Things You'll Need
Grapefruits belong to the citrus group of fruits along with oranges, lemons and limes. This moderately tart fruit might have originated as a cross between an orange and a pummelo – a grapefruit-shaped fruit that tastes somewhat like a less sour version of a lemon. Grapefruits tend to ripen quickly at room temperature and only stay good for about a week if you leave them out on your counter or table.
Wash your grapefruits in cool water to remove any dirt or debris from the peel. Dry the grapefruits with a towel.
Put the grapefruits into a plastic bag. Do not stuff the bag full; bruising or damaging the grapefruits will cause them to go bad faster.
Place the bag in your refrigerator. If a part of the refrigerator (such as the back wall) has a tendency to freeze, keep the bag of grapefruits away from that area.
Check the grapefruits daily. Remove and discard any that are showing signs of mold, as these will contaminate the other grapefruits and cause them to go bad more quickly. You can keep grapefruits fresh in the refrigerator for two to three weeks.