Packaging Material
Material selected for packaging fruits and vegetables for freezing must be moisture-vapor-proof or moisture-vapor-resistant to keep the food from drying out and from absorbing odors from other foods in the freezer. Loss of moisture from the food causes small white areas called “freezer burn” to develop. These areas are not harmful, but if extensive they can cause the food to become tough and lose flavor.
Suitable packaging materials include rigid plastic food containers, plastic freezer bags, heavy aluminum foil, freezer paper or plastic film, glass freezer jars, and waxed freezer cartons. Collapsible, cardboard freezer boxes are frequently used as an outer covering for plastic bags to protect them against tearing.
Select packaging materials suiting the shape, size, and consistency of the food. Rigid containers are suited for freezing all foods, but are especially good for fruit packed in liquid. Non-rigid containers are best for fruits and vegetables packed without liquid. Paper, plastic, or foil wraps are ideal for freezing bulky vegetables such as broccoli, corn on the cob, and asparagus.
Rigid containers with straight sides and flat bottoms and tops stack well in the freezer. They take up less freezer space than rounded containers, containers with flared sides, and bulky, wrapped packages or plastic bags without protective outer cartons. Containers with straight sides or those that are flared, having wider tops than bottoms, are preferred for easy removal of the food before thawing. If the opening is narrower than the body of the container, the food will have to be partially thawed so you can get it out of the container.
Freezer containers and bags are available in a variety of sizes. Do not use those with more than ½-gallon capacity for freezing fruits and vegetables since the food will freeze too slowly, causing poor quality food.
Choose a container that will hold enough food for one meal for your family. You may wish to put up a few smaller packages for use when some family members are not home or to go with your family-size packages when guests are present for meals.
Pack foods tightly into containers. Since most foods expand during freezing, leave headspace between the packed food and closure.
For fruits that are in liquid, pureed, or crushed and packed in containers with wide openings, leave ½-inch headspace for pints, 1-inch headspace for quarts. If containers with narrow openings are used, leave ¾-inch headspace for pints, 1½-inch headspace for quarts.
For fruits and vegetables packed without liquid, leave ½-inch headspace for all types of containers. Vegetables that pack loosely, such as asparagus and broccoli, require no headspace.
Any container for freezer use must be capable of a tight seal. Rigid containers should have an airtight-fitting lid.
Press out all air from the unfilled parts of plastic bags. Immediately twist the top of each bag and securely tie it with a paper- or plastic-covered wire twist strip, rubber band, or string to prevent return of air to the bag.
Some bags may be heat-sealed with special equipment available on the market. Follow the manufacturer’s directions.
Edges and ends of paper, foil, or plastic wraps should be folded over several times so the wrap lies directly on top of the food and all air has been pressed out of the package. Seal the ends with freezer tape to hold them securely in place.