Triple distillation explained
Most malt whisky is distilled twice. Triple distillation adds a third run, a tradition strongly linked with Irish whiskey and a few Lowland Scotch distilleries. Here is what the extra run does and how it shows up in the glass.
A third pass through the stills
Triple distillation runs the spirit through three pot stills instead of two. The first still takes the fermented wash of around 8% ABV and makes low wines. The second still takes those low wines and makes a stronger intermediate spirit. The third still redistils that intermediate spirit into new make. Each stage separates more alcohol from water and narrows the range of flavour compounds.
The new make from a triple distillation is usually collected at a higher strength than double distilled spirit, often in the region of 80% ABV or a little above. It still stays well below the legal limits for whisky in Scotland and Ireland, which require distillation to less than 94.8% ABV.
Where the method comes from
Triple distillation is strongly associated with Irish whiskey. Many Irish pot still and malt whiskeys are triple distilled. The tradition is part of how Irish whiskey is described. In Scotland, a small number of distilleries, historically many in the Lowlands, also triple distil. Most Scotch malt whisky is double distilled.
Irish whiskey must be distilled and matured on the island of Ireland. It must mature for at least three years in wooden casks. Triple distillation is a tradition, not a legal requirement for Irish whiskey. Our guide to single pot still Irish whiskey covers the Irish style built on malted and unmalted barley.
How the three stills share the work
The details vary by distillery, but the logic is consistent:
- Wash still. Strips alcohol from the wash. Low wines come off and are often split into a stronger and a weaker fraction.
- Intermediate still. Redistils the low wines. Its stronger cut goes forward to the spirit still and its weaker fractions are recycled.
- Spirit still. Makes the final cuts into foreshots, heart and feints. The heart becomes new make.
Some fractions loop back into earlier stills in patterns that differ from plant to plant. The result is a more selective process with more chances to separate light compounds from heavy ones. Our guide to distillation logs and what to record shows how a distillery keeps track of those loops.
What it does to flavour
A third distillation strips out more of the heavier, oilier compounds and more of the sulphur. The spirit also spends longer in contact with copper across three stills, which helps remove sulphur compounds. The new make is typically lighter, cleaner and more delicate than double distilled spirit, with floral, fruity and sweet cereal notes rather than oily or meaty weight.
That does not make it better or worse. A lighter spirit picks up cask character readily and can show a fresh, gentle style. A heavier double distilled spirit can carry more weight into long maturation. Our guide to double distillation explained sets out the other side of the comparison.
Triple is not the same as column
People sometimes assume that more distillations means a spirit is heading towards vodka. Not so. Each pot still run is a batch distillation with limited separation, so even three runs leave plenty of character. A column still separates far more sharply in one continuous run and can reach much higher strength. Triple pot still distillation sits between double pot still and column distillation in lightness, much closer to the pot still side.
Our guide to batch versus continuous distillation compares the two methods.
Tasting triple distilled whiskey
Triple distilled whiskey suits a slow, careful tasting. Pour about 15 ml in a tulip shaped glass. Nose it gently, because higher strength vapour can sting. Add a few drops of water and nose again: look for orchard fruit, honey, light cereal and floral notes. Then compare it with a double distilled malt from a similar cask type. Drink water, eat something alongside and never drink and drive.
Telling the stillhouse apart from the cask in a glass is hard at first. It gets much easier once you know what each stage adds, which is why we teach whisky from the grain up.
Your first comparison
Pick one triple distilled Irish whiskey and one double distilled malt whisky aged in similar casks, ideally ex-bourbon. Taste them side by side with water. Write down which one feels lighter on the palate and which one leaves more oily weight. You have just tasted the third still.
Common questions
What does triple distilled mean?
It means the spirit was distilled three times in pot stills, adding an intermediate run between the wash still and the spirit still.
Is all Irish whiskey triple distilled?
No. Triple distillation is a strong Irish tradition, but it is not a legal requirement. Some Irish whiskeys are double distilled or made in column stills.
Does triple distillation make whiskey smoother?
It usually makes a lighter, cleaner spirit by removing more heavy and sulphury compounds. Smoothness also depends on the cask and age.
How strong is triple distilled new make?
Triple distilled new make is often collected at around 80% ABV or a little above, higher than double distilled spirit.
