Welcome to brain Stuff from how stuff works dot com where smart Happens. Hi. I'm Marshall Brand with today's question, why do some foods have high altitude cooking instructions? Almost any packaged food that involves boiling, like boxed macaroni and cheese dinners, for example, will have high altitude cooking instructions. I have here in front of me a box of Hamburger helper that says high altitude thirty sixty feet, decrease hot water to three and three quarters cups and increase
the simmer time to seventeen minutes. So why would you want to increase the simmer time at altitude? The reason foods have these instructions is because the boiling point of water changes with altitude. As you go higher, the boiling temperature decreases, So at sea level, the boiling point of
water is two hundred twelve degrees fahrenheit. As a general rule, the temperature decreases by one degree fahrenheit for every five ft of altitude, So on top of Pike's Peak at fourteen thousand feet, the boiling point of water is only one seven degrees fahrenheit. So pasta or potatoes cooked at sea level are seeing twenty five degrees more heat than pasta or potatoes cooked on Pike's Peak. The lower heat means you need a longer cooking time. Pressure cookers work
in the opposite direction. A pressure cooker raises the pressure so that the water boils at a higher temperature. A typical pressure cooker applies fifteen pounds of pressure, so the boiling point of water rises to two hundred fifty degrees fahrenheit at sea level. The higher temperature means that foods take less time to cook inside a pressure cooker. Be sure to check out our new video podcast, Stuff from the Future. Join how staffork Staff as we explore the
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