by Victoria Challancin
Growing up on an island in Lake Okeechobee in Palm Beach County, I have a visceral understanding of the term “sea level.” I knew that if I opened my front door, I could put my toe in water. I knew if I dug in the dirt, any shallow hole I made was likely to refill with water in a matter of minutes. When I baked, I knew my cakes and cookies would be perfect, or at least I knew my mother’s baking never failed.
And I learned at an early age that pound cakes were essential to life. You could eat them with fresh fruit for dessert; you could toast slices of them with an additional pound of butter for breakfast. You could feed friends and neighbors who “dropped by” back when people had time “drop by.” You made countless pound cakes and took them to any occasion where your mother had admonished you not to turn up “empty-handed.” They accompanied you to all births. To all funerals. To the homes of ailing friends. To any occasion happy or sad, a pound cake was a welcome addition and knowing how to prepare one was a requisite for growing up. So I dutifully entered the adult world armed with this culinary ammunition. And as I grew up, so did my pound cakes: over the years the basic recipe evolved. There were cream cheese versions, sour cream versions, pound cakes with black pepper, pound cakes with fresh lavender, and yes, chocolate. Of course there was chocolate.
When I moved to the Arab world, I continued with my Southern tradition. Abu Dhabi and Bahrain, countries where I lived for many years, were clearly at sea level--in fact, parts of both countries were reclaimed right from the sea. I continued making pound cakes there for my university colleagues who needed something to nibble on with their ever-present, cardamom-laced coffee. For my British friends, they were my American addition to “tea.” I made them for countless people who helped me in myriad ways. I was secure in my Southern tradition. I thought it would last forever.
And then I moved to San Miguel de Allende, Mexico. Never mind that all the books put the altitude of this charming colonial city at around 6400 feet, the GPS outside my front door clearly reads otherwise. Six thousand nine hundred feet! Do I need to tell you that this did not bode well for my beloved pound cakes? No,indeed.
My first attempt at cooking pound cake in San Miguel, after two and a half hours of cooking, yielded a beautiful cake, which had a two-inch-thick crust that when chiseled off with a putty knife tasted great, if a bit dangerous for the teeth. The inside, which remained raw, I just threw away. Clearly, something was wrong. My recipe was foolproof. It was my Mother’s, for Goodness sake! What was wrong? It clearly wasn’t the fault of my own negligence, nor genies in the oven, nor bad flour. It was the altitude. The science of cooking had finally trumped the art.
Twenty years and countless cake-making attempts later, I can say with assurance that I have learned a thing or two. Plus, there is the invaluable help and guidelines from such well-known cooks like Shirley O. Corriher, (Cookwise) and Susan Purdy (Pie in the Sky), plus venerable institutions such as the USDA.
I will now summarize this knowledge for fellow high-altitude bakers or Southerners who have strayed far from their roots.
The Science of High Altitude Baking
We all have heard that cooking is an art, baking a science. And as will all things scientific, it helps to understand what is going on. A little practical knowledge is useful when planning a remedy. A little practical knowledge makes “knowing” possible. On the other hand, don’t get bogged down in the science of it all. Don’t be too intimidated to just jump in and bake!
Some Practical Information
What constitutes a high altitude? Cakes generally behave well at 3000 feet or below. But at higher altitudes, there can be real problems. The diminished atmospheric pressure causes liquids to evaporate more quickly, causing gas bubbles to rise and pop more readily, resulting in less liquid in the cake itself. The cake may rise too quickly and the cell structure overexpand, causing the cake to have a coarse texture. With the loss of bubbles, the other ingredients, like sugar, become more concentrated and without the bubbles that actually “leven” the cake, it falls. The result is a flat, heavy, well…mess. Another unpleasant scenario is that the rapidly rising and expanding air bubbles may inflate so much that the cake actually spills over the top of the pan before deflating.
There is another feature of high-altitude living that must be factored into baking: the generally lower air pressure also means lower humidity as moisture evaporates more quickly. The rapid evaporation robs the cake of the moisture which helps to gelatinize the starch in the flour and set the cake. Those of us who live in the arid climate of the High Central Plateau of Mexico, long ago recognized that the "sucking sound" we hear, has nothing, in fact, to do with NAFTA and its effect on the American job market and everything to do with the moisture being sucked from our bodies by rather extreme climatic conditions.
The same is true for your high-altitude cakes. The gas bubbles rise quickly and coalesce, giving the cake a coarse texture; the batter overflows because it fails to “set:” cell walls rupture, causing the cake to collapse; sugars concentrate during this process, making the cake stick to the pan; the rapid loss of moisture retards the browning process, giving a pale crust. And so it goes. But just as NAFTA and dry skin have no easy answers, neither are the remedies for high altitude baking exact. The following guidelines will help, but a little experimentation will still be necessary.
Adjusting one or more key ingredients will certainly help correct problems, but don’t try to do them all at once. When baking cakes in San Miguel, I usually reduce the baking powder slightly and increase the flour, liquid, and oven temperature slightly. I don’t really do it in any measured way—just gentle unmeasured tweaks: a tad less levening, a bit more flour, a skosh more liquid. And I tend to leave the sugar alone. My oven is unreliable at best, and cooking times always vary. A bit of experimenting will help you see what works best for you, your oven, and your taste. Remember that these guidelines are for regular cakes which contain butter, sugar, and eggs, not for light sponge cakes or angel food cakes which generally have no leveners and little or no fat.
General High Altitude Adjustments
(the following guidelines have been adjusted for baking at an altitude over 6000 feet)
Baking Powder: Reduce baking powder by 1/4 teaspoon for each teaspoon listed in the recipe.
Liquid: Increase liquid by 3 to 4 tablespoons for each cup listed.
Flour: Baking in dry climates means that ingredients such as flour are also drier. Because flour is hygroscopic (i.e. it acts like a sponge), that is another reason to increase liquids in recipes using flour to compensate for the estra dryness of the flour itself.
Oven temperature: Increase baking temperature by 15 to 25 degrees Fahrenheit (this helps to set the batter before it overexpands, retards the loss of bubbles, and gives a finer texture).
Sugar: Most general guidelines for high-altitude baking suggest that for each cup of sugar given in a recipe, decrease by 2 to 3 tablespoons. I usually compensate instead, by increasing liquids and flour. If I’m going to eat cake, I figure it might as well be sweet.
Fat: Fat, such as butter or oil, weakens the cell structure of a cake, thus rich cakes which contain fat, can do with one or two tablespoons less fat per cup.
Eggs: On the other hand, the protein in eggs strengthens cell structure, thus adding an egg may prevent a cake from falling.
Cooking Time: Actual cooking time may need to be increased.
And what does all this mean for my beloved pound cakes? They still don’t look quite like they did at sea level, but with a little reduction of butter, a little prayer, a touch of vigilance…the tradition lives on.