MSU Extension Michigan Fresh

Food Safety and Storage

• Pick or purchase onions that are not bruised or damaged.
• Wash hands before and after handling fresh produce.
• Wash onions under cool running Do not use soap.
• Keep onions away from raw meat and meat juices to prevent cross-contamination.
• For best quality and to preserve nutrients, preserve no more than your family can consume in one year.
• Onions for fresh use can be harvested at any time during their growth.
• Bulb onions store best in cool, dry storage. For dry storage, remove the dry tops to within 1 to 3 inches from the top of the bulb. Remove any loose dirt and trim the roots. Leave the outer protective dry skin in place around the bulb. In cool, dry storage with temperatures between 35 and 55 degrees F and a relative humidity of 65–70 percent, the onions should store for 1 to 8 months.

Yield

How to Preserve

Freezing

Bulb onions store well in a cool, dry place. Michigan State University Extension does not usually recommend freezing for preserving whole onions. However, if you do freeze, see the following directions.

Whole bulb onions: Choose mature bulbs and clean as though the bulbs were going to be eaten. Blanch in boiling water whole mature bulbs for 3 minutes (small onion) to 7 minutes (large onion) or until the center is heated. Cool immediately, drain and package. Leave ½-inch headspace. Seal, label, date and freeze onions. The onions will be suitable only for cooking.

Diced onions: If chopped onions are to be frozen, they do not need to be blanched. Simply chop the onions into desired amounts, seal, label and freeze in rigid containers or plastic freezer bags. The onions will be suitable only for cooking.

Green onions: Young green onions may be chopped for salads and sandwiches and frozen without blanching, but after thawing they will not be crisp and may be slightly tough. Freezing the onions will intensify the flavor.

Onion rings: Wash, peel and slice onions. Separate the rings. Blanch in boiling water for 10 to 15 seconds. Cool immediately, drain and coat with flour. Next, dip in milk. Coat the onion rings with a mixture of equal parts cornmeal and pancake mix. Arrange as a single layer on a cookie sheet. Freeze. Then pack the rings in layers in rigid containers, using plastic wrap to separate the layers. Seal the containers, label, date and freeze. To prepare, fry frozen rings in hot oil (375 degrees F) until they are golden brown.

Note: After 3 to 6 months at 0 degrees F, onions tend to lose their flavor.

Canning

Pressure canning is the only safe method of canning onions. Onions must be pressure canned to avoid the potential of the foodborne illness botulism.

Hot Pack: Select onions of 1-inch diameter or less. Wash and peel the onions. Cover the onions with boiling water; bring to a boil. Boil the onions for 5 minutes. Pack the hot onions into clean hot jars, leaving 1-inch headspace. If desired, add ½ teaspoon of salt to pints, 1 teaspoon of salt to quarts. Remove air bubbles, wipe jar rims with clean paper towel, adjust headspace if needed, and adjust lids and process (see tables that follow for recommended processing times).

Let jars stand undisturbed for 12 to 24 hours, remove rings, check to make sure lids are sealed, wash jars, label, date and store. Food in jars that do not seal must be reprocessed in a clean jar with a new lid within 24 hours, refrigerated or frozen.

Tables were adapted from the information in Andress, E., & Harrison, J. A. (2014). So easy to preserve (Bulletin 989). (6th ed.). University of Georgia Cooperative Extension.

References

• Andress, E., & Harrison, J. A. (2014). So easy to preserve (Bulletin 989). (6th ed.). University of Georgia Cooperative Extension.
• Jauron, R. (2002). Harvesting and storing vegetables. Iowa State University Extension.
• Michigan State University Extension. (2022). How much should I buy? A guide to fresh fruits and vegetables for home cooking. https://www.canr.msu.edu/resources/how_much_ should_i_buy

More information

• Michigan Fresh
• Michigan Fresh - Vegetables