Although there is no simple formula for converting all recipes for high-altitude conditions, follow these adjustments if you live more than 1,000 feet above sea level.
general high-altitude issues
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.
cooking above 6,000 feet
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.
suggestions for baking
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 ⅛ tsp. per tsp. called for); decrease the sugar (start by decreasing by about 1 Tbsp. for each cup called for); and increase the liquid (start by increasing it 1 to 2 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°F to 25°F to help set the batter.
When making a rich cake, reduce the shortening by 1 to 2 Tbsp. per cup and add 1 egg (for a 2-layer cake) to prevent cake from falling.
Cookies generally yield acceptable results, but if you’re not satisfied, try slightly increasing 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 flavor, decrease the baking soda or powder slightly. Because cakelike quick breads are more delicate, you may need to follow 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.
suggestions for range-top cooking
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°F). This is an approximate decrease of 2°F for every increase of 1,000 feet in elevation above sea level.
Canning & 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 (tip, Blanching).
Deep-fat frying At high altitudes, deep-fried foods can overbrown but remain underdone inside. While foods vary, a rough guideline is to lower the temperature of the fat about 3°F for every 1,000 feet in elevation above sea level.
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For more information on cooking at high altitudes, contact your county extension office or visit the Colorado State University extension services at extension.colostate.edu and search for “High Altitude Food Preparation.”