The tree's ellipsoidal yellow fruit is used for culinary and non-culinary purposes throughout the world, primarily for its juice, though the pulp and rind (zest) are also used in cooking and baking. The juice of the lemon is about 5% to 6% citric acid, which gives lemons a sour taste. Fun Fact: Know how they say to roll a lemon on a counter top to break the cells inside that hold the liquid in order to get more juice out of juicing them? Well, you can microwave them for 20 seconds as well, just to get every bit possible! You should be able to get 2-3 tablespoons of juice per lemon.