The apple traces its origins back thousands of years to Central Asia, spreading globally to become one of the most widely cultivated crops in temperate climates. The small selection available in a typical grocery store represents only a tiny fraction of the species’ true diversity. The number of apple “types” selected, grown, and named by humans is far greater than most people realize.
The Sheer Numbers of Apple Varieties
The total number of named apple varieties, or cultivars, developed worldwide is estimated to be over 7,500. This impressive number includes those currently grown, those preserved in genetic repositories, and those lost to history. Approximately 2,500 distinct varieties have been documented as being grown at some point in the United States.
The vast majority of these apples are not commercially viable for modern large-scale agriculture. Only about 100 apple varieties are grown for commercial purposes in the U.S. today. This difference between the thousands of known types and the few dozen commercially sold highlights the importance of preserving heirloom varieties in collections.
Defining an Apple “Type”: Cultivars vs. Species
Understanding the true diversity of apples requires distinguishing between a species and a cultivar. All common cultivated apples, from Granny Smith to Honeycrisp, belong to a single species, Malus domestica. This species is itself a hybrid, having evolved primarily from the wild species Malus sieversii in Central Asia, with contributions from other wild relatives.
The vast number of apples are therefore not different species but different cultivars. A cultivar is a plant selected by humans for specific desirable traits and maintained through asexual means, such as grafting, to ensure the new tree is a genetic clone of the parent. If an apple seed were planted, the resulting tree would almost certainly produce a new, distinct fruit because apples possess a high degree of genetic variability, known as extreme heterozygosity.
How New Varieties Emerge
The high genetic variability in apples is the primary reason why so many varieties have emerged over time. When an apple seed is planted, the resulting tree is almost always genetically unique and different from its parents, often producing fruit with undesirable traits. This means every seedling is a genetic lottery, offering a chance for a new, superior apple to emerge.
Human selection guides this natural variability, as growers intentionally cross-pollinate trees to combine desirable qualities like texture, flavor, or disease resistance. Once a unique apple with a desirable set of traits is discovered, it must be maintained by grafting a piece of the original tree onto a rootstock. New varieties can also arise from natural genetic mutations, called “sports,” which appear as a single branch on an established tree producing fruit with a slightly different color or flavor.
Categorizing Apples by Use
The thousands of existing apple cultivars are often grouped based on their intended application, which is tied to their chemical composition. The three primary categories are dessert, culinary, and cider apples. Dessert apples, intended for fresh eating, are characterized by a balanced profile of sweetness, moderate acidity, and a crisp texture, including the varieties commonly found in grocery stores.
Culinary or cooking apples are more acidic and sometimes larger, with a texture that holds its shape well when heated. The high acidity breaks down during cooking, providing a tart flavor desirable for pies and sauces. Cider apples are a specialized group whose juice is classified based on its levels of malic acid and tannins. Varietals used for cider are unpalatable for fresh eating due to high levels of astringent tannins or excessive acidity, but these qualities are necessary to create a complex, full-bodied fermented beverage.