Weight Lost During Preparation

• Most varieties of storage onions lose weight even before they are cooked. Red, white and yellow onions are peeled and cored, and any bruising or imperfections are cut out. The National Onion Association says that an average-size raw onion weighs between 7 and 11 ounces before being peeled, and between 5 and 10 ounces after. About 78 percent of most onions – or 2.7 cups per pound -- end up being edible once they are peeled and cored.

Kind of Onion

• Onions that are sweeter such as Maui, Vidalia and Walla Walla, have a higher water content than more pungent storage onions. These onions are best eaten raw, without cooking, diced or sliced in sandwiches or salads. Storage onions have a higher percent of solids and take less time to cook. In a large storage onion weighing in at 5.29 ounces, 4.73 of those ounces are made up of water. Their flavor once cooked is more peppery and pungent. Green onions also have a high percentage of water. In a stalk weighing 0.42 ounces, 0.39 of those ounces are made up of water.

Cooking Method

• Before cooking, 1 cup of a chopped, yellow storage onion weighs about 5.64 ounces. When sautéed, that same cup of chopped onion weighs only 3.07 ounces. A 1/4 inch slice of onion weighs 1.3 ounces before cooking; after boiling with or without salt, that same onion slice weighs 1.13 ounces. A 2- to 3-inch-wide raw onion ring weighs 3.88 grams, raw. When breaded, fried, frozen and then baked in the oven, this same onion ring weighs 2.12 ounces. Grilling onions allows the vegetable to retain more of its water and pungent flavor, and cooks in less time than sautéing, boiling or frying. Sliced in chunks or rings, your average medium-sized onion grills up in five to 10 minutes.

Preparation Tricks and Tips

• To help reduce the tears that come from cutting raw onions, try popping the raw onion in the freezer for 10 minutes or in the refrigerator for 30 minutes prior to cutting. Rubbing your hands with lemon juice removes the onion’s smell. To get the most flavor out of your onions, cook them as close to the serving time as possible. Prepped onions that are sliced or chopped keep in refrigerated in a sealed container for up seven to 10 days, but over time, onions lose their flavor in spite of their increased smell. When cooking onions, a low to medium heat is best, because high temperatures brings out the bitterness in most onions.