During a long flight, seeing the beverage cart roll down the aisle can bring instant comfort to passengers — but flight attendants warn travelers to think twice before ordering.
Flight attendants from multiple major airlines have given the same warning throughout the years: Avoid getting a hot cup of coffee or tea during a flight.
The cabin crew members’ reasoning is that the water used for steaming hot drinks in the air is sourced from onboard water tanks that are not cleaned regularly, according to Southern Living.
Former flight attendant Kaz Marzo told the magazine: “I’ve personally witnessed maintenance crews neglect proper tank-cleaning protocols. The pipes also collect mineral buildup over time.”
Instead, flight attendants recommend ordering sealed, canned or bottled drinks to enjoy in the skies.
Another former flight attendant, Kat Kamalani, echoed the same warning in a TikTok video posted in 2021.
“Never consume any liquid that is not in a can or a bottle,” Kamalani said. “The reason being is because those water tanks are never cleaned and they are disgusting.”
She went on to claim that the actual coffee machines are “rarely cleaned unless they are broken.”
“The whole machine is never cleaned,” she added. “And they’re by the lavatories.”
Kalamani then said that parents should never put hot water from the plane in baby bottles due to potential bacteria. Instead, “ask for bottled water on the side and hot water in a cup, then make your baby a bottle with the bottled water and put it in the [hot] cup and heat it up.”
A three-year study on airline water quality published in December 2025 revealed that the advice might be worthwhile, depending on the airline.
Conducted by the Center for Food as Medicine and Longevity, the 2026 Airline Water Study ranked the quality of water from 10 major and 11 regional airlines.
Water from the airlines was ranked on criteria including violations per aircraft, Maximum Contaminant Level violations for E. coli, indicator-positive rates, public notices, and disinfecting and flushing frequency.
In the report, CFML director Charles Platkin wrote that Delta Air Lines, Frontier Airlines and Alaska Airlines had the “safest water in the sky.”
However, Platkin added that “nearly all regional airlines need to improve their onboard water safety.”
The Aircraft Drinking Water Rule, enacted by the federal government in 2011, requires airlines to provide safe drinking water to passengers and crew.
However, the CFML recommended never drinking water that has not been provided in a sealed bottle.