Tart cherries, also known as sour, dwarf or Montmorency cherries, have become increasingly popular over the last couple of years. Compared to sweet cherries, which tend to be enjoyed fresh, tart cherries are often consumed dried, frozen or juiced. Cherries are a good source of fibre, vitamins and minerals, including potassium, calcium, vitamin A and folic acid. They are also well known for their antioxidant properties. A portion of 14 cherries counts as one of your five-a-day.