What is Lime Juice?

Lime juice in cocktail recipes means the expressed juice of fresh limes, strained of seeds and coarse pulp. The functional contribution is twofold: organic acids (chiefly citric) that structure a sour, and a volatile aroma that bottled product does not retain. Once squeezed, those aromatics begin to fade; ascorbic acid oxidizes, and the juice takes on dull, cooked notes within a day or two even under refrigeration.

The grocery-door bottle of preserved lime is a different ingredient: pasteurized, often from concentrate, sometimes with added sulfites or other preservatives. It will acidify a drink; it will not smell like lime.

Sharp citrus acidity, a green aromatic top note, and a little bitterness if peel oils and pith are pressed hard. Freshly squeezed juice smells of lime; bottled juice, especially from concentrate, often tastes cooked, metallic, and flat because heat treatment and ascorbic-acid degradation destroy the volatile fraction and leave oxidized notes.

Lime maps onto the tropical sour families. The Daiquiri (rum, lime, sugar), the Margarita (tequila, lime, orange liqueur), the Mojito (rum, lime, sugar, mint, soda), and the Paloma (tequila, grapefruit, lime, soda) all treat lime as the acid, not lemon. The gimlet originally used preserved lime cordial (Rose’s), a practical naval product; modern cocktail practice generally prefers fresh juice except when the cordial is historically specified.

The geographic split is old: lime where the fruit grew with sugarcane and rum or agave; lemon in the temperate whiskey and gin sours.

Cut, squeeze, and strain out seeds shortly before mixing. Three limes will typically yield a round of Daiquiris, depending on fruit size and juiciness. Do not batch juice days ahead; aroma dies in a day or two in the refrigerator.

A standard sour template with lime is about 2 oz spirit, ¾–1 oz lime, and ¾ oz simple syrup (or less if using agave syrup), adjusted to the fruit’s acidity.