Why Coffee on Airplanes Tastes So Bad (And Why Espresso Machines Aren’t Allowed Onboard)

 I’ve talked before about “coffee on airplanes,” and anyone who’s been on a long-haul flight knows the feeling—at some point, you just want a decent cup of coffee to stay awake. Unfortunately, what you usually get onboard is instant coffee, to the point where most people have completely given up hope.

For a long time, I assumed this was simply airlines trying to cut costs, or maybe a result of limited cabin space that made it impossible to install proper coffee machines. Either way, I never felt I had a truly convincing explanation. Carrying that bias with me, I eventually started digging into the topic. After looking into the details, I finally found some solid reasons that answered a question I’d wondered about for years. So today, let’s talk about why it’s basically impossible to brew fresh coffee with a coffee machine on an airplane.

I’m sure many people share this professional—or at least emotional—curiosity. The idea of sipping a freshly brewed coffee at 35,000 feet sounds incredibly pleasant. But the reality is that the absence of onboard espresso machines isn’t due to a single limitation. It’s the result of multiple factors working together. Once you understand them, instant coffee on your next flight suddenly feels a bit more forgivable—at least in theory.

The first and most decisive factor is safety. High-quality espresso machines require enormous bursts of power to heat their boilers and drive high-pressure pumps. Aircraft electrical systems are designed primarily for avionics and low-power passenger devices like phones and laptops. They simply aren’t built to handle the massive power draw of commercial espresso machines. Forcing such equipment into the system could cause circuit overloads, power failures, or even fire hazards.

On top of that, espresso relies on high-pressure extraction. Although aircraft cabins are pressurized, the pressure still corresponds roughly to an altitude of 2,000–2,500 meters (about 6,500–8,200 feet). In this environment, water boils at a lower temperature—around 90°C (194°F). That alone affects extraction efficiency and leads to subpar flavor. More critically, the pressure difference between the inside of an espresso machine and the lower ambient cabin pressure places extreme demands on seals and internal components, significantly increasing the risk of leaks or mechanical failure.

Espresso machines also involve heating elements, hot water, and high-temperature steam—all of which are inherent fire risks. In flight, a fire is far more dangerous and far harder to manage than on the ground. Add turbulence into the mix, and the risk increases even further. A heavy machine filled with near-boiling water and pressurized steam would have to be secured perfectly. If it tipped over, the consequences could be severe. The commercial espresso machines we see in cafés simply aren’t designed with high-altitude operation or in-flight conditions in mind, which makes them fundamentally unsuitable for aircraft use.

Then there’s the very practical issue of time and service efficiency. Even on long-haul flights, cabin crews may need to serve hundreds of passengers. Pulling a single espresso shot takes only a few dozen seconds, but the full process—grinding, dosing, tamping, extracting, and cleaning—takes much longer and requires specialized training. There’s simply no way to spend several minutes making coffee for each passenger without severely slowing down overall service. Even if this were limited to first-class cabins, it still wouldn’t solve the safety and technical issues mentioned earlier.

Space and weight are also critical considerations. Every inch of cabin space and every kilogram onboard directly affects fuel efficiency. A commercial espresso machine, along with a grinder, water connections, and drainage, would take up a significant portion of galley space. By comparison, the hot water boilers currently used on aircraft, along with pre-ground coffee or coffee packs, are vastly more efficient in both space and weight.

Water quality is another factor. While aircraft water tanks meet hygiene standards, their mineral content and taste differ from properly filtered water used in cafés. This alone can negatively affect coffee flavor. Installing a dedicated water filtration system just for coffee would be highly impractical.

Even if we take a step back and imagine that an airline somehow managed to serve you a café-quality espresso in the air, you still probably wouldn’t experience its true flavor. This brings us to the passenger’s perspective: why does coffee taste worse on a plane in the first place? Altitude changes how we perceive flavor. Cabin air reduces our sense of smell, and taste sensitivity can drop by as much as 30%. Acidity becomes harder to detect, sweetness is muted, and bitterness tends to stand out more.

High altitude also brings other physiological effects—bloating, pressure changes, dehydration, and reduced energy levels—all of which influence sensory perception. On top of that, the lower cabin temperature means hot coffee cools down faster than it would on the ground, further degrading the experience.

That’s why the most common coffee you see onboard today is drip coffee. Flight attendants typically load large bags of pre-ground coffee into specialized drip machines on the ground, add hot water, brew a full pot at once, and then serve it to passengers. Some airlines take things a step further by using coffee capsules. A few premium carriers have introduced capsule systems similar to Nespresso. These machines are simpler in structure, require less power, and are easier to operate, while delivering more consistent flavor than drip coffee. Even so, they’re specially designed or rigorously certified for aviation use and differ from standard ground-based models.

Some people might ask: if espresso is impractical, what about hand-brewed pour-over coffee? In reality, the same issues apply. Even without a large machine, pour-over still requires grinding, dedicated workspace, and extra time. From a service perspective, it’s simply not a viable way to quickly serve passengers during a long flight.

When you look at all of this together, it becomes much easier to understand why good coffee is so hard to come by in the air. The problem isn’t that it’s technically impossible—it’s that safety, efficiency, and economics all outweigh the pursuit of better flavor. At 35,000 feet, safety and reliability will always come first. As for truly good coffee, it’s probably best enjoyed after landing, when you can seek out a local specialty café and let your taste buds work the way they’re meant to.