The classic high-altitude cake has a huge sink in the middle of it — it’ll come way up, and then you pull it out and it’s concave by the time it settles. — Former high-altitude kitchen tester Betsy Bloch
The special instructions for baking at high altitude — the ones Betsy Bloch knows well — always puzzled me. For a whippersnapper living in a city resting at less than 1,000 feet above sea level, the idea of someone baking a cake at 7,000 feet was practically beyond comprehension. Those instructions always brought to mind a vision of Heidi, all grown up and baking cakes in her cozy but remote cabin amid the craggy peaks of the Alps.
Even the most confident baker can be riddled with self-doubt after relocating to Santa Fe. Recipes that were once flawless become abject failures — I was certainly forced to permanently abandon some old favorites. For better or worse, trial and error becomes the best approach — I try nearly every recipe once without adjusting and proceed from there. And as Boyd suggests, reading helps deepen your understanding. In addition to Pie in the Sky, BakeWise by biochemist Shirley Corriher applies scientific insights to baking. by Paula Figoni takes an in-depth look at ingredients and the chemical reactions that take place during baking.
In my experience, adjusting sugar, leavening, and/ or protein (whether from gluten or eggs) can help avoid high-altitude failures. At this altitude, air pressure is reduced, meaning the air is “lighter,” so cakes, cookies, and quick breads generally need smaller amounts of chemical leavenings like baking soda and powder to get the necessary spring. I rarely use a lower-protein flour than all-purpose, and the addition of an extra egg often provides the structural boost a sagging cake needs to stand up straight.
Even recipes that have succeeded before can surprise you. An almond cake that I’ve made for my sister’s birthday every year for nearly a decade recently overflowed the cupcake tins, flattened, and ultimately sank in the center. I reduced the baking soda and powder (from ¾ to ½ teaspoon of each) and the sugar (the recipe calls for a seemingly excessive 1.5 cups) by a few tablespoons. These adjustments did the trick.
One real key to consistent baking success at any altitude is the kitchen scale — and measuring ingredients by weight, not volume. A wide variety of affordable home scales are available, and even if they’re not precise to the fraction of a gram, they ensure that you measure consistently every time. To help convert recipes that don’t specify weights, King Arthur Flour offers a handy online chart (www.kingarthurflour. com/learn/ingredient-weight-chart.html).
In the case of the pumpkin sheet cake, ingredients are given in both weights and volumes, so I measured sugar and flour in cups but weighed each and compared it to the amounts the recipe specified — twice. Each time the volume weighed a good bit more than what the recipe called for. The 1.5 cups of brown sugar stood out as the real troublemaker: How do you control for the vague prescription of “firmly packed,” which I might define quite differently than you do? That difference could certainly impact the success of a cake, particularly at this altitude. In this case, the brown sugar I mashed into measuring cups came in at 354 and 367 grams, while the recipe specifies 330 grams (for the record, King Arthur’s chart equates 1.5 cups of brown sugar to approximately 320 grams).
Proceeding with the lower amount of sugar yielded a successful cake, albeit one with a very delicate, almost precipitous structure — if I hadn’t handled it carefully when inverting it onto the cooling rack, it almost certainly would’ve crumbled and broken into chunks. Alas, I wasn’t able to enjoy the cake with what sounds like lip-smackingly delicious frosting: when I retreated to my office as the cake cooled, one of my cats pranced obliviously across it, leaving a trail of sunken paw prints in its surface.
Ultimately, the keys to high-altitude success are patience and persistence. More than one of my early failed cakes got dumped with furious, frustrated force into the trash, but these days, I expect each new recipe to flop. If it doesn’t, I’m elated, and if it does, I simply scrape the flat, soggy cupcakes out of the pan and determinedly start again — from scratch.