You may think all beverages are equally bad on a plane, but it turns out one type of drink is extra irksome to your cabin crew.
Diet Coke is difficult to pour in the sky because it foams up more than non-diet drinks, according to a recent post on the flight attendant blog These Gold Wings.
We checked with other flight attendants, who confirmed the struggle is real. Among them was Heather Poole, an American Airlines flight attendant who wrote about the phenomenon in a 2012 article for Mental Floss.
“[Diet Coke is] the most annoying beverage a flight attendant can pour for a passenger in flight, because in the time it takes us to fill one cup, we could have served an entire row of passengers,” Poole wrote. “I’ve actually had nightmares about frantically trying to finish a never ending Diet Coke beverage service before landing.”
Pouring the drink is such a struggle that These Gold Wings demonstrated a “smart way” to avoid all the fizz in a 2013 video:
Many soda fans note Diet Coke is fizzier than regular Coke even on the ground, theorizing that its lack of sugar makes for a less viscous liquid, allowing bubbles to last longer before popping.
A Coke spokeswoman declined to share scientific specifics with HuffPost, but hinted that Diet Coke’s ingredients could be the cause of its extra bubbles. Pouring the drink over ice only increases fizziness.
“The amount of bubbles across different sparkling beverages is related to the specific recipe versus the altitude in which they are poured,” the spokesperson told HuffPost. “Generally, when sparkling beverages are poured at room temperature from a can and over ice, the fizz is increased.”
According to Southwest Airlines flight attendant Stephanie Mikel, the effect occurs in all diet drinks.
“Any diet or zero calorie soda fizzes more than the regular kind,” she told HuffPost. But “obviously, if it’s something someone wants, I would never get upset over that. You learn quickly which [sodas] you need to pour from a high angle and slowly.”
Some airlines hand out entire cans of soda, Jay Robert of Fly Guy noted (and you might even score one on a non-can airline, if you ask nicely.) With luck, you’ll be able to experience this phenomenon for yourself!