High Altitude Baking
Recipes, tips, and the science behind baking great pies, cakes, and cookies above sea level
Are you struggling to make the perfect pastry? Or do your cookies crumble and your cakes collapse? It may not be your fault. If you live and bake 2,500 feet (762 meters) or more above sea level, you get to blame everything on the altitude! Often more frustration than fun, baking at high altitude can be a challenge or a total disaster, but at least you are not alone. Professional and home bakers struggle with this in as many as 34 of the 50 United States, parts of Canada, Mexico, South America, and Europe, plus other mountainous regions around the globe. If you have never heard of these problems, you probably live at or near sea level, though you might have wondered why mountain dwellers around the world make flatbreads (Mexican tortillas, for example). But ask anyone who has moved from Boston to Boulder how their cakes turn out and, if they are honest, they'll tell you the name of the best bakery in town.
Read further for the science behind this as well as for a variety of tips and ideas to assist you.
The Science behind High Altitude Baking:
Wherever you cook or bake, results depend on many factors including food chemistry, atmospheric pressure, climate, and elevation. The higher you climb, the thinner the air and therefore, the lower the atmospheric pressure. Beginning 2,500 to 3,000 feet above sea level, altitude starts to affect all cooking, but especially baking, in three significant ways:
1. The higher the elevation, the lower the boiling point of water (212°F at sea level, 206.7°F at 3,000 feet, 203.2°Fat 5,000 feet, 199°F at 7,000 feet, 194.7°F at 10,000 feet). When water boils at lower temperatures:
* It takes longer for foods to cook in or over water.
* Dense moist batter and dough take longer to completely bake in the center.
2. The higher the elevation, the faster moisture evaporates. When moisture evaporates quickly:
* The ratio of liquid to solid changes, potentially weakening the overall structure of whatever you're baking.
* Flavors tend to be less pronounced because there are fewer moisture molecules to carry aroma to the nose.
* Baked goods dry out and go stale at an accelerated rate.
3. The higher the elevation, the faster leavening gases (air, carbon dioxide, and water vapor) expand. When leavening gases expand quickly:
* Cakes may rise too far too fast?and will sink in the center or collapse when cooling.
* Stiffly beaten egg whites expand quickly until they literally pop during baking, causing a cake to collapse as it cools.
* Yeast breads can easily over-proof (rise too much).
Baking Basics:
Almost all recipes are developed for use at sea level and, when used at or above 2,500 to 3,000 feet in elevation they will require adjustments for optimal results. Baking above sea level can be tricky because one set of adjustments emphatically does not fit all situations; each recipe, altitude, and set of atmospheric conditions is unique. However, different kinds of baked goods do tend to follow certain patterns. Below, are general guidelines for baking cakes, pies, cookies, muffins, quick breads, and yeast breads at high altitude.
Cakes
The delicate formulas that make cakes rise and maintain texture are strongly affected by changes in elevation. Some rising problems crop up between 2,500 and 3,000 feet; above 5,000 feet, cakes typically rise during baking, but may fall or cave in; or they may have a heavy, coarse crumb. Batter may be strengthened by reducing sugar, or adding eggs, egg yolks, or slightly more flour. Acidity helps batter set quickly in the oven's heat, so replacing regular milk with buttermilk, sour cream, or yogurt can be helpful. Leavening is usually reduced, while flavoring agents are increased. Oven heat is sometimes increased 25°F or the temperature is kept moderate (350°F) but baking times increased. Boxed cake mixes often include high-altitude adjustments, but beware?they are designed to work up to about 6,000 feet only; above that, cakes crash. Fortunately, many boxed cake mixes can be fixed using the same methods as you would for cakes made from scratch.
Pies
One of the myths of high-altitude baking is that pies need no adjustment. That is not exactly true, though pies are easier to adjust than cakes. Pie crusts are often too dry and need slightly more liquid to become pliable (be careful: too much liquid can develop gluten and toughen crusts). Baking pie fillings all the way through takes longer than it would at sea level. Cover pies loosely with foil during part of the baking time to prevent the top crust from burning before the fruit beneath is completely cooked.
Cookies
Cookie recipes often work without changes up to about 7,000 feet, but they sometimes spread too much or get tough. Some cookie recipes require less sugar, leavening, or fat; others only need a little more liquid and flour (avoid too much flour, it can make them tough), and some need only a slight increase in oven heat (15°F to 25°F).
Muffins & Quick Breads
This category also includes scones, biscuits, and cornbread. For the correct rise at high altitude, baking powder or baking soda must be reduced slightly. Also, you get a better rise and quicker set with an acidic batter, so you can reduce some of the baking soda, which neutralizes acidity?don't omit all of it as some is needed for leavening. To strengthen batter and prevent collapse, sugar is reduced and flour increased. Extra liquid can be added (it is especially good to substitute buttermilk or yogurt for water or milk) to compensate for dry air and drier flour at altitude. Quick breads baked in loaf pans may crust over and start to brown on top before the batter underneath begins to set. To prevent this, sometimes it is helpful to cover the pan loosely with foil after half the baking time or to substitute a tube pan for a loaf pan. To get a better rise between 4,000 and 6,000 feet, increase oven temperature by 15°F to 25°F. At higher elevations, keep original heat and increase baking time slightly.
