How Whisky Is Made, Part 2: The Magic of Distillation
In Part 1, we left our story with "wash" — a humble, beer-like liquid of 7-10% alcohol. Now comes the transformation: copper, steam, and some of the finest judgment calls in the drinks world.
Why Copper?
Whisky stills are made of copper for reasons far beyond tradition. Copper chemically neutralises the sulphur compounds created during fermentation, compounds that would otherwise bring harshness and rubbery, meaty notes into your glass. More copper contact means a cleaner, lighter spirit; less contact means a heavier, more characterful one. Distilleries also maintain their copper obsessively, because oxidised, tired copper stops doing its job.
First Distillation: The Wash Still
The wash goes into the largest still in the house, the wash still — and is heated. Alcohol boils at 78.37°C, lower than water, so it evaporates first, carrying flavour compounds with it. The vapour rises, condenses, and what flows out is called low wines, roughly 20-25% alcohol. Stronger than wash, but still a long way from whisky.
Second Distillation: The Spirit Still and the Cut
The low wines move to the smaller, more delicate spirit still, and here the real artistry begins. The distiller divides the run into three fractions:
Heads (foreshots): the first vapours, volatile, aggressive, containing compounds you genuinely don't want, including methanol. Set aside for redistillation.
Hearts: the middle of the run, the pure, characterful centre that will become whisky. Only this fraction goes to the cask. (In rakı, we call this same prized fraction the göbek — the belly. Every distilling culture found the same truth.)
Tails (feints): the end of the run, heavy, oily, bitter. Also redistilled.
Deciding exactly when hearts begin and end — the cut points, is one of the most consequential choices in whisky making. A minute early or late, repeated over thousands of runs, defines a distillery's signature. New make spirit leaves this process at roughly 70-80% alcohol, and completely clear: all of whisky's colour comes later, from the cask.
The Shape of Flavour
Here's the beautiful part: two distilleries can use identical barley and identical yeast and still make completely different whisky — because of still shape.
The neck: tall necks, Glenmorangie is the famous example, create more reflux — vapours cooling and falling back for another round of distillation, producing light, delicate spirit. Short necks, Macallan, let heavier compounds through: richer, oilier whisky.
The lyne arm: the pipe carrying vapour to the condenser. Angled upward, it sends heavy vapours back, lighter spirit. Angled downward, everything rushes through — bolder spirit. Horizontal sits in between.
The condenser: traditional worm tubs give minimal copper contact and a heavier, meatier character, while modern shell-and-tube condensers give more contact and cleaner spirit. wrote a full deep-dive on this: Worm Tubs vs Shell & Tube Condensers.
Still shapes even have names: onion, plain, straight, ball, lantern, and distilleries are so superstitious about them that when a still is replaced, every dent is faithfully copied.
Two, Three, or 2.81 Times?
Scotch single malt is typically distilled twice. Irish whiskey traditionally goes three times — wash to low wines, low wines to feints, feints to new make at 80-85% — which is a big part of that famously smooth Irish profile. See it at scale in my Midleton visit story.
And then there's Mortlach, which runs a gloriously eccentric 2.81 distillation across six different stills, blending fractions into something meaty and intense. Is the number partly marketing? Perhaps. Does it work? Absolutely.
Then, the Long Sleep
The clear new make spirit is filled into oak, and time takes over, years of breathing, expanding into the wood in summer, contracting in winter, slowly borrowing colour and character. But the cask story is so rich it has its own chapter: read The World of Casks: American, European, Japanese & Sizes for the full journey from ASB to Mizunara.
Next in the series: Scotch and Irish whiskies — regions, styles, and how to tell them apart.
Want to taste the difference still shape makes? Compare a delicate Glenlivet against a robust pot-still Redbreast using my tasting method. Join the Around The Glass Society to get the next chapter first.
