Golden and plentiful, barley thrives in Scotland’s fields, and is arguably the most significant grain harvest. Grown twice a year, it is the Spring harvest that is preferred by the whisky industry, and given the sheer scale of demand for the golden grain you can imagine the mad dash that ensues when it comes time to harvest in August/September.

Born in 1911, Alexander Murray was a hard-working barley farmer in the rolling hills of Aberdeenshire, helping grow one of Scotland’s most famed industries. Often overlooked for its influence in producing quality whisky, today’s distillers are in constant battle for the best produce and supply.

More than its rival grains, barley is absolutely packed rich with starch, making it the perfect raw ingredient to make whisky, but there’s plenty work to be done before it becomes a dram in a glass. Barley needs to be tricked into germination then dried during the malting process; then brewed into wash (strong beer) in the milling, mashing and fermentation processes. Then onto distillation and maturation, where a very patient and temperate 3 year and 1 day minimum must be observed.

Making single malt whisky is not quite as simple as combining the three raw ingredients and flicking a switch. In fact, unlike other ingredients like grapes and other fruits, without a lot of work, the main raw ingredient – barley – contains no readily available stores of sugar to create alcohol.

In order to glean sugar from barley, it must be ‘malted’. This is a process that essentially tricks the grains to think that it’s time to germinate, which creates enzymes that help break down the starch. Once the desired level of germination is reached the process is then stopped and the malted barley is ready to be milled.

In order to trick the barley, first it is steeped with water to add moisture to the grain, after which it is spread evenly across a floor under controlled, ambient conditions. Here the grains naturally start to germinate.

Traditionally all distilleries in Scotland – at least those of centuries old – would have their own ‘maltings’, a purpose built structure designed to produce malted barley. Consisting of multiple levels to handle multiple batches, each level consists of a large floor space over which massive quantities of steeped barley would be sprawled and left to germinate. Distillery workers would carry out this task, occasionally tossing and turning the barley to allow for breathing and equal exposure to air.

Once optimal germination is achieved, the processed needs to be stopped. Traditionally a kiln is used to raise heat through the malt floor, which removes moisture from the grains, thus ceasing germination.

The result is a slightly larger grain with a toasty, sugary body, which would be conveyed across to the mill room for the next stage.

As the Scotch whisky industry grew generation-on-generation to great heights, distillery companies in the 20^th century gradually started outsourcing malting of barley to third party maltsters, who can produce malted barley on a far greater scale with far greater efficiency than the on-site traditional method.

As such, it is rare to find a working distillery maltings in Scotland, with only a handful of distilleries stubbornly holding on to their traditions. Balvenie, Laphroiag and Highland Park all continue the tradition, however only a fraction of their malted barley demands can be met by malting in house.

Modern industry adopts a process whereby a distillery will order barley from various large malting companies to deliver to the mill a certain weight of grain to a chosen specification. Multiple grain varieties are available, including optic, concerto, moonshine and many others. The barley will also have a ppm specification, i.e. how much peatiness is left in the grain in the case of peat-smoked barley.

Commercial malting embraces large industrial driers that blow hot air on to germinating grain, although the use of peat very much lives on to add smoky and earthy aroma.

The desired grist is transferred into the ‘tun room’, which houses a large vessel called a ‘mash tun’. Herein hot water is added to the crushed barley in order to extract as much sugar from the grain as possible. Every distillery employs its own routine, although it’s most common for three separate waters to be added; four less common.

Each water that is added gradually rises in temperature, ensuring that no sugar from the grist escapes capture. Scots are a canny bunch, after all. Everything is used and reused, and nothing is wasted. In fact, the final water (3 or 4 depending on distillery) will be retained and will be used as the first water in the next batch. This is called the ‘sparge’.

The result of the mash, a sugary liquid called ‘wort’ will be pumped through heat exchangers (again, nothing wasted) to the fermentation room, where it will fill a large vessel called a ‘washback’ for the next stage of the process. The spent grain is often mixed with the pot ale – the residue from the first distillation from the previous batch – to create ‘draff’, which is fed to local cattle.

