Baking at high altitudes will require some adjustments to ingredients, temperature, and baking time. If you are below 3000 feet in altitude, you do not have to make any adjustments, but any place at or above 3000 feet will require some changes to your baking procedure. The reason such high altitudes require changes in baking is because the air pressure is so much lower. This has to do with atmospheric pressure. Since there is less air at high altitudes, there is less pressure pushing down on everything. This lower pressure causes baked items to rise faster, since the weight of the atmosphere does not impede rising as much.
So, some of the changes have to do with preventing a cake or other baked item from rising too rapidly.
See Pie in the Sky, Your High Altitude Baking Book
Also, food stored at high altitudes dries out faster than foods stored at sea level. Therefore, dry ingredients like flour will have less moisture. This may require more liquid to be added to get the desired consistency of batter or dough.
In a perfect world, each baking recipe would give adjustments for high-altitude baking. This is unfortunately not the case. Below are some basic high-altitude baking adjustments.
High-Altitude Baking Adjustments for Baking Powder, Sugar, and Liquid
The following list gives the basic adjustments for sugar, baking powder, and liquid ingredients for 3000, 5000, 7000 feet and above.
3,000 Feet
- Baking Powder: Reduce each teaspoon by 1/8 teaspoon
- Sugar: Reduce each cup by 1/2 to 1 tablespoon
- Liquid: For each cup add 1 to 2 tablespoons
5,000 Feet
- Baking Powder: Reduce each teaspoon by 1/8 to 1/4 teaspoon
- Sugar: Reduce each cup by 1/2 to 2 tablespoons
- Liquid: For each cup add 2 to 4 tablespoons
7,000 Feet
- Baking Powder: Reduce each teaspoon by 1/4 teaspoon
- Sugar: Reduce each cup by 1 to 3 tablespoons
- Liquid: For each cup add 3 to 4 tablespoons
Further Adjustments for Altitudes over 3,500 to 4,000 Feet
- Increase Oven Temperature by 25
- Increase baking time by about 5 minutes.
- Beat egg whites only to soft-peak stage.
More In-Depth Information and Recipes on High-Altitude Baking
The above adjustments are only rough guidelines.
Much can go wrong for the high-altitude baker. A cake that rises too quickly (while not being set) may rise up above the edge of the pan and flop right over into the oven. Or, it may rise very quickly and then fall. You may also get a cake that is too porous or too crumbly.
Different recipes and altitudes will require different adjustments. Ideally, the high-altitude baker should have a good set of high-altitude baking cookbooks.