APRIL 2007

HIGH ALTITUDE BAKING
Thin Air Doesn't Have to Cause Flat Cakes

By Porche Lovely

The idyllic Rocky Mountains have inspired poets and songwriters from Katharine Lee Bates' America the Beautiful to John Denver's Rocky Mountain High. Icicles decorate the frosted roofs of mountain lodges and parkas and hiking boots are everyday fashion. Skiers and one-horse open sleighs float through drifts of snow as white and light as the fluffiest meringue. Alas, the same altitude that draws winter sport enthusiasts sends bakers running for the hills, or more accurately, lower altitudes.

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.

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, 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.

HIGH ALTITUDE CHOCOLATE CHIP COOKIE

• see recipe

HIGH ALTITUDE BAKING GUIDELINES

• see guidelines