A leavening agent is just a general term for any ingredient that helps a baked good to rise, like baking soda, baking powder, or yeast. There are two types of leavening agents: chemical and biological. Baking soda and baking powder are both chemical leavening agents, because they create air pockets in batter and dough by reacting with the other ingredients. Yeast works to make breads rise by actually eating some of the heavier glucose in the dough, and then excreting gaseous carbon dioxide waste, which causes the dough to rise.
The reason is in the air that you breathe at higher elevations. The air is also drier, which means that the batter dries out and rises very quickly at higher altitudes, resulting in an irregular rise that creates large, random air pockets in the baked good, causing them to fall flat after you get them out of the oven.
Often, baked goods will rise before the ingredients have set up enough of a structure to support the rise, and the result is a flat and imploded batch of brownies. 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.
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 the amount of 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.
Baking pans: Always use the size pan your recipe calls for; 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.
Pan preparation: At high altitude, cakes tend to stick to pans, but this can be easily prevented. Up to 5, 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, 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.
Between 7, feet and 9, 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, 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. By Allrecipes Editors. Pin FB Share. Butter Cake with Berries. You may need to change the proportion of ingredients in a recipe. You may need to raise the baking temperature as well. Don't overbeat the eggs. Overbeating adds too much air to the cake. Raise the baking temperature slightly; the faster cooking time will keep the recipe from rising too much.
Also, the Colorado State University Cooperative Extension Web site has several helpful guides for baking and cooking at high altitudes. At high altitudes, about 3, feet or more above sea level, foods bake and cook differently than if prepared at sea level. Baking at High Altitudes At high altitudes: Air pressure is lower, so foods take longer to bake.
Liquids evaporate faster, so amounts of flour, sugar and liquids may need to be changed to prevent batter that is too moist, dry or gummy. Gases expand more, so doughs rise faster. Leavening agents baking soda and baking powder may need to be decreased.
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