Let's Preserve: Sweet Corn (2024)

Recommended Varieties

Most sweet corn varieties are acceptable for canning and freezing. Bodacious and Incredible are good extra-sweet yellow varieties. Temptation, Delectable, and Providence are good extra-sweet bicolor varieties. Silver King and Whiteout are extra-sweet white varieties

Quantity

A bushel of ears weighs an average of 35 pounds and yields 6 to 11 quarts of whole-kernel style or 12 to 20 pints of cream-style corn. An average of 31½ pounds (in husks) is needed for a 7-quart canner load of whole-kernel corn. An average of 20 pounds is needed for a 9-pint canner load of cream-style corn. An average of 2½ pounds makes 1 pint of frozen whole-kernel corn.

Quality

Preserve corn within 2 to 6 hours of harvest for best quality. Select ears containing kernels of ideal maturity for eating fresh. Sweeter varieties may turn brown when canned, especially if processed at 15 pounds of pressure. Can a small amount and check color and flavor before canning large amounts. White sweet corn varieties can appear a little grayish after canning

Preparation

Start with clean countertops and utensils. Wash hands with soap and warm water. All produce should be properly washed before it is consumed or preserved. Remove the husk and silk from the ears of corn. Trim out insect-damaged kernels, if needed. Trim off ends of ears to remove small fibrous kernels. Gently rub each ear of corn under cold running water. Do not soak produce in water.

To Prepare Whole-Kernel Corn

For freezing, place ears in 1 gallon of boiling water and blanch for 3 minutes after the water returns to a boil. For canning, blanch for 3 minutes after the water returns to a boil. Cool ears and cut kernels from cob at about three-fourths of the depth of kernel. Do not scrape the cob.

To Prepare Cream-Style Corn

For freezing or canning, blanch ears for 4 minutes in boiling water. Cool ears and cut kernels from cob at about one-half of their depth. Scrape the cob with a knife to remove the remainder of the kernels and combine with half-kernels.

To Prepare Corn-on-the-Cob

For freezing, blanch small ears for 7 minutes in boiling water; blanch medium-sized ears for 9 minutes; and blanch large ears for 11 minutes. Cool in several changes of cold water and drain. If desired, cut ears into uniform 4, 6, or 8-inch (10, 15, or 20-cm) pieces.

Freezing Procedure

Don't freeze more than 2 pounds of food per cubic foot of freezer capacity per day. To package whole-kernel or cream-style corn, fill pint or quart plastic freezer containers, tapered freezer jars, or zip-type freezer bags. Squeeze air from plastic bags, seal, and label. If using rigid freezer containers, allow ½ inch (13 mm) of headspace for whole-kernel corn and 1 inch (2.5 cm) of headspace for quarts of cream-style corn. To package corn-on-the-cob, fill into quart or half-gallon freezer bags. Squeeze out air, seal, label, and freeze.

Canning Procedure

Corn must be processed in a pressure canner. Wash jars. Prepare lids according to manufacturer's instructions. Whole-kernel corn may be canned in pints or quarts. Cream-style corn must be packed in half-pint or pint jars only. If desired, add 1 teaspoon of salt per quart, ½ teaspoon per pint, or ¼ teaspoon per half-pint jar.

To Make a Raw Pack

For raw-packed whole-kernel-style corn, fill jars with cut blanched corn, leaving 1 inch (2.5 cm) of headspace. Add boiling water over the corn in each jar, leaving 1 inch (2.5 cm) of headspace. Remove air bubbles. Wipe sealing surface of jars with a clean, damp paper towel, add lids, tighten screw bands, and process.

To Make a Hot Pack

For hot-packed whole-kernel-style corn, add 1 cup of hot water for each quart of whole-kernel corn or 1 cup of hot water for each pint of cream-style corn, and heat to a boil. Fill jars with hot corn and cooking liquid, leaving 1 inch (2.5 cm) of headspace. Remove air bubbles. Wipe the sealing surface of the jars with a clean, damp paper towel, add lids, tighten screw bands, and process.

To Process in a Pressure Canner

Place jar rack, 2 (5 cm) to 3 inches (7.5 cm) of water, and sealed jars in canner. Fasten lid and heat canner on high setting. After exhausting steam for 10 minutes, add weighted gauge or close petco*ck to pressurize the canner. Start timing the recommended process when the desired pressure is reached. Regulate heat to maintain a uniform pressure. When processing is complete, remove canner from heat. Air-cool canner until it is fully depressurized. Then slowly remove weighted gauge or open petco*ck, wait 10 more minutes, and unfasten and carefully remove canner lid. Remove jars from the canner with a jar lifter, being careful not to tilt the jars, to a wooden cutting board or towel-lined surface.

Do not retighten screw bands. Cool jars for 12 to 24 hours and remove screw bands. Check lid seals. If the center of the lid is indented, the jar is sealed. Wash, dry, label, and store sealed jars in a clean, cool, dark place. If the lid is unsealed, examine and replace jar if defective, use new lid, and reprocess as before or store in the refrigerator. Wash screw bands and store separately. Canned goods are best if consumed within a year and are safe as long as lids remain vacuum sealed.

Caution

This product cannot be safely canned in a boiling water bath. Corn must be processed in a pressure canner.

Process Times

Canner gauge pressure (in pounds) at altitude of:

• 0-8,000 ft. use for dial gauge canner
• 0-Above 1,000 ft. use for weighted gauge canner

Canner gauge pressure (in pounds) at altitudes of:

• 0-8,000 ft. use for dial gauge canner
• 0-Above 1,000 ft. use for weighted gauge canner

For additional information about food preservation, visit the Penn State Extension Home Food Preservation website or contact Penn State Extension in your county.

Prepared by Martha Zepp, extension project assistant; Andy Hirneisen, senior food safety educator; and Luke LaBorde, professor of food science.