Lime

Two main commercial limes

The “lime” sold in supermarkets is mostly one of two species:

• Persian / Tahiti lime (Citrus latifolia) — larger (5–7 cm), seedless, mildly acidic. Most U.S. commercial lime is this.
• Key / Mexican lime (Citrus aurantiifolia) — smaller (2–4 cm), seedy, more intensely flavored, more aromatic. The lime of Key lime pie.

The two are different species, with the Key lime closer to the original Asian limes that traveled westward.

Why “limey”

British sailors were called “limeys” because the British Royal Navy required citrus rations to prevent scurvy (vitamin C deficiency) starting in 1747. Initially they used Mediterranean lemons, but switched to West Indian limes around 1860 — which had less vitamin C, contributing to the disease’s resurgence in long voyages.

The nickname stuck regardless. American sailors and civilians began using “limey” as a slang term for British sailors, then later for the British generally.

Cooking with citrus

Lime juice is acidic enough to chemically denature proteins — the basis of:

• Ceviche (Latin American) — raw fish “cooked” by lime juice for hours.
• Tom yum (Thai) — sour shrimp soup.
• Mexican cuisine — lime juice in salsa, marinades, micheladas.
• Margaritas — Mexican cocktail with tequila, lime, triple sec.

The citric and ascorbic acids in lime juice produce a stronger denaturation than vinegar, partly explaining lime’s preferred status in many Asian and Latin American cuisines.

Key lime pie

Florida’s Key lime pie is a regional specialty with a fixed canonical formula:

• Sweetened condensed milk (its presence reflects Florida’s pre-refrigeration era)
• Key lime juice (or substitute)
• Egg yolks
• Graham cracker crust
• Optional whipped cream or meringue topping

Real Key limes are nearly extinct from commercial Florida agriculture due to disease; modern Key lime pies often use bottled juice from Mexico-grown Key limes.