When cooking at altitudes above 3000 feet, adjustments in the quantities of some ingredients used in a recipe may be necessary. This is especially true for cakes, pastries, and breads. The change in atmospheric pressure may require that less leavening or sugar is used or that more liquid is necessary. The baking temperature may need to be changed as well. Many prepackaged cake and bread mixes, as well as many cookbooks, offer alternate instructions for preparing a recipe at a high altitude.