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 kilogram) per 1,000 feet (300 m).
How Altitude Affects Cooking:
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
|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.
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.
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:
[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:
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
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.
A watched pot never boils over.
Spud, that's complicated! I'm still learning to cook at 295 feet elevation!
Yes, it is complicated, but I've lived most of my life at high altitude, so I was glad to find this article, and plowed through it carefully. I made a condensed version that applies only to my present altitude. Perhaps it will improve my cooking.
I already knew that water boiled at a lower temperature (204 degrees at 4500 feet in pocatello). That means beans will never soften without using a pressure cooker.
At 295 feet, you probably don't have to do anything different than at sea level. Lucky Duck!
But you can boil water and still have the right temperature for green tea!
You live close to sea level also, don't you Plinius?
Very close. Ground floor is 3 or 4 metres below sea level and I live on the 3rd floor.