Before 1926, the aromatic Key lime was America’s common lime, so if you find yourself using an early 20th century cocktail book, your lime-infused drinks may require a bit of doctoring. Today, the limes we encounter most often are called Persian limes, a variety bred to be seedless, larger and thicker-skinned than Key limes and named for the region where the lime was first grown. Ironically, what we know to be Key limes were originally were grown in Persia, but Spanish exploration in the 15th century prompted a global biological mash-up, and plants, animals and people were suddenly inserted into new regions around the world. When Columbus introduced the lime to the Americas, the fruit was christened according to its new, tropical locale.
When researching the difference between regular Persian limes and Key limes, bartender and Small Hand Foods founder, Jennifer Colliau discovered Key limes are slightly more acidic than Persian limes, requiring an adjustment to her regular Daiquiri recipe. She also came to realize Key limes’ distinctive aroma is often perceived as sweet (in the same way aromatically “sweet” ingredients like vanilla, strawberries or bone-dry Austrian Riesling might be perceived to taste sweeter regardless of actual sugar content), meaning a balanced drink using Key lime juice actually requires less sugar.