lemon juice - about ½ a small lemon

Lemon juice is the acidic liquid extracted from the Citrus limon fruit, a small, yellow citrus native to Southeast Asia and now cultivated widely in Mediterranean regions. The juice comprises approximately 5-6% citric acid by weight, along with ascorbic acid (vitamin C), water, and trace minerals. Fresh-squeezed lemon juice has a bright, sharp acidity with subtle floral and slightly bitter undertones, distinguishing it from concentrated or bottled varieties, which may lack the same aromatic complexity and contain preservatives.

Key cultivars include Eureka and Lisbon lemons, which are the most common commercial varieties, as well as specialty types like Meyer lemons (sweeter, less acidic) and Ponderosa lemons (very large, juicy). The juice's potency varies with ripeness, growing conditions, and harvest season, with peak acidity and flavor occurring when lemons are fully yellow.

Lemon juice functions as both a flavoring agent and a functional ingredient across global cuisines. It brightens dishes by adding acidity and complexity—essential in vinaigrettes, marinades, sauces, and dressings. In Mediterranean cooking, lemon juice is fundamental to Greek, Italian, and Spanish cuisines, while Middle Eastern and North African cuisines employ it in preserved lemon preparations and tart-savory dishes. Beyond flavor, lemon juice prevents enzymatic browning in produce, aids emulsification in mayonnaise and hollandaise, and tenderizes proteins through its acid content. It is used in baking to activate baking soda, in beverages (fresh juice, cocktails, tea), and as a preservative in pickling and canning applications.