cup: lemon juice

Lemon juice is the acidic liquid extract from the fruit of Citrus limon, a small evergreen tree native to Southeast Asia and widely cultivated in Mediterranean and subtropical regions. The juice comprises approximately 5-6% citric acid by weight, which accounts for its characteristic tart flavor and pale yellow color. Fresh lemon juice is extracted by pressing or crushing ripe lemons and is distinguished from concentrated or bottled versions by its higher vitamin C content and more complex flavor profile. The fruit typically contains 40-60 milliliters of juice per lemon, with acidity levels varying by cultivar, growing conditions, and ripeness.

Lemon juice is used fresh (not fermented or processed), making it distinct from preserved lemon preparations such as preserved lemons (salt-cured whole fruits). Quality varies significantly between freshly squeezed juice and commercially bottled versions, with the latter often containing sulfites as preservatives.

Lemon juice functions as a fundamental souring agent and flavor brightener across virtually all culinary traditions. It is essential in vinaigrettes, marinades, and sauces (hollandaise, béarnaise, beurre blanc), where its acidity provides both preservation and flavor balance. In Mediterranean, Middle Eastern, and Southeast Asian cuisines, lemon juice serves as a primary acidulant, used to preserve seafood in ceviches, enhance vegetable dishes, and brighten heavy or rich preparations. It is indispensable in baking and cocktail preparation, where precise acidity levels affect both flavor and chemical reactions in doughs and batters. Lemon juice also functions as a mild natural preservative and prevents enzymatic browning in cut fruits and vegetables.