that outperforms its predecessors both on the farm and in the distillery; the first whiskies distilled from this have already hit the market, with more to follow in years to come. Despite being so vital to the whisky-making process, casual drinkers are unlikely to have heard of any of these ‘super barleys’ – even though the majority of single malt Scotch whisky is made from at least one of them.

Enter Stairway to Heaven: the imaginatively named evaluation programme run by the Malting Barley Committee (MBC) of the Maltsters’ Association of Great Britain. There is an entire consortium of breeders, farmers, maltsters, brewers and distillers working together on this cross-industry initiative, which evaluates and approves barley varieties that are suited for the malting, distilling and brewing industries in England and Scotland.

It’s a laborious process. The barley variety at the heart of a 10-year-old single malt whisky on shelves today may have started its journey more than 20 years ago, when a breeder first crossed two parent plants and created a new variety. Out of thousands of varieties created by breeders, only a handful will be fully approved by the MBC. This process usually takes anywhere from five to seven years, but once a variety is approved, it guarantees the farmer that they’re growing barley that will perform well in the maltings. Meanwhile, maltsters can rest comfortably knowing that an approved variety is going to satisfy their clients, the distillers.

“We are always looking for long-term varieties, not one-hit wonders that are going to suddenly appear and disappear”, explains Mark Ineson of Muntons, who is also chairman of the MBC. “The important thing is that it’s got to be good for maltsters, it’s got to be good for the farmer, and it’s got to be good for the distiller.”

Before the MBC even gets involved, the plant breeders have been at work for years. It takes a lot of time, commitment, dedication and resources to create a new variety. These companies invest millions annually without any guarantee of ever seeing a return on their investment. But it’s a calculated risk. They spend a lot on research and development, knowing that most of their new varieties will never be grown by farmers. However, the few varieties that successfully climb all stages of the Stairway to Heaven programme make enough on royalties to recoup the investment (and then some), and keep the entire breeding programme running.

One of the breeding companies to hit it big in recent years is Syngenta. It bred Laureate, a spring barley that became fully MBC approved in 2017. By now, it accounts for almost 70 per cent of all the barley purchased in Scotland.

“We identified it early on in the process as a standout variety”, explains Tracy Creasy, marketing manager at Syngenta. “It looked really good from a spirit yield perspective and in the field. That’s why we fast-tracked it and tried to multiply the seeds quickly, so we had enough for the Malting Barley Committee to do their trials.”

Laureate was created just like all the thousands of varieties that never even make it to the MBC. At the heart of this effort is crossbreeding, where, despite numerous improvements to the process, the mechanics remain much the same as they were in the 19th century. In essence, it is as simple as pollinating one plant with another. It’s not very ‘science-y’ at this point. There isn’t even much of a controlled environment – it’s all conventional, out-in-the-field breeding. Breeders take a variety that they know is of good quality, but could maybe be improved in certain aspects. They then crossbreed it with a variety that has other desired and complementary characteristics.

“It’s similar to how human genes work. We have genes of both our parents, yet every child has different traits from each parent,”explains Creasy. “Your mom and your dad both might have blue eyes, but you actually have green eyes. The old traits aren’t always transferable. That’s why you have to grow all those thousands of seeds out in the field and select the ones that have the characteristics you’re looking for.”

The science comes later, when plant tissue is analysed for certain markers. Maybe the most important is a glycosidic nitrile, or GN, called epiheterodendrin (EPH). New varieties are screened to identify those that are non-producers of EPH, and only such varieties enter the MBC evaluation process for distilling use, because EPH is a potential precursor of a carcinogen called ethyl carbamate (EC). EC can be detected at very low levels in some food and drink products, including soy sauce, beer, kimchi and even bread, with some countries legislating for maximum levels in certain consumable items.

When an EPH-producing variety is used in spirits production, the formation of EC is promoted by various processes during fermentation, distillation and maturation. It is also associated with extended germination periods during malting of varieties that are EPH producers. The adoption by the Scotch whisky industry of conventionally bred malting barley varieties that are EPH non-producers provides a significant contribution to product protection.

While breeders do their own testing for glycosidic nitriles, the Scotch Whisky Research Institute (SWRI) coordinates with the James Hutton Institute (JHI) to double-check that varieties are non-GN.

