One jar of whole nutmeg could last nearly a lifetime. That means it’s a good idea to keep one whole nutmeg in your spice cabinet and store the remainder in the freezer. Some jars come with a little grater packed inside. If not, use the finest grater you have. Do not use a microplane. Whole nutmeg is extremely hard; microplanes are extremely sharp. If the nutmeg slips, you could cut your fingers badly.