The lemon, Citrus × limon, is a citrustree, a hybrid of cultivated origin. The fruit are cultivated primarily for their juice, though the pulp and rind (zest) are also used, primarily in cooking or mixing. Lemon juice is about 5% citric acid, which gives lemons a sour taste; its pH is 2.3, so because of its acidity, lemon juice is commonly used in chemistry experiments.
