Tea at 90˚C
One drink you might be served on board your flight could be a little disappointing—and not just because you might have to drink it out of a plastic cup. That’s a nice cup of tea. Tea enthusiasts like their tea made with boiling water—which means getting the water up to 100˚C [212˚F]. That’s never going to happen on a plane. Not because the cabin crew can’t be bothered to do it properly, but because it’s impossible to get water up to 100˚C on board the aircraft.
At the pressure of an aircraft cabin—the equivalent of being up to 8,000 feet above sea level—water boils at around 90˚C [194˚F], and that’s as hot as your tea is going to get.
Imagine if you had one of the water boilers from the galley on the wing of the aircraft. A cup of tea made with this water would produce a very unappetizing drink. With the reduced air pressure at around 40,000 feet, water boils at just 53˚C [127˚F].