For years, the effects of high altitude have been recognized by the sporting world. According to The New York Times, ninety-five percent of Olympic medalists live or train at high altitude. Manufacturers produce specialized tennis balls to compensate for the difference in air pressure. The Colorado Rockies, Denver’s Major League Baseball team, for several years led the league in home runs because the city’s thin air allowed balls to travel extra distance. (The team installed a humidor in 2002 to help combat the home run spree.)
The same conditions—low air density, low air pressure, and low humidity—that are a boon to athletes are the bane of pastry chefs and home bakers alike far beyond the Rocky Mountains. According to the USDA, from sea to shining sea, one-third of the U.S. population lives at elevations above 3,000 feet. In other words, 100 million Americans deal with the challenges of high altitude baking on a daily basis.
To understand why baking at altitude is different than baking at sea level, it’s important to look at how these atmospheric conditions affect the baking process. The weight of air, measured in pounds per square inch (psi), decreases by nearly one-third between sea level and an elevation of 10,000 feet. The decrease in atmospheric pressure lowers the boiling point of water which means that during baking more water is evaporated before the cake tester shows that the cake is done. With the amount of water in the recipe reduced, the rest of the ratios are thrown out of wack. Less water means a higher concentration of sugar. Since sugar tenderizes and keeps baked goods moist, too much sugar can make a cake end up looking more like a big gloppy mess than a delicate tempting treat. Reducing the sugar in a recipe will help. But to keep sweets sweet and retain the moistness that is so precious at drier high altitudes, the sugar can’t be cut too much. It’s crucial to shore up structure with additional flour and eggs and to increase the liquid ingredients to compensate for the excess loss of moisture.
Another key component of successful high altitude baking is to decrease the amount of baking powder and baking soda. In a sea level formula air and carbon dioxide are equally matched opponents. Air, which is heavier than at high altitudes due to higher atmospheric pressure and moisture, pushes against the carbon dioxide gas produced by the leavening agent as it expands in the heat of the oven. As this same formula is taken to higher and higher elevations, the air pressure puts up less and less of a fight against the leavening. Like a balloon that’s been blown up and had the air let out, a favorite cake or quick bread will rise gloriously in the oven but then shrink to a shadow of its former self as it cools. The lower boiling temperature of water also affects taste; less of the baking soda or baking powder is neutralized during baking which can leave a bitter, soapy, or metallic aftertaste.
Making changes to the method of preparation can also be an advantage to high altitude bakers. The sea level practice of creaming butter and sugar together “until light and fluffy” and beating egg whites until stiff can be troublesome, especially for cakes. Above 3,000 feet, both mixing practices incorporate too much air, which, like excess leavening gases, can overly expand in the oven, weakening the structure and resulting in a coarse texture. Instead, cream the butter and sugar just until well combined and beat egg whites only to soft peaks. Many recipes can also benefit from increasing the oven temperature by 25°F to set the batter’s structure before an over expansion of leavening gases can occur.
Expert food scientists and experienced high altitude bakers agree that adjusting recipes for high altitude is as much of an art as it is a science. Kim Boos, chef/owner of Haute Cakes in Boulder, Colorado, believes that experimentation is key. When it comes to testing her own recipes, the lifelong altitude baker knows that “trial and error definitely goes into it.” She doesn’t feel that she’s mastered a recipe until she’s tried it ten times, sees it go through different changes, and ultimately reaches her ideal version. Mary Schroeder, MS, RD, with Colorado State University’s Food Science and Nutrition department, agrees. According to Mary, “It often requires a little experimenting to see what combination of adjustments works best for a particular recipe. Even if you have the science part figured out, there is still the art of fine-tuning to consider in order to get your desired finished product.”
Kim has perfected a chocolate cake recipe that is both super moist yet sturdy enough for wedding cakes that she keeps a secret. She is, however, willing to share her chocolate chip cookie recipe. By adjusting the baking soda, playing with the ratio of white to brown sugar, and adding egg yolks in addition to whole eggs, Kim bakes a chocolate chip cookie that is crunchy on the outside and gooey on the inside. At an altitude where cookies tend to spread too much and end up tough, Kim’s cookies stand tall and stay moist.
CHOCOLATE CHIP COOKIE
Pastry Chef Kim Boos, Haute Cakes
4 1/2 cups all-purpose flour
1 teaspoon salt
1 teaspoon baking soda
1 1/2 cup unsalted butter, at room temperature
2 cups light brown sugar
1 cup sugar
3 large eggs
1 large egg yolk
2 teaspoons vanilla extract
2 cups chocolate chips, preferably cacao 55% or above
In a mixing bowl, combine dry ingredients. In the bowl of a stand mixer fitted with a paddle attachment, cream butter and sugar until pale and fluffy. Beat in eggs and vanilla. Add dry ingredients and mix until just combined. Add chocolate chips. Scoop dough and freeze or chill overnight. Bake at 350°F until lightly golden, about 12 minutes.
* In general, decrease the chemical leavening agents, starting first with baking powder, and then the baking soda. Also decrease the sugar.
* Increase the flour, eggs, and liquids.
* Fats may need to be reduced. Try this last, especially if your recipe’s structure is a problem at the higher altitudes.
|ADJUSTMENTS BY WEIGHT*|
|ingredient||adjustment||at 5,000 feet||at 7,500 feet|
|fats (only if needed)||decrease by||no change||10%|
*Information provided by Johnson & Wales University
|ADJUSTMENTS BY MEASURE**|
|eggs||increase by||1 egg|
|fats (only if needed)||decrease by||1 to 2 tablespoons|
|flour||increase by||1 to 3 tablespoons per cup|
|leavening||decrease by||1/8 to 1/4 teaspoon per teaspoon|
|liquids||increase by||1 to 4 tablespoons per cup|
|sugar||decrease by||1 to 3 tablespoons per cup|
Start with smaller adjustments first, and then move to larger ones as you refine the recipes. Lower altitudes will require smaller adjustments.
**Information provided by Colorado State University, Department of Food Science & Human Nutrition
MORE HELPFUL HINTS
* Curds and cream fillings may require additional cooking time and the use of direct heat in order to thicken properly.
* For items cooked to a specific temperature on the stove, use a candy thermometer for accuracy. Lower the temperature called for in the recipe by approximately 2°F per 1,000 feet of elevation. To determine an exact final temperature, take the temperature of boiling water and subtract that number from 212°F. (boiling temperature at sea level).
* Watch yeast breads carefully. Pay attention to the size of the dough, not the amount of time that it has been rising. Dough will double in size faster at high altitudes. Add an additional rise for improved flavor development.