why do altitudes matter when using an oven?


Like why is that even a factor??? It’s an oven? Gravity??

In: Chemistry

You cannot heat water above its boiling temperature.

Water boils at a lower temperature when the air pressure is lower.

The air pressure is lower at higher altitudes.

The temperature of boiling water is lower at higher altitudes.

Many recipes cooking times are reliant on boiling water, and if at a higher altitude you’ll need to increase this time.

Altitudes matter for ovens because ovens cook food by heating up air. There is less air at higher altitudes, and less air means less hot air to cook with.

It changes the temperature at which water boils. The water boils at a lower temperature, so it’s boiling but not AS hot as boiling at lower altitude.

For baking cakes and other things that rise, the lower pressure causes them to rise faster and earlier during the bake, becoming very airy and then collapsing ad becoming a very dense cake.

Density of the air is the big one. The higher the altitude the lower the density and as such the slower the heat transfer will ultimately be. Water also boils at a different temperature because as the air density decreases so does the air pressure which changes the temperatures required to boil water.

Most stuff that you bake contains a lot of water, and as long as that water is there, the inside of the food can’t be hotter than the boiling point of the water, even if the oven is set to a higher temperature.

The boiling point of water depends on the air pressure, and the air pressure depends on the altitude, so at higher altitudes you will need longer baking times to compensate.

The key term is probably latent heat – the amount of energy needed for a phase change (solid > liquid > gas & vice versa).

At standard pressure (1 atm) water has a boiling point of 100 °C. This changes as pressure increases and decreases. This is why many materials state ‘at STP’ or Standard conditions for Temperature and Pressure