Baking a Cake at Altitude

I’m baking a cake in my mountain chalet (2500m altitude) using my usual recipe. Is this a good idea? And what changes may I need to make?

When baking a cake, a series of chemical reactions occur. These reactions transform the cake batter from a liquid into, a solid foam colloid.

At 2500m altitude, the atmospheric pressure is lower, which means that the air is less compressed. The air is described as being thinner, as there are fewer molecules in the air, including less oxygen and water molecules.

This lower atmospheric pressure affects the chemical processes of baking a cake, so adjustments need to be made to the recipe to compensate for this.

The main problems we have to overcome are:

* Reduced moisture in the air, this causes moisture in the cake batter to evaporate quicker.

* Lower air pressure, does not give resistance to the raising agent, meaning the cake will rise much higher and faster than when baked at sea level.

It is necessary for adjustments to be made to a sea level recipe when it is baked at altitude (Appendix A).

If the recipe is not adjusted the following faults that may occur:

1. The cake would rise in the oven and spill over the sides of the tin. It is advisable to use a larger tin, when baking at altitude, and to ensure the batter does not fill more than half of the tin.

2. The cake will rise excessively in the oven, the cell structure of the cake will be weakened and the cake will collapse when it comes out of the oven. This is known as an “M Fault”, because a cross-section of the cake is similar to a letter M.

3. Any moisture in the cake batter will evaporate quickly; this means the cake would be dry and crumbly, with a weak cell structure.

Baking Temperature and Time

We have increased the baking temperature by 14°C, this will set the batter and form a strong cell structure, before the cake has chance to rise excessively and develop a weakened cell structure. The baking time has been reduced by 20% to...