High altitude affects baking. If baking at high altitudes, follow these guidelines:
• At high altitudes, leavening agents such as baking powder, baking soda and yeast release more and larger gas bubbles, which expand very quickly and then, before the heat in the oven has firmed them, collapse, causing cakes and breads to fall. For cake batters, reduce the baking powder or soda by 1/8 tsp (0.5 mL) for each teaspoon (5 mL) called for in the recipe. Most cookie recipes need not be altered since less leavening is generally the rule.
• Since yeast doughs rise more quickly, rely more on visual cues than on suggested times to make sure the dough has risen until doubled in bulk only. If you let it rise longer, the bread may develop large air cells, causing It to fall during baking.
• Moisture evaporates at a lower temperature, which results in baked goods that are drier. Line your cake and baking pans with parchment paper or greased waxed paper.
• The internal temperature of a cake baking at high altitude Is lower, which means it will take longer than the time specified. Increase time by a few minutes, but do not alter temperature.
• Since excessive sugar weakens a cake's structure, reduce the amount of sugar called for if the initial amount is more than half the quantity of flour called for. Reduce sugar by 1 tbsp (15 mL) for every cup (250 mL) called for.