If you think the food airline companies serve up is bland or unappetising, it’s not necessarily their fault. Essentially, you leave your normal sense of taste behind at the airport departure gate. Get on board a plane and cruise to a level of thousands of feet, and the flavour of everything from a pasta dish to a mouthful of wine becomes manipulated in a whole host of ways that we are only beginning to understand.
Taste buds and sense of smell are the first things to go at 30,000 feet, says Russ Brown, director of In-flight Dining & Retail at American Airlines. “Flavour is a combination of both, and our perception of saltiness and sweetness drop when inside a pressurised cabin.”
Everything that makes up the in-flight experience, it turns out, affects how your food tastes. “Food and drink really do taste different in the air compared to on the ground,” says Charles Spence, professor of experimental psychology at Oxford University. “There are several reasons for this: lack of humidity, lower air pressure, and the background noise.”
Dryness and low pressure
When you step on an aeroplane, the atmosphere inside the cabin affects your sense of smell first. Then, as the plane gets higher, the air pressure drops while humidity levels in the cabin plummet. At about 30,000 feet, humidity is less than 12% – drier than most deserts.
The combination of dryness and low pressure reduces the sensitivity of your taste buds to sweet and salty foods by around 30%, according to a 2010 study conducted by Germany's Fraunhofer Institute for Building Physics, commissioned by German airline Lufthansa. To investigate this the researchers used a special lab that reduced air pressure simulating cruising at 35,000 feet (10.6km) – as well as sucking moisture out of the air and simulating the engine noise. It even made seats vibrate in its attempts to mimic an in-flight meal experience.
(Getty Images) (Credit: Getty Images)
(Getty Images)
Interestingly, the study found that we take leave of our sweet and salty senses only. Sour, bitter and spicy flavours are almost unaffected.
But it’s not just about our taste buds. Up to 80% of what people think is taste, is in fact smell. We need evaporating nasal mucus to smell, but in the parched cabin air our odour receptors do not work properly, and the effect is that this makes food taste twice as bland.
So airlines have to give in-flight food an extra kick, by salting and spicing it much more than a restaurant on the ground ever would. “Proper seasoning is key to ensure food tastes good in the air,” says Brown at American Airlines. “Often, recipes are modified with additional salt or seasoning to account for the cabin dining atmosphere.”
Gerry McLoughlin, executive chef at rival US airline United, says he has to use “vibrant flavours and spices” to make in-flight meals taste “more robust”.
He and his fellow chefs also have the constant loud humming of the jet engines to contend with. While you may think that flavour is influenced by your nose and mouth, psychologists are now finding that your ears can also play a part. (For more on this, see this video and try out a taste experiment) A study found that people eating to the sound of loud background noise rated food as being less salty and less sweet than those who ate in silence. Another twist: to those surrounded by noise, food surprisingly appeared to sound much crunchier.
However, a plane’s loud background noise of around 85db does not affect all tastes equally, says Spence. For example, seasonings like cardamom, lemon grass and curry taste more intense in the sky than salt or sugar.
Mass-produced recipes
It’s not just the in-cabin conditions that have to be taken into account. Preparing and serving tasty food for a few hundred people above the clouds is not an easy task. Because of food safety standards, all meals must be cooked on the ground. There the food is packed, blast-chilled, refrigerated, and finally must survive re-heating in the air. All of this would modify the flavour even if it was served at sea level.
To re-heat food on board, for safety reasons nearly all airlines use convection ovens, which blow hot, dry air over the food. Microwaves and open flames are not allowed, although the first induction ovens are now on the market.
(Getty Images) (Credit: Getty Images)
(Getty Images)
“Airline chefs are unique in that they mass produce recipes for thousands of customers,” says Brown. “Many times the final product is not what was originally envisioned due to things outside their control. We design food with ingredients and packing we know can survive the long process between food preparation and delivery.”
Recently fashionable ways of cooking like sous-vide – where the food is cooked in a sealed plastic bag for a long time at a relatively low temperature - also help making in-flight food taste better, says Pam Suder-Smith, president of the International Flight Services Association.
So to improve the quality of airline food, airlines a