Why does whisky sting the nose?

It is a feeling. Ethanol in the vapour above the glass activates the sensory nerve of the face and nose. Smelling and feeling are two separate systems.

In the specialist literature on taste and smell, three independent systems are distinguished: taste, smell and chemical irritation. Alcohol is explicitly named there as a source of a burning sensation. That is in the review article Chemosensory Factors Influencing Alcohol Perception, Preferences, and Consumption from Alcoholism: Clinical and Experimental Research.

That it is separate from smell can also be measured. Cometto-Muniz and Cain determined the threshold for irritation in the nose in people without a sense of smell. They do feel the irritation, although they smell nothing. The irritation therefore enters via a different nerve than the smell.

In practical terms that means: what you feel in the nose says nothing about the quality of the whisky. It says something about the amount of alcohol in the vapour at that moment.

TRPV1, the same receptor that responds to capsaicin from peppers and to heat. That is why the sting feels like warmth or sharpness and not like an aroma.

Trevisani and colleagues showed that in 2002 in Nature Neuroscience. Ethanol activates sensory neurons in the trigeminal ganglion, and cells that carry the receptor respond to increasing amounts of ethanol to an increasing degree. If you block the receptor, the response disappears.

The same study gives a sharp number. Normally that receptor only opens at about 42 degrees Celsius. With ethanol added it already opens at about 34 degrees. Body temperature is then enough, and that explains why alcohol comes across as warm or burning.

So it is literally the same route as with a chili pepper. Your nose is not doing anything strange; it reports a stimulus that it reads as heat.

Because the tingling moves with the amount of alcohol in the vapour. The higher the percentage in the glass, the more ethanol reaches the nose and the stronger the sensation.

At the bottom there is a legal limit. Regulation (EU) 2019/787 prescribes at least 40 percent alcohol for category 2, whisky or whiskey, and the Scotch Whisky Regulations 2009 do the same for Scotch. Anything lower may not be placed on the market.

There is no limit at the top. Cask strength is whisky bottled without dilution, and according to the research by Karlsson and Friedman in Scientific Reports it usually lies around 59 percent.

In the whisky department in Bathmen, 3,898 items, that difference is easy to see. There are 957 bottles at 40 to 43 percent, from 315 brands from 23 countries. In the cask strength range of 55 percent or more there are 809 bottles from 204 brands, with 73.7 percent as the highest percentage. That last glass bites incomparably sharper than the first.

Yes. Water lowers the alcohol percentage in the glass and thereby in the vapour. The Scotch Whisky Association advises in its tasting toolkit a little still water that is not chilled.

Karlsson and Friedman used molecular simulations to calculate what happens on dilution. Guaiacol, one of the smoke aromas, stays mainly at the interface of liquid and air up to about 45 percent by volume of ethanol. Above 59 percent it draws into the liquid. If you dilute cask strength, it therefore ends up sooner in the place where you can smell it.

The same advice comes from the other direction. Wang and Cadwallader showed in Beverages that more ethanol in the vapour raises the threshold above which aroma compounds are first noticed, and that this threshold rises with the percentage in the liquid. Diluting is therefore not doing the whisky a disservice, but making room for the aroma.

Do it step by step. A few drops, smell again, and only add more if it is still too sharp. There is no going back.

A tulip shape with a narrow rim concentrates the vapour and sends it straight to the nose. A glass with a wide rim lets the vapour fan out, so that the prickle arrives more gently.

The Scotch Whisky Association describes the tulip glass in exactly this way: the tulip shape lets the aromas gather in the glass, and the glass is meant to guide those aromas to the nose. For finding fine aromas, that is an advantage.

The same bundling applies to the alcohol. A technical article in Beverages from 2018 sets the rim dimensions side by side: a copita has an inner rim of about 40 millimetres, a Glencairn about 45 millimetres, and a snifter or tumbler about 80 millimetres. According to that article, the narrow, inward-tapering rims concentrate the ethanol above the rim.

So there is a choice to make. If you are looking for the details, take the tulip glass. If it stings too much, pour the same drink into something with a wider rim and smell again.

Hold the glass a few centimetres below the nose instead of at it, keep your mouth slightly open and smell in short sniffs. Put the glass down for a moment in between.

That method is described in Whisky Magazine, where Ian Wisniewski describes his own routine. He keeps his mouth open while nosing, and holds the glass a few centimeters below his nose to check that he is getting aroma and not alcohol.

Pausing also makes sense. The technical article in Beverages refers to a recovery time of about 200 seconds, a little over three minutes, for some 70 percent recovery after habituation. A nose that has just had a cask strength whisky does not reveal much directly afterwards.

Komt u langs aan de Brink in Bathmen, dan leggen wij u graag naast elkaar wat een fles op 43 procent en een fles op 60 procent in de neus doen. Wij verkopen geen alcohol aan personen onder de 18 jaar, NIX18.