Cheddars vary in flavor depending on the length of aging and their origin. As cheddar slowly ages, it loses moisture and its texture becomes drier and more crumbly. Sharpness becomes noticeable at 12 months (old cheddar) and 18 months (extra old cheddar). The optimal aging period is 5-6 years; however, for most uses three-year-old cheese is fine and five-year-old cheddar can be saved for special occasions.