Knowledge is not necessary to pleasure. Knowing how a record is manufactured does not make us better dancers. We do not need to know how to write a novel to enjoy one. Understanding how whisky is made does not magically make it taste better. If you were to give this chapter a miss, you would be none the worse for not knowing the technicalities of whisky production. Indeed, the word itself – production – is enough to put anyone off wanting to know anything about how we manage the apparent miracle of converting a cereal into the world’s most complex drink. It sounds like school and those geography lessons that weren’t about volcanoes.
However, while knowing how barley is malted – or why we extract starch from corn, or the meaning of a wash still, or wherefore the Angel’s Share – has next to no negative effect on our capacity for enjoying a dram, the story of how the contents of the glass in your hand got to be here is an extraordinary one. It sees a grain – normally malted barley, corn, rye or wheat – turned into beer, which is distilled and then aged in wood. It’s a special thing.
MALTING THE BARLEY
Any grain destined for the making of a malted whisky needs malting first. Traditionally and usually, this would be barley, which is valued for its starch-to-sugar converting enzymes. These are activated via the barley’s malting, a process that involves fooling the presently dormant grain into beginning to sprout.
While the same kind of enzymes occur naturally in other germinating grains, none are as effective as those produced by barley, which is why the mix of grains or ‘mashbill’ used for nearly all other whiskies will contain a small portion of malted barley.
STARCH TO SUGAR
Visit the average distillery and more than likely the first port of call will be the grist mill. A retro-beast of a machine, its job is to grind by hammer or roller the grain kernels and so allow for subsequent extraction of their sugars, after which the grist – the husks, flour and in-betweens – is then either mixed with hot water or actually cooked, like a soup.
Given the fact of its malting, which has already started the job of turning the starch into sugar, barley marked for the making of malt or Irish pot whiskies does not require cooking, and instead the grist is mixed or ‘mashed’ in a pot-shaped vessel known as the mash tun. The increasingly hot waters dissolve the sugars and so separate them from the barley solids, the best of which – the ‘wort’ – is drained off in preparation for fermentation.
Other grains, their starch that bit more protected, require cooking – under pressure or in enormous open tubs. As a rule of thumb, the base grain – normally wheat, corn or rye – is cooked until its starch content is suitably hydrolysed. If a single grain mash, the temperature is then lowered, the malted barley added and time allowed for the conversion of the grain’s starch to sugar. If a mixed grain style, such as is bourbon, the temperature is adjusted to accommodate the addition of the so-called flavour grain, either rye or wheat, before adding the malted barley.
In the making of bourbon and grain whiskies, the solids are not separated off from the sugary liquid, and so the ‘mash’ remains a part of the process right up until distillation.
SUGAR TO ALCOHOL
Once mashed, the resulting wort or mash is cooled and then pumped into fermentation vats or ‘washbacks’. Traditionally made of wood, but more often now of stainless steel, especially in large facilities, and reminiscent of giant covered milk pails or buckets, it is here that the sugar is converted into alcohol.
The catalyst for the change is distiller’s yeast, which when pitched has the effect of, first, using up the oxygen, a frenetic and wickedly smelly process, and then, having run out, switching to living off the sugar, with alcohol being its main by-product.
Depending on the distiller’s approach, fermentation lasts from anything between 50 and 120 hours, and is pretty much the same the world over, except that in the case of the making of most bourbon whiskies, where the water is hard, the process includes adding back a portion of the previous day’s mash. Known variously as ‘setback’ or ‘backset’, this ‘spent mash’ is high in acids, and so doubles up as both ironer out of pH scales and natural antiseptic.
Thus is beer made – less the hops. The wort or mash has now become a ‘wash’. If it’s destined to be a bourbon, then it’s 5–6% abv strength. If a malt, it’ll come in at 8–9% abv. The rest is water. Next stop: distillation.
CONCENTRATING THE BEER
Distillation is an old and simple practice: the wash is heated. The alcohol content, which evaporates at a lower temperature than water, vaporises first, and is then subsequently recaptured as it condenses back to liquid.
