Baking has become a huge part of our bi-annual trips to Montana. The more we bake there, the more the pantry grows with frequently used ingredients, and desirable pieces of equipment, and the more my recipes morph to have “Montana versions;” since our home base (just outside of Big Sky) is at about 7000ft, I’ve had to manipulate a few of my favorite recipes for the altitude and it occurs to me that a few tips on how to bake successfully at high altitude could be helpful for you, dear readers, because baking at altitude is just….different. Here’s why:
As you likely have noticed, baking success depends on the specific chemical interactions of several kinds of ingredients: flour, leavening, fats, liquids. These chemical reactions are sensitive to the air in which you’re preparing them; specifically to moisture, temperature and air pressure. As you might recall from your high school chemistry classes, when heat is applied to water, it motivates the water molecules and they begin to move around. As the temperature increases, the molecules move faster eventually overcoming the bonds that are holding them together and the water comes to boil. Water boils when the pressure created by the molecules exceeds the pressure outside the water (ie: the air pressure.) The higher the altitude, the lower the air pressure, and the lower the boiling point. Since water boils faster at higher elevations, the chemical interactions in a recipe are altered because more water is evaporated before its completely baked.
So, how do you change a recipe to bake successfully at altitude? I’ve pulled together a couple of rudimentary little charts below to get you cooking. Specifically these will be helpful for making cookies, cakes, quick breads and other quick baked goods (artisan breads and yeasted doughs have another set of high-altitude rules entirely.) The specific climate, and elevation, of your kitchen will impact the recipe modifications you’ll need to make to bake something successfully (which is to say the tweak that works for your neighbor down the road, might not work exactly the same way for you.) So, embrace the fact that you might have to try your favorite recipes a couple of times to get them to your liking. I suggest that, as you start to work with a recipe, you change just one ingredient at a time to see what works for you. Take notes on what you’ve done, and try the smallest adjustment first when a range is given below.
| WHAT TO CHANGE | HOW TO CHANGE IT | WHY |
| Oven temperature | Increase 15 to 25°F; use the lower increase when making chocolate or delicate cakes. | Since leavening and evaporation proceed more quickly, the idea is to use a higher temperature to “set” the structure of baked goods before they overexpand and dry out. |
| Baking time | Decrease by 5-8 minutes per 30 minutes of baking time. | Baking at higher temperatures means products are done sooner. |
| Sugar | Decrease by 1 tablespoon per cup | Increased evaporation also increases the concentration of sugar, which can weaken the structure of what you’re baking |
| Liquid | Increase by 1 to 2 tablespoons at 3,000 feet. Increase by 1 1/2 teaspoons for each additional 1,000 feet. You can also use extra eggs as part of this liquid, depending on the recipe. | Extra liquid keeps products from drying out at higher temperatures and evaporation rates. |
| Flour | At 3,500 feet, add 1 more tablespoon per recipe. For each additional 1,500 feet, add one more tablespoon. | In some recipes, a flour with a higher protein content may yield better results. The additional flour helps to strengthen the structure of baked goods. |
Use the following chart when using baking powder and baking soda (ie: chemical leavens.) Notice that as the elevation goes up, the less leaven you’ll use (so, at 6,500ft, you’ll only use 1/4 teaspoon of leaven instead of 1 tsp.) If you’re still having trouble, and if your using a recipe that calls for both baking powder and baking soda plus an acidic ingredient (like buttermilk,) try switching to all baking powder and milk.
| 3,000-5,000 FT. | 5,000-6,500 FT | 6,500-8,000 FT | |
| BAKING POWDER OR SODA | |||
| 1 tsp | 7/8 tsp | 1/2 tsp | 1/4 tsp |
| 1 1/2 tsp | 1 1/4 tsp | 3/4 tsp | 1/2 tsp |
| 2 tsp | 1 1/2 tsp | 1 tsp | 3/4 tsp |
| 2 1/2 tsp | 1 3/4 tsp | 1 1/4 tsp | 1 tsp |
| 3 tsp | 2 tsp | 1 1/4 tsp | 1 tsp |
| 3 1/2 tsp | 2 1/2 tsp | 1 1/2 tsp | 1 tsp |
| 4 tsp | 2 1/2 tsp | 1 1/2 tsp | 1 tsp |