A sour cherry, sometimes referred to as pie or tart cherry, is a small, fruit-producing tree native to Europe and Asia. The small, dark red to black colored cherries produced by the tree are acidic and used primarily for cooking. Sour cherry grows to a height of approximately 13-30 feet (4-10 meters) in height, and has twiggy branches with the cherries developing on shorter stalks.
Sour cherries were cultivated as early as 300 BCE by the ancient Greeks. They were also popular amongst Persians and Romans, who introduced the fruits to Britain before the 1st century CE. The sour cherry remains popular today around the world, but particularly in Iran.
The cultivation of sour cherries was popularized in Britain in the early 16th century. By the 1640s, more than twenty different sour cherry cultivars were named. By the time of the Second World War, more than fifty different cultivars were known in England. In modern times, very few of these are grown for commercial purposes.
Sour cherry trees require rich, well-drained, moist soil to thrive. It also has a higher water and nitrogen requirement than its cousin, the sweet cherry tree. Although most varieties of sour cherry are too large for the backyard garden, smaller dwarf varieties have recently become available. These garden-friendly varieties require regular maintenance, including protecting flowers, mulching, weeding, and fertilizing in the spring.
Many gardeners prefer the sour cherry because it is not prone to pests and diseases like the sweet cherry. It is more susceptible to fruit loss from birds, and the fruit must be protected with netting during the summer months. Harvesting of the ripened fruit consists of cutting the cherries from the tree rather than pulling them from the stalk. The cherries are delicate and this practice reduces the risk of damage.
Eating sour cherries fresh is a common practice in the Middle East. However, in other parts of Europe, as well as the United States and Canada, the cherries are too sour for most palates. They are most frequently used in cooking soups and dishes made with pork. When cooked with sugar, their natural acidity is balanced, and the flavor and aroma are brought to the forefront. Many different liqueurs, preserves, drinks, and deserts are made with sour cherries, or sour cherry syrup.
Sour cherries contain fewer calories than the sweet varieties, due to their lower sugar content. They are rich in vitamin C, carbohydrates, and water. Sour cherries also include trace amounts of fiber, protein, vitamin A, niacin, calcium, riboflavin, phosphorus, potassium, iron, and vitamins B1 and B2.