For freezing vegetables, you'll use a similar technique, but apply a little heat first. Carol Ann Burtness, MEd, with the Minnesota Extension Office, says her favorite preserving tip is to briefly blanch the vegetables, drain them, spread them out in a single layer on a cookie sheet, and place it in the freezer.
"After vegetables are frozen solid (2-3 hours), transfer vegetables to a freezer-safe plastic bag and keep them in the freezer until needed," she says.
The blanching step inactivates enzymes in fresh produce that can cause changes in color, nutrient content, and flavor when frozen. It also helps destroy microorganisms on the surface of the vegetables, according to the University of Minnesota Extension Service.
To blanch vegetables for freezing, follow these steps:
- Use about 1 gallon of water for each pound of vegetables.
- Bring water to rolling boil.
- Submerge a wire basket containing the vegetables into the boiling water.
- Boil briefly (depending on the vegetable, about 1 to 2 minutes)
- Lift the basket and cool vegetables immediately in ice water (to prevent further cooking) then drain the vegetables thoroughly.
- Follow the steps for the dry pack freezing technique above.
Some microwaves offer directions in their manuals on blanching vegetables. Refer to your manual for times and directions because the power levels vary among different brands and types of microwave ovens.
And don't forget: when you're ready to use your frozen vegetables, cook them only until just tender. (Your cooking time will usually be about half as long as if the vegetables were fresh.) This way, the color will be brighter and the texture firmer.
Freezer Jams and Preserves
When it comes to uncooked freezer jams, it's all about the berries! According to the University of Minnesota Extension Service, raspberries, strawberries, and blackberries work best in uncooked freezer jam recipes. Uncooked jams can be safely stored in the refrigerator for several weeks or up to a year in the freezer. (Check out the recipe for Strawberry Orange Freezer Jam below.)
If you want to cut down on sugar in your jam or fruit preserves, you can buy packages of pectin made especially for "less sugar" or "no sugar" recipes (they work for freezer recipes as well as cooked ones). Sure-Jell and Ball Fruit Jell are the two brands available in most supermarkets. Inside each box is an instruction sheet. Don't lose this; it's your go-to guide for making your less-sugar jam.