Do it once and the alcoholic strength of the resultant ‘low wines’ averages out at about 23% abv, at which point it is by definition a spirit, albeit a very weak one. Do it twice and the so-called ‘new make’ comes off the stills at between 68–71% abv (or at around 94.5% abv if a grain whisky). If triple distilled, as in the case of Irish pot still and a small number of single malt whiskies, it is somewhere in the eighties, depending on the distillery.
Today, and depending on grain type and individual approach, a distillery will use one or both of two types of still: pot or column. The pot still is the most traditional, and mandatory for the production of malt whisky in Scotland, while the column still, also known also as the continuous or Coffey still, was first properly introduced to the industry by Robert Stein (in 1825), improved on by Aeneas Coffey (in 1834), and widely adopted by grain whisky producers thereafter. Owing to the fact of the beer being distilled twice (sometimes three times, very occasionally more), stills generally come in pairs: the larger wash still and the low wines or spirits still.
Made of copper, the pot still is topped by a long neck and a lyne arm, which runs into a condenser. Imagine a swan, its upper torso, neck and head, something stuck on the end of its beak. Some are squat and ungainly looking, some tall and elegant.
The wash pot is filled with the new (usually all liquid) wash. Heated either by direct fire or steam, it’s brought to the boil, the vapours rising up the neck, flowing down or up the lyne arm and into the condenser, whereupon they are gradually turned back into liquid, and collected into a new wines vat. The process is then repeated through the spirits still and in a more refined way, one that sees the liquid separated or cut into three parts: foreshorts, middle and feints. The foreshorts and feints are the unwanted parts of the distillate. The middle part is what the distiller is after, and he or she will cut this according to flavour and character. The new make batch is then pumped into a spirits receiver, the whole process taking between 10 and 16 hours.
The column still goes about the business of distilling beer in a radically different way. Composed of a (normally multi-storey high) stainless steel tube and separated internally by a series of plates, the mash or beer is pumped in close to the top of the column, while steam rises up through the bottom, heating the plates. As the beer hits the plates, which get progressively hotter the further it descends, so the alcohol is vaporised and carried off into a second condensing column, where it is passed up through copper plates. These so-called rectifying plates constantly re-condense heavier gas compounds, allowing only the lightest of vapours to the top, where finally they condense into the new make. In comparison to the pot still, the column still functions continuously and distils at a much higher ratio of alcohol to water, creating a lighter style distillate.
If a combination of the column and the pot is used, the beer still is usually – in America – used to both strip and rectify the alcohol, while the pot further refines. In Canada the column is used for the production of the low wines, the pot reserved for the flavouring spirit.
FROM NEW MAKE TO NEW WHISKY
The new make taken off the stills, the batch is then usually diluted to strength (62.5–63.5% abv) and filled into oak casks.
The rudiments of the whisky cask are the same whatever the type or size. Fashioned from oak staves, they are what is known as tight (liquid holding) casks and show nothing as much as a nail or tack between them. The standard two casks used are the American Standard Barrel (bourbon) and the slightly larger hogshead (Irish and Scottish). Others include the once ubiquitous sherry butt, whisky octaves, small gallon barrels, quarter casks, barriques, port pipes, Madeira and the puncheon. The vast majority are made from American white, European, French or Japanese oak. The filled casks are transported for storage to warehouses – either on or off site. Here they reside for years, intermittently monitored by the distiller or the warehouse manager.
Once deemed ready, and unless destined to be a single cask bottling, the mature whisky is then vatted or blended with more of itself – different casks and batches of the same whisky from the same distillery, some of which may well be older than it is.
MARRY, FILTER, COLOUR, BOTTLE
After blending, there are – depending on tradition, the law and interest – a number of options before bottling.
Whatever the nature of the style, once it’s been dumped and – unless cask strength – diluted to strength, the distiller may choose to ‘marry’ the whisky, by which is meant giving the now blended batches time to settle, to get to know each other, generally in large exhausted casks, and for between three and six months. Further, in order to stop the whisky clouding, which it naturally does when at low temperatures and below 46% abv, a whisky can be chill-filtered. Finally, caramel may be used as a colour agent. (Note: both chill-filtering and colouring are a hot topic, being considered by some producers to spoil the natural taste of the whisky.)
Once ready, the whisky is bottled, capped and labelled – sometimes on site, more often off. Either that or it is sold on or swapped for the purpose of being blended with other whiskies.