“There are limits of how much of this substance you can have per unit,” explains Nick Pitts, a research scientist at the SWRI. “You don’t want to be a distiller in a position where you’ve spent 20 years maturing something destined for America, and then your investment is essentially wasted because you can’t sell into that market. By using non-GN barley varieties, distillers have essentially eliminated this risk.”

Much of the analytical work on the new varieties is carried out by the Micromalting Group. Chaired by Dr David Griggs of Crisp Malt, this group is part of the MBC and decides which varieties are suitable for larger, commercial-scale tests in actual distilleries. Micromalting takes place in laboratories of commercial maltsters. They take the little half-kilo bags of barley grown on special trial sites and malt them all at a small scale, under the same laboratory conditions. “We then carry out the same distilling analysis that we would on the malt produced at our big maltings,” says Dr Griggs. “We’ll predominantly be looking at the PSY value – the predicted spirit yield.”

Pretty much everyone is after spirit yield, because that is what’s valued highly by distillers. Even a small increase in spirit yield can have huge consequences for the output of distilleries that produce millions of litres of alcohol per annum. For example, Dr Griggs remembers a recent meeting where the latest micromalting data was discussed. One of the varieties currently working its way through the approval system tested for a spirit yield of five litres of alcohol per tonne above Laureate. That may not sound like much, but it adds up when you extrapolate that to The Glenlivet, a distillery with a capacity of 21 million litres of pure alcohol per year. “You can understand there was quite a bit of enthusiasm in the meeting for that variety,” Dr Griggs adds.

Flavour is also a consideration. It might not always be a focus point, but the strength of the system is that it provides barleys that can move fairly seamlessly from one variety to the next over the years, improving their agricultural and malting quality, without impacting the flavour characteristics. According to those in the business, it’s more about the maintenance of flavour, rather than creating new flavours. Tracy Creasy points out that, while breeding for flavour is extremely hard, none of Syngenta’s varieties have ever been rejected because of flavour issues. She also adds that flavour is a difficult factor to account for, in large part because there’s really no easy way to test for flavour on a small scale.

According to research scientist Pitts, testing for flavour would take a “gargantuan effort” between all parties involved – from farmers and agricultural bodies to maltsters and lab analysts – because flavour is something that’s ultimately only discovered within the distillery. What’s more, results may not even be representative until macro trials are carried out on full-size kit.

“But at the same time, we’re gathering all this flavour data all the time”, says Pitts. “This wouldn’t happen, but if there was a situation where a new variety got released, we could detect immediately if there were flavour differences. The distillers themselves would also be the first to signal this.”

So, while impact of a variety on flavour is not of much concern, that’s not to say it isn’t considered at all. According to Dr Griggs, it is becoming of greater interest, although he believes it is more the domain of craft distillers.

“You can taste differences in new-make spirit from different varieties. We’ve got customers who were using Maris Otter, which is a famous brewing variety, and if you taste the spirit, there was a clear difference in comparison to Laureate. There might be more of an interest in flavour in the future, but I’m not sure it will become the main driver for variety selection.”

Something that is of great future importance to distillers is reducing their carbon footprint. Sustainability is one of the big buzzwords in the whisky industry, which has made a pledge to work with farmers, maltsters and the International Barley Hub to create a net-zero barley by 2045. This will not just better for the environment, but also from a commercial standpoint.

Adapting to the changing climate is part of this. In 2018, there was a massive cold wave, known as the ‘Beast from the East’, followed by a very wet spring the year after, and a dry spring in 2020. New varieties must be able to grow under all these conditions – and more. For instance, they need to be more drought resistant, or at least quite drought tolerant, while also having the ability to withstand wet roots and snow cover.

That’s why the breeders and the MBC are always on the lookout for a variety that performs better on the field, or needs fewer agricultural inputs such as pesticides and fungicides. Compared to a few decades ago, barley has also become much more efficient to malt, which means less use of energy and water. The same logic applies to malt with a higher spirit yield, as less barley is required to produce the same amount of pure alcohol.

Ultimately, using better-performing barley varieties, whether in the field or in the distillery, means higher efficiency, and thus a smaller carbon footprint. In turn, this will help distillers hit their green targets.

It remains to be seen how much more a single seed can be stretched, but MBC chairman Mark Ineson is confident the top hasn’t been reached yet: “At the moment, we may think we’re at the top of the plateau, but no doubt we’ll at some state hit another, higher plateau.”