red onion

The red onion (Allium cepa var. aggregatum) is a cultivar of the common onion distinguished by its deep purple-red outer papery skin and reddish-purple inner rings. Native to Central Asia and cultivated worldwide, red onions are larger than yellow or white varieties and have a moderately sharp, slightly sweet flavor with vegetal undertones. The pigmentation comes from anthocyanin compounds, water-soluble flavonoids that intensify in color through the plant's growing season. Red onions are typically more crisp and juicy than yellow onions, making them particularly suited for raw preparations, though they soften and develop a mild sweetness when cooked or caramelized.

Red onions are valued for their distinctive color and milder flavor profile, used both raw and cooked across numerous cuisines. Raw, they appear in salads, salsas, ceviche, and pickled preparations where their crisp texture and visual appeal enhance presentation. In cooked applications, they are featured in French caramelized onion tarts, Latin American rice dishes, Indian curries, and Mediterranean vegetable medleys. Grilling or roasting mellows their sharpness further. Red onions pair well with acidic ingredients (vinegar, citrus), and their color can bleed into surrounding ingredients when raw or heavily cooked, which is sometimes desired and sometimes mitigated by salting or brief pickling.