Unfortunately, no simple formula exists for converting all recipes to high altitude recipes. If you live more than 1,000 feet above sea level, it will help you to understand ways in which altitude affects cooking and to become familiar with common cooking adjustments.
At altitudes higher than 3,000 feet above sea level:
- Water boils at lower temperatures, causing moisture to evaporate more quickly. This can cause food to dry out during cooking and baking.
- Because of a lower boiling point, foods cooked in steam or boiling liquids take longer to cook.
- Lower air pressure may cause baked goods that use yeast, baking powder, baking soda, egg whites, or steam to rise excessively, then fall.
- For cakes leavened by air, such as angel food, beat the egg whites only to soft peaks; otherwise, the batter may expand too much.
- For cakes made with shortening, you may want to decrease the baking powder (start by decreasing it by 1/8 teaspoon per teaspoon called for); decrease the sugar (start by decreasing by about 1 tablespoon for each cup called for); and increase the liquid (start by increasing it one to two tablespoons for each cup called for). These estimates are based on an altitude of 3,000 feet above sea level -- at higher altitudes, you may need to alter these measures proportionately. You can also try increasing the baking temperature by 15 degrees F to 25 degrees F to help set the batter.
- When making a rich cake, reduce the shortening by one to two tablespoons per cup and add one egg (for a two-layer cake) to prevent cake from falling.
- Cookies generally yield acceptable results, but if you're not satisfied, try slightly increasing the baking temperature; slightly decreasing the baking powder or soda, fat, and/or sugar; and/or slightly increasing the liquid ingredients and flour.
- Muffinlike quick breads and biscuits generally need little adjustment, but if you find that these goods develop a bitter or alkaline flavor, decrease the baking soda or powder slightly. Because cakelike quick breads are more delicate, you may need to follow adjustment guidelines for cakes.
- Yeast breads will rise more quickly at high altitudes. Allow unshaped dough to rise only until double in size, then punch the dough down. Repeat this rising step once more before shaping dough. Flour tends to be drier at high altitudes and sometimes absorbs more liquid. If your yeast dough seems dry, add more liquid and reduce the amount of flour the next time you make the recipe.
- Large cuts of meat may take longer to cook. Be sure to use a meat thermometer to determine proper doneness.
Candy-making: Rapid evaporation caused by cooking at high altitudes can cause candies to cook down more quickly. Therefore, decrease the final cooking temperature by the difference in boiling water temperature at your altitude and that of sea level (212 degrees F). This is an approximate decrease of two degrees for every increase of 1,000 feet in elevation above sea level.
Canning and freezing foods: When canning at high altitudes, adjustments in processing time or pressure are needed to guard against contamination; when freezing, an adjustment in the blanching time is needed.
Deep-fat frying: At high altitudes, deep-fried foods can overbrown on the outside but remain underdone inside. While foods vary, a rough guideline is to lower the temperature of the fat about three degrees F for every 1,000 feet in elevation above sea level.
Cooking at altitudes higher than 6,000 feet above sea level poses further challenges because the dry air found at such elevations influences cooking. Call your local United States Department of Agriculture Extension Service Office for advice.
For more information on cooking at high altitudes, contact your county extension office or write to Colorado State University, Department of Food Science and Human Nutrition Cooperative Extension, Fort Collins, CO 80523-1571. Please use this contact only for queries regarding high-altitude cooking.