Which fruit is a key ingredient in a traditional key lime pie?

Key limes are the essential ingredient in a traditional key lime pie, known for their unique flavor profile that differs from regular limes. Originating from the Florida Keys, key limes are smaller, seedier, and have a more intense, aromatic flavor than their larger counterparts. This distinct tartness and fragrance contribute to the signature taste of key lime pie, making it a beloved dessert.

Regular limes, while they can be used in other recipes, do not replicate the specific taste necessary for an authentic key lime pie. Similarly, oranges and grapefruits are not suitable substitutes, as their sweetness and flavor make them incompatible with the traditional tart and creamy elements of key lime pie. Thus, key limes are essential for achieving the distinctive tartness that defines this classic dessert.