Cook spaghetti a minute or two longer at altitude

Yes, you need to add time—about 1-2 extra minutes.

At high altitude, water boils at a lower temperature (roughly 2°F lower per 1,000 feet). So your spaghetti is cooking at, say, 205°F instead of 212°F. That means less heat energy transferring to the pasta, which means slower starch gelatinization. Result: you need more time in the pot.

Don’t just blindly add minutes, though. Start checking at the package’s al dente time, then every 30 seconds after. At 5,000 feet, I usually add 90 seconds. At 8,000+, bump it to two or three minutes.

Also: use a bigger pot with more water. High altitude makes water evaporate faster, and if the concentration of starch gets too high, pasta will stick together. Salt the water generously—same as sea level—and stir a few times early on.

Oh, and don’t forget to taste-test. That’s always the real answer.

Set a timer, but trust your teeth.