For a complete answer, see:
http://www.highaltitudebaking.com/science.htm
or order the book:
Pie in the Sky, by Susan Purdy The short answer is that at high altitudes: (1) Water evaporates more quickly because water boils (ie turns into steam) at a lower temperature, and (2) Anything involving air, like leavening (rising), behaves differently at altitude because there is less air and lower air pressure. You add extra water because... During the baking process, which means warming from room temperature to final baking temperature, more water will leave (steam off) a high-altitude cake. The extra water compensates for this. You add extra flour because... The lower air pressure will cause the cake to rise too much and too quickly, and can also cause the cake to "fall" afterward. I believe the extra flour slows the rising process. Ideally you would "take out" some of the leavening, but in a boxed mix you can't do that, so by increasing the flour you cause roughly the same effect (reduce the leavening-to-flour ratio). For lots of good data about this see:
http://www.highaltitudebaking.com/science.htm
Lower air pressure at high elevations causes air bubbles trapped in the batter to rise at a faster rate. When this happens, cakes rise very fast and high . . . then fall. As a result, you end up with a dense, dry cake--typically, a change in the proportion of ingredients used in leavened foods is needed. Occasionally, you may even need to adjust the baking temperature in your oven as well, but this can start a chain reaction of additional problems. When you increase your baking temperature, liquids will evaporate faster and the rest of the ingredients become concentrated. Generally, this means you end up with too much sugar in the batter, which will prevent the cake from setting (i.e. you will be left with a gooey mess).
Good question. It is because of atmospheric pressure, the air is less dense at higher elevations so time increases at a given temperature. Water boils at 212° F. sea level but boils at a lower temperature the higher you go in elevation, the air is less dense, hence the water molecules (H2O) are spaced further apart and require less energy to reach the gaseous state.
A related thing is that recipes (particularly baked goods) require additional liquid because their massis less.
Want to talk about mass, weight, and volume?
;-)
Higher elevations contain different pressures (particularly air pressure) than at sea-level. There are also some temperature differences that may occur. Both of these would change the bake time of cakes.
because at higher elevations there is less pressure and sea level has more pressure
No. Usually commercial recipes are written with sea level in mind but if you are above sea level 4,500ft or more you need to consider a longer cooking time
Cakes are baked where ever people live and wish to eat cake, including at high altitudes.
No, it's quicker.
True
altitudes
They have cooler temperatures than places at lower altitudes.
They have cooler temperatures than places at lower altitudes.
differing altitudes
high altitudes indicate cold temperatures so then that means that water vapor condenses at cooler temperatures and when water vapor condenses then it creates clouds
1oo degrees 1oo degrees
The air is essentially warmed when solar energy reaches the ground and is converted to heat. The further you get from the warming effects of the ground the colder the air gets.
Cloud structures vary at different altitudes due to different levels of air pressure. There are several scientifically recognized altitudes of atmosphere.
No, there is no need to alter normal baking methods at sea level. Special considerations are needed at high altitudes, not low altitudes.
yes i does
No.