Sipuli

Sipuli is the Finnish name for the common onion, the bulbous vegetable of the genus Allium. In botanical terms, the edible bulb is formed by swollen leaves and stores sugars to sustain the plant through dormancy. Onions belong to Allium cepa, an annual or biennial plant widely cultivated for culinary use. The plant typically grows best in well-drained soil with full sun and is grown from seeds, sets, or transplants, with bulb formation favored by cool to moderate temperatures and consistent moisture.

In cultivation, major onion types include storage onions (yellow or brown), red onions, and sweet onions; green onions (scallions) and shallots are related forms. Many cultivars are bred for size, color, storage life, and flavor. Harvest timing depends on climate and intended use, and cured onions store longer after harvest.

In cooking, sipuli are used worldwide in a wide range of preparations. They can be eaten raw in salads or sandwiches, sautéed as a flavor base, caramelized for sweetness, roasted, or pickled. They often provide a pungent, savory foundation to dishes and can contribute sweetness when cooked.

Nutritionally, onions are low in calories and provide vitamin C, dietary fiber, and various minerals, along with sulfur compounds and flavonoids such as quercetin. They may cause intolerance, allergies, or digestive sensitivity in some individuals and can irritate the eyes when cut.

Economically, onions are among the most widely produced vegetables. Major producers include China, India, and the United States, with cultivation spanning temperate to subtropical regions.