Whole onions

How to select

Choose onions that are firm and dry with bright, smooth outer skins.

How to prepare

  • Rinse the onion under running water being sure to thoroughly clean the roots and stems. 
  • Dry with a paper towel. 
  • Slice the stem end. 
  • Keep the root end intact to help with cutting. 
  • Place the cut stem end on a cutting board and slice the onion in half vertically. 
  • Peel away the outer skin.

How to store

Before storage, onions should be dry, with papery skin and shriveled roots. Store whole onions in a cool, dark, well-ventilated place for use within 4 weeks. Refrigerate cut onions in a tightly sealed container for use within 2-3 days. Discard, or trim and cook, any bruised onions.

Peak season


Ways to use

  • Raw sweet and red onions are milder and can be added to salads and sandwiches.
  • Yellow and white onions are stronger and great for cooking.
  • Sauté, stir-fry, microwave, steam, boil, or braise.
  • Add to soups, sauces, casseroles, dips, and vegetable, pasta, rice, and meat dishes.

Fun facts

  • Onions, along with shallots, leeks, chives and garlic, belong to the Allium family, which has some 325 members. All have the characteristic onion smell, which is caused by volatile acids just below the skin.
  • Onions have been eaten for thousands of years. They are believed to have originally come from the Middle East and their easy cultivation suggests that their use spread quickly.
  • By the Middle Ages onions were a common vegetable throughout Europe and would have been used in soups, stews and sauces when strong flavoring was preferred.

Nutrition info and facts

Onions are full of antioxidants. Onions add flavor to many foods without adding sodium or fat. Onions are a low-calorie food and contain small amounts of iron, folate, magnesium, and other nutrients.

1 medium onion = 44 calories, 10 g carbs, 2 g fiber, 25 mg calcium, 11 mg magnesium, 32 mg phosphorus, 161 mg potassium, 8 mg vitamin C

Learn more

Growing onions in home gardens (UMN Extension)

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Foodal. How to prep fresh onions. March 20, 2022.

FoodData Central. Onions, raw. April 2018.