Mash tuns are traditionally made from various types of wood, however given the pace of the modern whisky industry, stainless steel is now ubiquitous – far more efficient and easier to clean and maintain. Different styles of tuns are used, including lauter and semi-lauter, which mix the mash to varying degrees during the process in order to stir and agitate the grist, depending on whether the desired spirit is fruity, malty, nutty etc.

During fermentation yeast is added to the wort, which slowly bubbles and feeds on sugar, creating alcohol and carbon dioxide along the way. The carbon dioxide gas is removed from the atmosphere, while alcoholic compounds are retained. As well as alcohol, congeners are also formed: oily compounds that carry flavor.

As a general rule, a relatively short fermentation period of 2 days will promote a heavy, cereal character; on the other hand a relatively long fermentation period of 4 days will promote clean, fruity character, forming a continuum with all else in between.

The majority of Scotland’s distilleries have been making whisky the same way for generations, maintaining a consistent distillery character.

Traditionally, washbacks are made from extremely tall pieces of wood, usually larch or pine, however – as with the mash tun – some distilleries have made the switch to stainless steel vessels on the basis that it offers better efficiency. As a result there’s the age-old argument that suggests that wooden washbacks make ‘better’ whisky and that stainless alternatives are substandard. I’m sure if we added a discussion feed here it would go on a bit…

What’s certain is that because wooden vessels are harder to clean, they do retain slight build up of bacteria over time, which actually help to create certain desirable flavor compounds during longer fermentations.

Scotland’s distilleries have been utilizing copper for centuries, shaping pot stills and condensers out of this magic metal. Why is copper the go-to material?

There are a number of reasons. Firstly copper is easy to shape, which means that perfectly crafted still shapes can be sculpted. Even today all stills are hand-beaten into shape by skilled coppersmiths. Secondly copper is a fantastic conductor of heat, which is important in distillation. Thirdly, and most importantly, copper has the ability to strip out sulfur compounds that occur naturally in barley; stills made of other materials such as stainless steel make spirit that retains an unpleasant sulfury character.

As a general rule, the more copper contact to which a spirit is exposed during distillation, the lighter the body of the resulting spirit.

One disadvantage of using copper – other than the obvious fact that it’s massively expensive – is that it wears away over time. This would mean that traditionally whole stills would have to be removed and replaced during the distillery’s silent season, however it’s now more conventional for coppersmiths to remove and mend sections of stills.

Fancy buying a couple stills to get started distilling at home? Get in line. Typically the waiting list for the commission of new copper stills is a matter of years, even at Forsyth’s, the largest coppersmith company based in Rothes.

Over the centuries, engineers and distillers in Scotland’s whisky industry realized that in order to produce relatively clean spirit, i.e. maximum reduction of sulfur, vapor must be rapidly cooled at the point of condensation, hence the development of the ‘condenser’. Again, all shapes and sizes, with a school of variations involved, each condenser configuration will remove compounds from spirit in a different way. However there are two main variations that bear mentioning.

The ‘shell and tube’ condenser is the modern and fairly ubiquitous type of condenser adopted today. Its design, as its name suggests, is essentially a large cylindrical shell of copper with many thin tubes within running the height of the condenser. A cross section form the top looks not too dissimilar to a showerhead. This condenser type is very efficient at removing heavy compounds from spirit.

The ‘worm tub’ condenser is an old-fashioned type of condenser, which is still used at a handful of distilleries. A long coil of copper spirals through a bed of cold water – picturing a worm in the bathtub doesn’t help here. Worm tub condensers are less efficient at removing sulfur compounds from spirit, and distilleries that maintain the use of worms usually retain a slightly sulfury and/or meaty character.

Copper pot stills are heated at their base, which conducts heat energy towards their top. As fine a conductor of heat copper may be, inevitably every still loses heat energy meaning the observed temperature is lower. The observed difference in temperatures is known as the ‘temperature gradient’, and can be small or large depending on a still’s design or even the amount of heat used.

A large temperature gradient is one of the variables that promotes reflux in distillation.

Reflux?

