medium-size red onion

The red onion (Allium cepa var. rubrum) is a cultivar of the common onion distinguished by its deep purplish-red papery skin and reddish-purple flesh with white rings. Red onions originate from regions around the Mediterranean and Central Asia, where wild onion species were first domesticated. Medium-sized specimens typically weigh 4-6 ounces and measure 2-3 inches in diameter. The flesh is milder and slightly sweeter than yellow onions, with a more delicate texture and less pungent sulfur compounds. The red pigmentation comes from anthocyanin antioxidants. Key varieties include Walla Walla, Red Wing, and Indian Red.

Red onions are prized for raw preparations where their mild sweetness and vibrant color are showcased, including slaws, salads, salsas, and pickled preparations. They are also grilled, caramelized, roasted, or used in soups and stews. In Mediterranean, Indian, and Latin American cuisines, red onions feature prominently in fresh salsas, ceviche, and curries. The anthocyanins are sensitive to heat and acidity, turning the onion blue or gray when cooked with alkaline substances; this property is exploited in some pickling traditions. Red onions pair well with vinegar, citrus, and acidic elements that preserve their color.