Yeast Breads
At high altitude, bread tends to rise much more rapidly than at sea level and changes in ingredients or technique are needed to slow down this action. Some bakers reduce their yeast slightly or use ice water instead of warm water, while others punch down their dough more often, then add extra rises or one overnight rise in the refrigerator. Beware of dough that has risen too much or "over-proofed" before baking; it may warp, droop, or collapse in the oven. To prevent over-proofing at high altitude, only allow dough to rise about a third?not double in bulk?before baking. Never omit salt: At high altitudes, salt is essential not only for flavor, but also to slow down the growth of yeast and the expansion of gases. To achieve good rise and a crisp crust at high altitude, begin baking bread with a pan of boiling water on the bottom of the oven, then remove the water for the final 15 minutes of baking.
Ingredients:
The previous section discusses the way several categories of baked goods react above sea level and what to do to eliminate problems. Below is an outline of what to expect from various ingredients at altitude and how to make adjustments for successful baking. Remember that every recipe is different and will often require several tries to get it just right for your elevation.
Liquids
Because liquid evaporates more quickly at altitude and mountain air can dry out flour, adding more liquid (two to four tablespoons, depending on the elevation) to a recipe is often very helpful.
Flour
Increasing the amount of flour (one to four tablespoons, depending on the elevation) in recipes can improve the structural strength of a batter. However, flour's protein content is the most important factor governing liquid-to-flour ratios: Bread flour absorbs more liquid than all-purpose flour, which in turn absorbs more than cake or pastry flour. At high altitude, all-purpose flour is preferred over cake or pastry flour because it is stronger, has more protein, and helps baked goods maintain their shape as they cool.
Leavening
Because of the rapid expansion of leavening gases, you usually need to decrease the amount of baking powder or baking soda as elevation increases (decrease each teaspoon of leavening by 1/8 to 2/3 teaspoon, depending on altitude). Whipped whole eggs are sometimes used as leavening; they should be slightly under-whipped at high altitude. Whipped egg whites are often used as leavening. A sea-level recipe may call for whites whipped to stiff peaks (air cells are fully expanded), but above 3,000 feet elevation egg whites must be whipped only until they form soft peaks, leaving room in the air cells so they can expand while baking and remain stable when cool.
Eggs
Eggs add liquid as well as fat and protein to baked goods. Occasionally you can adjust a sea-level cake recipe for altitude simply by adding one more large egg. The egg white contributes strength and the yolk contains a natural emulsifier that allows batter to hold extra sugar without weakening the overall structure. Yolks also contribute richness and tenderness, which can counteract the drying effects of baking at altitude.
Fats
Fat weakens the gluten in flour and thereby creates tender baked products; this is good at sea level, but at high altitude, when fats are concentrated because of moisture loss, excess fat can weaken cell structure too much. In very rich cakes and some cookies, you need to decrease fat by a tablespoon or two to maintain structural strength.
Sugar
Sugar also weakens the gluten in flour. Excess sugar (or other sweetener) can weaken a cake's structure and hasten its collapse. The fix: In many recipes, reduce the amount of sugar by one to four tablespoons as altitude increases.
Acidity
Acidic batters tend to set more quickly than others. In addition, acidic ingredients hold moisture in batter when reacting with baking soda. Therefore, at high altitude, most recipes for baked goods are improved by substituting buttermilk, sour milk, yogurt, or sour cream (all high in acidity) for regular (whole or low-fat) milk (which is lower in acidity).
More Tips:
Adjustments to oven temperature, baking time, pan selection, and pan preparation can significantly affect the outcome of high-altitude baking. Here are tips for manipulating these factors at high altitude, plus notes on storage.
Baking pans/Pan preparation
Always use pan sizes specified in your recipe; since baked goods rise markedly at high altitude, they may over-rise and spill into the oven if baked in a pan that's too small. Substituting a tube pan for a loaf or round pan will bring heat to the batter's center, usually resulting in a better rise and quicker set, especially for dense, fruited cakes. You can make your own tube pan by taking a round cake pan and placing a metal "cake tube"?sold for this purpose at bakeware shops?or an overturned one-cup metal measuring cup (without handle) in the center.
At high altitude, cakes tend to stick to pans, but this can be easily prevented. Up to 5,000 feet, it's sufficient to grease and flour pans, but if you're above that altitude, grease pan, line with parchment or wax paper, then grease and flour the paper. When baking cookies, it's best to use single-layer cookie sheets; insulated, double-layer pans reduce surface heat and prevent crisping. Prepare muffin pans by coating with shortening or nonstick vegetable spray. At 9,000 feet and above, muffins tend to stick even more so grease and flour pans or line them with paper or foil muffin cups.
Baking temperatures and times
At high altitude it's critical to completely preheat your oven?give it at least 15 minutes?because you need to get all the heat you can from it. Use an auxiliary thermometer inside the oven to make sure the temperature is correct. Oven rack placement is equally important: The hottest position is at the bottom (closest to the heat source); the middle rack delivers moderate, even heat.
From 5,000 feet to 7,000 feet, baking is often improved by raising the oven temperature 15°F to 25°F because the extra heat quickly sets the batter's cell structure. Between 7,000 feet and 9,000 feet, raising the temperature can sometimes cause over-crusting on the surface of baked goods. Instead, it's best to use a moderate heat and increase the baking time. At 9,000 feet and above, preheat oven about 25 degrees above the baking temperature called for in the recipe. As soon as the baked goods are placed inside the oven, lower the heat to the actual baking temperature called for in the recipe.
Storing Baked Goods
At high altitude, baked goods dry out and get stale quickly. As soon as they are completely cool, wrap them in airtight plastic wrap or sealable plastic bags. For long storage, double-wrap in airtight plastic, then cover with heavy-duty foil or place in heavy-duty freezer bags.
