Why Nothing Tastes Right at 35,000 Feet

Almost everybody has an opinion about plane food, and almost nobody has a good one. The chicken is dry, the sauce is strange, the whole meal tastes of very little. What makes this odd is that most of it was cooked by trained cooks, in a proper kitchen, on the ground. Something happens between the kitchen and the tray, and most of it happens to you rather than to the food.

Three things are working against your dinner.

The first is dry air. The air in a cabin is far drier than the air in any room you have ever lived in, and drier than most deserts. Within about twenty minutes your nose has dried out, and a dry nose smells less. Since most of what we call flavour is really smell, the meal has lost a good part of its taste before the trolley has even left the front of the plane.

The second is pressure. A cabin is kept at a pressure closer to a mountain than to sea level, and at that pressure the tongue becomes noticeably worse at two tastes in particular: sweet and salty. In tests, passengers have needed around thirty per cent more sugar or salt to get the effect they would get at home. Sour, bitter and spicy are hardly reduced at all. That is why a lemon dessert or a hot curry survives a flight better than a sandwich does.

The third is noise. The cabin runs at about eighty-five decibels all through the meal, roughly the level of a busy road. Sweetness is pushed down further by that noise, while savoury tastes, the deep meaty ones, seem to be pushed up by it.

This explains the tomato juice. On the ground it is a drink almost nobody orders; in the air it is one of the most popular things on the trolley, and one large German airline has reported serving nearly as much tomato juice as beer. Tomato juice is savoury and slightly sour, which are exactly the two things the cabin cannot take away.

Airlines have known all of this for years, and they cook accordingly. Aircraft meals are seasoned far more heavily than restaurant food: more salt, more sugar, more acid, and ingredients chosen because they are naturally savoury, such as tomato, mushroom, soy sauce, hard cheese and cured meat. A sauce that tastes delicious in a kitchen on the ground will taste of almost nothing at altitude, so menus are tested in low-pressure rooms before they are ever loaded onto a plane.

Which leads to an uncomfortable conclusion for anybody who complains about the tray. That meal was never designed for your kitchen table. It was designed for a mouth that cannot taste properly. Carry the same tray home, sit down in normal air and normal quiet, and you would not finish it. It would be far too salty. It would taste of almost nothing else.