Heads, Hearts, and Tails: The Art of the ‘Cut’ (Whisky Distillation Cuts)

Distilling whisky is not as simple as boiling beer and collecting the steam. If you drank everything that came out of a pot still, you would likely go blind, suffer the world’s worst hangover, or vomit.

The liquid that flows from the condenser is a chaotic mixture of chemical compounds. Some are fruity and delicious. Some smell like nail polish remover. Others smell like wet cardboard or sweaty gym socks.

The job of the Stillman is to separate the good from the bad. This process is called making the Whisky Distillation Cuts.

It is the most critical moment in the production of spirits. It requires splitting the flow into three distinct parts: the volatile Heads, the sweet Hearts, and the oily Tails.

In this guide, we are going to explore the chemistry of boiling points and how a split-second decision determines whether a spirit becomes premium scotch or industrial cleaner.

1. The Physics: Boiling Points

Distillation works because different alcohols boil at different temperatures.

The “wash” (the beer-like liquid being distilled) contains water, ethanol, and hundreds of other congeners (flavor compounds).

• Methanol: Boils at 64.7°C (148°F).
• Ethanol (Drinking Alcohol): Boils at 78.4°C (173°F).
• Water: Boils at 100°C (212°F).
• Fusel Oils: Boil at higher temperatures, usually above 85°C.

As the still heats up, the compounds with the lowest boiling points turn into vapor first. This means the liquid coming out of the condenser changes chemically over time. It starts toxic, becomes drinkable, and eventually turns foul.

2. The Heads (Foreshots): The Poison

The first liquid to flow from the still is known as the Heads (or Foreshots in Scotland).

Character: High strength (80%+ ABV), solvent-like, pungent.

Compounds: Methanol, Acetone (nail polish remover), Acetaldehyde.

This liquid is dangerous. Methanol is toxic and can cause blindness. Acetone is unpleasant. Therefore, the distiller must divert this flow away from the spirit receiver.

However, the Heads are not thrown away. They still contain a lot of ethanol. They are collected in a separate tank and recycled into the next batch to be distilled again.

3. The Heart (Middle Cut): The Gold

After the volatile Heads have boiled off, the temperature in the still rises slightly, and the character of the spirit changes. The harsh solvent smell disappears, replaced by sweet, fruity aromas.

This is the Heart (or Middle Cut).

Character: Clean, fruity, floral, grassy.

Compounds: Mostly Ethanol and Esters (fruit flavors).

This is the only part of the run that goes into the cask to become whisky. The Stillman switches the flow using the Spirit Safe to capture this liquid. For most Scotch distilleries, the “Heart” starts when the spirit drops to around 75% ABV and ends when it drops to around 60% ABV.

How does the Stillman make the switch?
Read about the Spirit Safe mechanism (Vol 134).

4. The Tails (Feints): The Funk

As the distillation continues and the alcohol percentage drops below 60%, the liquid starts to get cloudy and heavy. These are the Tails (or Feints).

Character: Oily, waxy, vegetable, sweaty, rubbery.

Compounds: Propanol, heavy Fusel Oils, Phenols.

While you wouldn’t want to drink pure Tails, they are vital for flavor. They provide the “bass notes” of the whisky—the texture, the waxiness, and the smoke.

If you cut the Hearts too early, you lose these heavy oils, and the whisky feels thin. If you cut too late, the whisky smells like wet dog. It is a delicate balance.

5. Wide vs. Narrow Cuts

The timing of the Whisky Distillation Cuts defines the “House Style” of the distillery.

• Narrow Cut (Short Heart): Used by distilleries like Glenmorangie. They only collect the very purest, lightest part of the run (high esters). This creates a delicate, floral spirit.
• Wide Cut (Deep Heart): Used by distilleries like Laphroaig or Caol Ila. They let the distillation run longer into the Tails to capture the phenols (smoke) and oily compounds. This creates a heavy, rich, meaty spirit.

Want to taste the difference?
Learn how condensers also affect oiliness (Vol 113).

Summary: The Stillman’s Art

Distillation is science, but the “Cut” is art.

Deciding exactly when to switch the handle from Heads to Hearts, and Hearts to Tails, requires intuition and experience.

The next time you enjoy a complex single malt, remember that it exists in a narrow window between poison and funk. That purity is the result of the cut.