AUBURN UNIVERSITY, Ala. – Fresh from the garden vegetables make any meal better. While many fresh garden vegetables are available this time of year, there is a way to have the same fresh selections all year long. With a few simple steps, people can freeze and store almost every garden vegetable. Having high-quality frozen vegetables that keep their taste and nutrients relies heavily on the selection, preparation and storing processes.
Bridgette Brannon, an Alabama Extension food safety and quality regional agent, said the best vegetables to freeze are ones that are picked at peak freshness.
“Picking vegetables that have just reached peak freshness and are tender are suitable for freezing,” Brannon said. “The fresher the vegetable and the shorter the amount of time between harvesting and freezing will provide for a premium product.”
Also, for the best results, pick vegetables early in the morning when the dew is just off the vines.
One of the most important steps to preparing garden vegetables for freezing is to thoroughly wash them. In order to do this, move the vegetables up and down when washing to agitate the water and remove trash and dirt. While washing, make sure to remove any inferior vegetables and begin to sort them for size.
Brannon said with the exception of bell peppers, blanching vegetables is an essential step to preparing vegetables for freezing that must not be skipped.
“Blanching occurs when you cook the vegetables for a short period of time in boiling water, then move the vegetables to ice water to stop the cooking,” Brannon said.
This process stops the enzyme action that eradicates the fresh taste of the vegetables. If blanching does not occur, the enzymes are still in their active state. This will cause a color and flavor change in the vegetables after approximately four to six weeks in the freezer.
Steps to Blanching
When blanching, use only approximately 1 pound of vegetables in 1 gallon of boiling water to provide the highest quality product. To destroy the enzymes, the boiling water must be able to circulate around each piece of vegetable.
“Vegetables must reach an internal temperature of 180 to 190 degrees F to destroy the enzymes,” she said. “It is important to keep the burner on high and place the lid on the blancher as soon as the vegetables are submerged in the boiling water. Make sure to remove the lid and stir the pieces occasionally so they don’t form clumps.”
Under blanching the vegetables may actually stimulate the activity of the enzymes. This is worse than not blanching it at all. Blanching for too long, however, causes a loss of flavor, color, vitamins and minerals. Properly blanching not only helps preserve the flavor, but also helps to shrink some of the vegetables, making them ideal for packaging, killing bacteria and removing dirt. Once the vegetables are properly blanched, immediately move them to ice water to stop the cooking process. Keep them in the ice water for about three to four minutes.
While steam blanching is less reliable than water blanching, it is a recommended method for winter squash, pumpkin, broccoli and sweet potatoes. To steam the vegetables, place them on a rack 3 inches above approximately 1 to 2 inches of boiling water. Quickly cover the pot or steamer. The vegetables should steam for about five minutes, then immediately cool the blanched vegetables.
Brannon said in order to not dry out the food, people should package all vegetables in moisture and vapor-proof freezer containers.
“Pack the vegetable pieces tightly, removing as much air as possible,” she said.” Don’t freeze more than a half-gallon of vegetables in a container. Two of the most common freezer containers for vegetables are flexible bags or rigid containers.”
People can reuse rigid containers if they have properly taken care of them. Wash the containers in warm water to avoid potentially warping the lids. If the lid is no longer airtight, use freezer tape to securely seal the lid.
“When packaging vegetables in a rigid container, leave approximately ½ inch of headspace in dry packs,” Brannon said. “If cold water is added to vegetables, such as lima beans, snap beans or peas, leave approximately ¾ to 1 inch of headspace in the container.”
Plastic freezer bags are also acceptable containers to freeze vegetables in. Before freezing, remove as much air from the package as possible. Like when using the rigid containers, leave about ½ inch of headspace at the top of the bag so the vegetables can expand when frozen.
Labeling the bags with the vegetable type, date frozen and amount will help keep track of the freshness of the food.
Brannon said people should freeze vegetables as quickly as possible and at the coldest temperature.
“For the vegetables to stay fresh and to not lose their nutritive value, never let the freezer temperature get above 0 degrees F,” Brannon said.
Also, do not over pack the freezer as this too can alter the temperature. Add no more than 2 to 3 pounds of unfrozen food per cubic foot to a freezer. In these proper conditions, vegetables will last between eight to 12 months.
People can cook many frozen vegetables without thawing them. However, people may need to thaw vegetables such as broccoli, leafy vegetables and corn on the cob in the refrigerator in order for them to cook uniformly. Find more information about properly freezing garden vegetables on the Alabama Extension website, www.aces.edu.