During distillation reflux happens when vapours and liquids come into contact with each other. Heat is needed to turn a liquid into vapors that rise up the still. As heat is lost, some vapors condense and fall back down as liquid through the rising vapors. Whenever liquid and vapor mix in a still the heat they have is shared between them, resulting in the more volatile fractions of both becoming vapor and the less volatile fractions becoming liquid. Therefore, whenever reflux takes place it helps to increase the amount of separation between the fractions.

Distillers seeking to achieve lighter spirit need to adopt techniques that promote reflux. Temperature gradient is one, so having tall stills creates large temperature difference. However there are a handful of other influencers.

The angle, or indeed the length, of the Lynne arm – the tubular body of copper that connects to the condenser – can be key. An upwardly sloping arm will promote more reflux, as it effectively extends the height of the still, forcing vapor to climb higher before being condensed. Much of the vapor will condense prematurely and fall back into the vapor below in an upwardly sloping configuration. On the other hand, a downwardly sloping angle limits reflux, and a neutral slope centres the continuum.

Head condensers – sometimes called ‘water jackets’ or ‘bains Maries’ – can also be used. Here, cold water is circulated through an enclosed section at the top of the still at the point where vapor meets the Lynne arm. Since the water temperature is external and can be controlled, this method can be effective in controlling the desired degree of reflux. ‘Purifiers’ fall into this category.

Relatively heavy in profile as spirit, distilleries that produce these styles pay close attention to wort clarity during fermentation and distillation time, opting for cloudy wort and brisk fermentation. Maturation mellows the heavy, nutty profile, often producing light, malty whisky. The few distilleries that possess a slightly different spicy element are the result of ‘misting’: closely controlled promotion of fine grain matter entering the wash still during distillation. This profile loves to mature in sherry. Think Blair Athol, Auchroisk and Christmas cake.

Distilleries within these profiles employ processes that promote viscous or syrupy spirit. Oiliness is the result of carefully controlled reflux, whereby evaporated alcoholic vapors are encouraged, ormanipulated, to recondense within stills. Purifiers are used here. Waxiness is a relatively rare style, which is the result of interaction with fatty acid retained within the feints receiver. Think waxy/honeycomb aromas. Think Clynelish.

Forming the lighter end of the spectrum, the grassy style typically involves plenty of copper contact during distillation and maximum reflux, creating a spirit that is light in body and delicate. This profile matures relatively quickly and also takes on flavors from its cask very easily. Whilst sometimes too simple or delicate for a seasoned whisky-nut, this style represents arguably the easiest entrance to the single malt category.

Ever a canny bunch, we Scots make the most of resources – all casks maturing Scotch whisky are native to other countries, mainly USA and Spain.

Thanks to our friends making American whiskey, Scotland has a steady supply of barrels and staves every year, which are used to mature single malt and single grain whiskies all over the country. Due to being heavily charred, these barrels lend all sorts of vanilla characteristics to spirit, and their relatively small size allows for maximum surface contact, which strips unpleasant oils out of spirit.

The supply of casks from Jerez in Spain, however, is a little more complicated. Sherry is traditionally matured in a solera system, which involves new wine being added to a maturation system at the same rate from which it is drawn. So there is no real ‘ex-sherry cask’ as there is ‘ex-bourbon cask’. Instead, large casks called Butts (500L) are commissioned to be seasoned with sherry for a desired period, typically directly by the customer, i.e. a Scotch whisky producer. The ‘Sherry cask’ is the second most frequently used cask for maturation in Scotland. These add rich, Christmassy characteristics to spirit and add a syrupy quality.

Multiple casks form other origins are utilized, often to create interesting cask finishes.

Casks are used and reused until their utilization diminishes. Each time a cask is filled, its efficiency in maturing spirit actually decreases. So a first-fill Bourbon barrel and a refill Bourbon barrel maturing the same vintage of single malt will produce entirely different expressions of whisky.

First-fill casks tend to create rich whisky, influenced in by the flavor of what previously lay within. Refill casks, however, tend to better allow the distillery character of a vintage to shine through.

In every cask we sample, we are thinking ahead to its future. With a wide mix of expressions, from single casks to large vattings and batches of blended whiskies, we aim to send every cask down its own best route to achieve overall quality and depth to everything bottled under the Alexander Murray name.