Grapefruit is a citrus fruit. Once peeled, the inside of a grapefruit is very similar to the inside of an orange; a pulpy, juicy fruit that formed into segments. It can be used in much the same way as an orange or mandarin, remembering that it is quite acidic and it’s best to remove the membrane as well as the pith before eating, as both are bitter. If eating the grapefruit without removing the membrane (such as when scooping flesh out after cutting off the top of the grapefruit), sprinkle a little sugar on the flesh to counteract the sharp flavor.