What does triple distilled mean?

With triple distillation the distillate passes through an additional still. Each run raises the alcohol percentage and removes part of the heavier aroma and flavour compounds.

With double distillation, the wash first runs through the wash still and then through the spirit still. With triple distillation a third still is added in between, and the heads and tails are distributed differently over the runs. The contact with copper is greater, so more sulfur compounds are captured. The whisky must still mature for at least three years in oak afterwards.

The stronger the distillate comes off the still, the lighter the aromatic character. Around 80 percent fewer heavy compounds remain than at about 70 percent.

Whisky Professor of the trade magazine Scotch Whisky explains that repeated distillation and more copper contact are mainly about removing heavy congeners. The result is usually a finer, more floral and less oily distillate. That is not automatic: Mortlach distils 2.81 times on average and yields a heavy, meaty and rich character. The shape of the stills and the cuts chosen weigh as heavily as the number of runs.

No. The Irish technical file names distilling three times as the traditional method, but expressly adds that distilling twice is also allowed.

The file literally states that the traditional practice is to distil Irish Whiskey three times, although this practice is not exclusive and double distillation may also be used. Elsewhere it says that tradition determines per distillery whether a three-stage or a two-stage process is chosen. What is binding: distilling to less than 94.8 percent, maturing for at least three years in wooden casks of up to 700 litres, and bottling at no less than 40 percent.

Yes. Auchentoshan in the Lowlands distils exclusively three times, and Springbank in Campbeltown does so for its malt Hazelburn.

At Auchentoshan the new distillate is cut at an average of 81 percent, considerably higher than with a usual double distillation. Springbank is special because three styles are made under one roof: Springbank with an intermediate form, Longrow distilled twice and Hazelburn three times. So triple distillation is not an exclusively Irish thing, and double distillation is not an exclusively Scottish thing.

Not by definition. Smoothness, in the sense of little burn in the finish, is linked to lighter congeners, but is also determined by the shape of the still, the cuts and the maturation.

A lighter distillate also picks up flavour from the cask more quickly, so the influence of the wood weighs relatively heavier. Mortlach shows that distilling more often and a heavy character go together perfectly well. So use triple distilled as an indication of the method, not as a promise about the flavour. If you want to know whether a bottle suits you, just ask in the shop.