I recently flew from London to Istanbul and back on British Airways to test the flavours of food and wine at high altitude with a journalist from Women’s Health. Many factors affect the appreciation of wine at 9000 metres, but wine buyers for the airlines are becoming skilled at selecting those that work well in flight.
How do they do it, and what are the principles underlying success and failure?
Wines are greatly affected by cabin pressure, as I found out when drinking the same wines in the lounge and in the air.
When flying at high altitude, the dry atmosphere - which greatly reduces our ability to perceive aroma - low cabin pressure, cold temperatures and vibrations mean that even the best wines may not perform as expected.
In addition, white noise in the ears suppresses the tongue’s ability to detect basic tastes such as sweet and salty.
At about 80 decibels – the level of noise on board a commercial aircraft in flight – the effect on sweet and salty is quite marked.
This may be one reason why passengers complain about in-flight meals, despite the efforts some airlines have put into improving the food. The solution is to wear noise-cancelling headphones, which will do a lot to revive your palate and your wine.
But even with the headphones, wines are greatly affected by cabin pressure, as I found out when drinking the same wines in the lounge and in the air. Under low pressure, the molecules are more diffuse, meaning they have less impact on the olfactory receptors in the nose. Fruitier wines tend to fare better, and the more austere, noble wines passengers expect to find on the first-class wine list may not show well at all. Firm tannins in prestige wines tend to dominate at cabin pressure, leaving them dry and fiercely bitter.
The white choice
Andy Sparrow, of wine merchants Bibendum, is responsible for buying wine for British Airways’ first-class list. To find out which worked and which didn’t, he led a long-haul tasting for wine writers.
Sauvignon blanc, with its primary aromas and fresh acidity, was favoured among the whites and you will always find it on the BA list. Many of the more sought-after wines simply failed to deliver but, to everyone’s surprise, a malbec that people did not comment on when tasted on the ground suddenly came into its own at 9000 metres.
What should you look for when flying? Champagnes tend to work well and so does cava, and this may be due to the presence of carbon dioxide in the bubbles. This is a stimulant for the trigeminal nerve that serves the nose, eyes and mouth, and makes our nose tingle when we eat too much mustard. Trigeminal stimulation is not only immune to the effects of cabin pressure – which is why passengers often enjoy spicier food when they are flying – but it also boosts our perception of aroma.
Drinking champagne throughout the meal may help you to taste more of both.
One red to rock them all
Red wines, on the other hand, remain a problem. Bitterness is accentuated at altitude and, since astringency reinforces bitterness, it is best to avoid overly-tannic wines. On the other hand, malbec worked well.
What’s the explanation?
Many of Argentina’s most highly regarded malbecs are produced at very high altitudes. The cabins of planes flying at 9000 metres are pressurised as if one was at an altitude of 1800 metres and the famous Argentinean winemaker Nicolas Catena’s Zapata grapes are grown at 1740 metres.
Could it be that wines made at high altitude also perform better in those conditions?
More testing would need to be done, but next time the trolley comes round, ask for a high-altitude wine. If it works, remember, you heard it here first.
Barry Smith is director of the Institute of Philosophy, University of London.
New York Times