Why can't you make a proper cup of tea on Mount Everest?

Answer 1

If you made the tea on top mt Everest the water used would have boiled at a lower temperature! Which would effect the taste of the tea and what molecules are extracted

"The best temperature for brewing tea depends on its type. Teas that have little or no oxidation period, such as a green or white tea, are best brewed at lower temperatures, between 65 and 85 °C (149 and 185 °F), while teas with longer oxidation periods should be brewed at higher temperatures around 100 °C (212 °F).[54] The higher temperatures are required to extract the large, complex, flavorful phenolic molecules found in fermented tea, although boiling the water reduces the amount of dissolved oxygen in the water."

Keeping in mind that oxidation and oxygen play a role in tea, "thinner" air on top mt Everest results in less oxygen present!

Answer 2

You can't make a proper cup of cup of tea on Mount Everest because the atmospheric pressure level is low (reducing water's boiling-point) and it's freezing up on Everest!