High Altitude and Its Effect on Cooking

Most recipes and temperature guidelines are calibrated for sea-level conditions, but what if you live in a high-altitude area like we do here in Utah? The lower atmospheric pressure at high altitudes (generally 3,000 ft [900 meters] or higher is considered high altitude) can wreak havoc on your culinary performance. Knowing a few simple adjustments will be a game-changer.

Boiling Point Depends on Elevation:

The boiling point of any liquid depends on the atmospheric pressure bearing down on its surface: the higher the pressure, the more energy it takes for liquid molecules to escape the surface and become a gas, and so the higher the temperature at which the liquid boils. —Harold McGee, On Food and Cooking, pg. 785

Under (less) Pressure: Because of gravity, the higher you go, the fewer air molecules there are in a given space, so the air is less dense. Because of the lower air pressure, water molecules in a pot need less energy to escape into the air. At altitudes over 3,000 ft (900 m), the decreased air pressure may require you to alter the time, temperature, or a few ingredients in your recipe. At sea level, the atmospheric pressure is 14.7 pounds (7 kilograms) per square inch (psi); and this decreases by about 1/2 pound (1/4 kilogram) per 1,000 feet (300 m).

How Altitude Affects Cooking:

1. Water and other liquids evaporate faster and boil at lower temperatures.
2. Leavening gasses in breads and cakes expand more quickly.

Boiling Point: The temperature at which water boils decreases as elevation increases. Because foods that are boiled are cooking at lower temperatures, they may require a longer cooking time. This affects foods like cooking dry beans, vegetables, pot roasts, soups, and stews. At high enough altitudes, high starch foods like pasta and beans may never cook properly.

Approximate Boiling Temperatures of Water at Various Altitudes
Altitude	Temperature
Sea Level	212°F (100°C)
2,000 ft. (600 m)	208°F (98°C)
5,000 ft. (1,500 m)	203°F (95°C)
7,500 ft. (2,300 m)	198°F (92°C)
10,000 ft. (3,000 m)	193°F (90°C)

A Watched Pot Never Boils.

Definitely true. Avert your eyes. —The Food Lab, Kenji Lopez-Alt, pg. 99

Pressure Cookers: Pressure cookers can be a lifesaver when cooking at high altitude. Their seals are vapor tight. As the water begins to boil, the steam that takes up more space than water cannot escape and increases the pressure in the pot. You’ll be able to reach much higher temperatures than you could in the open air environment.

Moisture Loss: High altitude areas often have low humidity, which will cause water to evaporate even more quickly. Food should be covered or wrapped to avoid excessive moisture loss.

Deep-Fat Frying: The lower boiling point of water in foods requires lowering the temperature of the fat to prevent food from over browning on the outside while being undercooked on the inside. Decrease the frying temperature about 3°F (1°C) for every 1,000 ft (300 meters) increase in elevation.

Microwave Cooking: Because water evaporates more quickly at higher altitude, microwave cooking times may need to be adjusted.

• A lower boiling point may mean a longer cooking time for your food
• Since foods will leaven, or puff more with less air pressure, be sure to use containers for your food that will accommodate the increase in volume.

Thermal Tip:

Temperature adjustments are to be applied to target temperatures stated in recipes. Your thermometer’s accuracy is not compromised at high altitude and does not need to be calibrated to accommodate the conditions caused by decreased air pressure.

Candy Making: Use your Thermapen^® to test the boiling point of water at your altitude. Reduce the target sugar cooking temperature by the difference between your boiling point and 212°F (100°C) to avoid sugar cooked beyond your targeted stage. This will be approximately a decrease of 2°F (1°C) for every increase of 1,000 feet (300 meters) in elevation above sea level.

Yeast Breads: With the decreased air pressure, yeast doughs will rise in a shorter period of time. The dough’s flavor is developed over time, and the shortened time compromises that quality. You can decrease the amount of yeast to lengthen the fermentation time. Additional water may need to be added so the lack of humidity combined with the quick water evaporation does not dry out the loaf.

Bread Machines:

• Decrease yeast by 1/4–1/2 tsp. for every package called for in the recipe.
• Add up to 1–2 T. of additional liquid per cup of flour in the recipe.
• Use a longer mixing cycle to allow the gluten to develop more fully. A stronger dough will withstand a more intense rise better.

Cookies: Cookies can often spread too much during baking at high altitudes; this is from high levels of sugar and fat in the cookie dough. Results can be improved by:

• Slight increase in baking temperature.
• A Slight decrease in chemical leaveners (baking powder and baking soda), sugar, and/or fat. These ingredients can cause excess spreading.
• Slight increase in liquid ingredients and flour. This will toughen the dough and help it to resist spreading.

Falling Cakes:

[A cake’s] structure is compromised further by decreased air pressure: The cakes rise too much, the structure can’t support the rise, and the cakes collapse. —Heavenly Cakes, Rose Levy Beranbaum, pg. 434

Cakes and Quick Breads: At high altitude cakes and quick breads can have excessive rising because of low atmospheric pressure. The cell structure stretches, making the resulting texture coarse, or the stretching can be so excessive that the cake will lose its structure and fall. Simple adjustments can be made to ensure your success:

• Measure accurately and reduce chemical leaveners (see table below).
• Increase baking temperature by 15–25°F (6–10°C) to help “set” the batter before cells formed during rising expand too much.
• Increased water evaporation will increase the concentration of sugar, which weakens the cell structure (because sugar weakens gluten strength). Decrease sugar and increase liquid slightly.
• Rich butter cakes can benefit from a reduction in their fat content. Fats weaken gluten strength just like sugars do. Increasing the amount of egg will strengthen the cell structure and may prevent a cake from falling.
• When making foam cakes, whip egg whites less. Soft peaks instead of stiff will allow for greater expansion during baking.

Cake Mixes: The addition of flour and liquid can help strengthen the cake batter against excessive rising, and subsequent falling. High altitude adjustments are usually provided on cake mix boxes.

Cake Recipe Adjustments for High Altitude
Adjustment	3,500 to 6,500 ft. (1,000-2,000 m)	6,500 to 8,500 ft. (2,000-2,600 m)	8,500 to 10,000 ft. (2,600-3,000 m)
Reduce baking powder, for each tsp., decrease:	1/8 tsp.	1/8-1/4 tsp.	1/4 tsp.
Reduce sugar, for each cup, decrease:	0-1 Tbsp.	0-2 Tbsp.	1-3 Tbsp.
Increase liquid, for each cup, add:	1-2 Tbsp.	2-4 Tbsp.	3-4 Tbsp.

These tips and adjustments will be helpful in making your high-altitude cooking more successful. Trial and error will be involved as you adjust your recipes and methods. Try only one adjustment at a time so you can more easily isolate the changes occurring, and take notes through the entire process so you can repeat the change in the future. Over time, adjusting recipes to your specific conditions will become less daunting, and more second-nature.

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Products Featured:

Resources:

High Altitude Food Preparation, from Colorado State University Extension

The Food Lab, Kenji Lopez-Alt

On Food and Cooking, Harold McGee

Heavenly Cakes, Rose Levy Beranbaum