Why Does This Whisky Taste Like That? Part 4: Does the Shape of a Still Really Matter?
Imagine giving two chefs the same ingredients and asking them to make the same meal. Chances are, the results would be completely different. The same is true in whisky. Two distilleries can use the same barley, the same water, the same yeast and even ferment for a similar length of time. Yet the spirit they produce can taste radically different.
One reason lies in a piece of equipment that's really become the visual icon of Scotch whisky: the copper pot still. You might think that all stills look fairly similar; a bulbous pot, a tall neck and a swan-like lyne arm stretching away towards a condenser. But look more closely and you'll notice that no two are quite the same. And those differences matter.
More than just a vessel
After fermentation, the liquid, known as wash, is a bit like a strong, hoppy beer, usually around 7–9% alcohol. Distillation concentrates the alcohol, but it also shapes the character of the spirit.
As the wash is heated, alcohol and other volatile compounds evaporate and rise through the still. As they travel upwards, some vapours make it all the way through to the condenser while others cool, condense and fall back into the still. This process is known as reflux.
The more reflux that occurs, the more opportunities there are for heavier compounds to remain behind, allowing lighter, more delicate vapours to continue their journey. The result is often a lighter, more elegant spirit. Less reflux generally allows more of those heavier compounds to pass through, producing a richer, weightier character. It's a bit like filtering coffee. Small changes to the process can produce surprisingly different results.
Why copper matters
The material of the still is just as important as its shape. Scotch malt whisky must be distilled in copper pot stills. But copper does far more than conduct heat. As spirit vapours pass over its surface, copper helps remove unwanted sulphury compounds, resulting in a cleaner, fruitier and more refined spirit.
It's one reason why stills require such careful maintenance. As the copper gradually wears away over decades of use, distilleries often go to extraordinary lengths to recreate replacement stills to the exact same dimensions. They're not just preserving equipment, they're protecting the character of their whisky.
The art of choosing what to keep
Not everything produced during distillation ends up in the bottle. As spirit flows from the still, the distiller divides it into three parts: the foreshots, the heart/spirit and the feints. Only the heart cut is collected to become Scotch whisky. The foreshots contain compounds that are generally too volatile, while the feints include heavier components that can overwhelm the spirit.
Exactly when a distillery begins and ends that heart cut is one of the most closely guarded decisions in whisky making. Move those cut points by only a few minutes and the character of the spirit can change noticeably. It's another reminder that making whisky is as much about judgement as it is about science.
Three distilleries, three distinct styles
If you want to experience the influence of distillation, these whiskies provide fascinating comparisons.
Glenmorangie: Glenmorangie is famous for having some of the tallest stills in Scotland. The increased reflux helps create the distillery's elegant, floral and citrus-led house style.
The Macallan: The Macallan takes a very different approach. Its smaller, squat stills encourage a richer, fuller-bodied spirit, providing the weight needed to stand up to intensive sherry cask maturation.
The Dalmore: The Dalmore uses stills of different shapes and sizes within the same distillery, allowing it to produce a spirit with its own distinctive balance of richness and complexity.
Each distillery is making deliberate choices long before their spirit reaches a cask.
The real lesson
It's tempting to think of distillation as simply separating alcohol from water. In reality, it's one of the most creative stages of whisky production - the size of the still, its shape, the amount of copper, the way it's heated and the precise moment the heart cut begins and ends. Each decision nudges the spirit in a different direction. And that's why two distilleries working with remarkably similar ingredients can create whiskies that taste nothing alike.
Next time, we'll arrive at the stage most people associate with whisky flavour: maturation. Because while the cask has an enormous influence, it doesn't work alone and understanding what really happens inside a barrel may challenge another common assumption.
