Citrus juices — primarily lemon, lime, and grapefruit — are the cornerstone of cocktail acidity, providing the bright, tart backbone that balances sweetness and alcohol in sours, daiquiris, margaritas, and countless other recipes. Freshly squeezed citrus juice is considered essential in craft cocktail preparation, as its volatile aromatics and natural sugar content differ dramatically from bottled alternatives. The interplay between citrus juice and other ingredients defines the fundamental sour-sweet tension at the heart of modern mixology.