The entire outer layer of a citrus fruit, such as a lemon, orange or grapefruit, is often called the peel or rind. These terms, however, do not tell the whole story. The very outer colored layer of the fruit is the skin. This is the part that is used for zest or in candied peels. The inner part of the peel or rind is called the pith. This part is bitter and can add an unpleasant taste if you include it in a dish by mistake. Removing the majority of a citrus fruit's peel is fairly easy, but it can be tricky not to leave some of the bitter pith behind.
Put your citrus fruit on the cutting board and cut off both ends. This will give you a flat end on which to stand the fruit and a place to start cutting off the rind.
Stand your citrus fruit upright on the cutting board.
Start cutting the peel and pith away from the fruit. Begin at the flat top of the citrus fruit. As you cut, follow the fruit's curve as closely as possible; this will allow you to preserve most of the fruit while removing most (if not all) of the skin and pith.
Cut another strip of peel off of the citrus fruit when you have completely removed the first one. Repeat this process until you have cut off all of the skin and most (if not all) of the pith from the entire fruit.
Pick up the citrus fruit gently, as it will now be very fragile. Carefully slice off any remaining pith with your sharp knife. Avoid squeezing the fruit as you do this. Without its peel to protect it, the fruit will collapse in your hand if you squeeze it.