Generally, one teaspoon (5 g or 1/6 oz) of baking powder is used to raise a mixture of one cup (120 g or 4oz) of flour, one cup of liquid, and one egg. However, if the mixture is acidic, baking powder's additional acids remain unconsumed in the chemical reaction and often lend an unpleasant taste to food. High acidity can be caused by ingredients such as buttermilk, lemon juice, yogurt, citrus, or honey. When excessive acid is present, some of the baking powder should be replaced with baking soda. For example, one cup of flour, one egg, and one cup of buttermilk requires only ½ teaspoon of baking powder—the remaining leavening is caused by buttermilk acids reacting with ¼ teaspoon of baking soda.