University of Vermont Extension
Department of Plant and Soil Science
Dr. Leonard Perry, Extension Professor
University of Vermont
If you have a large freezer,
freezing vegetables right from the garden or local farm stand may be easier and
longer lasting than traditional storage methods. Most vegetables can be frozen quite
easily. Exceptions not to freeze are
green onions, lettuce and other salad greens, cucumbers, and tomatoes (except
for use in juices and cooking).
First you should stock containers
for freezing. Be sure to use ones
specifically for freezers, including plastic freezer bags and rigid plastic
containers. Products such as sandwich
bags, bread bags, and dairy containers wont work well for storage. They allow loss of moisture, which in turn
leads to brownish-white spots known as "freezer burn". Although dried-out produce isn't spoiled, it
is often tough with odd flavors.
Another important key to preserving
texture and flavor of frozen vegetables is "blanching" prior to
freezing. This is simply scalding
vegetables in hot water or steam for a short time to stop enzyme action. These enzymes in produce are responsible for
their growth and maturation, so must be stopped prior to freezing. Blanching times will vary with
vegetables. Too little time, and the
enzymes keep working. Too much time, and
the vegetables come out of storage overcooked.
To blanch in boiling water, lower a
pound of vegetables in a gallon of boiling water. If steam blanching, suspend a thin layer of
vegetables in a wire basket over one to two inches of boiling water in a
kettle. In the microwave, blanch two
cups of vegetables at a time with one-quarter cup of water in a two-quart
casserole. Cover with plastic wrap, not
a glass lid, to decrease
After blanching, cool quickly in a
large amount of cold water. Running
water or use of ice often helps. When
packing, since food expands, leave about a half-inch of space at the top in
rigid containers. In freezer bags, press
the air out of the bag before closing.
These methods are "solid pack" in which case you thaw the
whole container. If you freeze the
vegetables on a tray prior to packing, this method of "loose pack"
allows you to pour out vegetables as needed.
Here are some specific tips and
blanching times for popular vegetables.
beans should be blanched from 2 to 4 minutes, depending on size, with the least
time for the smallest beans. Green beans
can be left whole, or cut into short lengths.
Remove tips, and blanch for 3 minutes.
should be washed, sorted by size, and tops trimmed off but leaving a half-inch
of stem. Boil until tender—25 minutes
for small beets, more for larger. Cool,
slice or cube to freeze.
and trim broccoli into pieces one to one to two inches across. If you see insects, soak for a half hour in a
solution of 4 teaspoons of salt in a gallon of water. Blanch in water for 3 minutes, over steam for
5 minutes. Treat cauliflower the same.
for Brussels sprouts and cabbage, check and treat if needed for insects. Remove
coarse, outer leaves. Wash, and sort sprouts by size, blanching 3
to 5 minutes, more for larger ones. Cut
cabbage into shreds or wedges, then blanch for one and a half minutes.
tops of carrots, then wash. You can
leave whole, or cut into sections or strips.
Blanch whole carrots 5 minutes, diced or sliced carrots for 2 minutes.
corn can be left on the cob after husks and silks are removed. Blanch small ears 7 minutes, large ears 11
minutes. If cutting kernels off the cob,
blanch for 4 minutes.
peel, and cut eggplant into one-third inch thick slices. Soak in the above salt solution for
minutes to preserve color. Blanch for 4
you can't freeze salad greens, you can wash and blanch greens from beets,
collards, turnips, spinach, and others similar.
Blanch tender greens one and a half minutes, other greens 2 minutes,
except 3 minutes for collard greens.
wash, and dice fully mature onions.
Loosely pack in freezer bags without blanching.
green peas, then blanch for one and a half minutes. For snow peas, remove blossom ends and
strings, then blanch whole for one and half to three minutes depending on size.
or hot peppers should be washed, then cut into rings or slices and frozen
without any heat treatment.
peel, and cut potatoes into half-inch cubes.
Blanch for 5 minutes. For hash
browns, cook potatoes in jackets until almost done. Cool, peel, and cut into desired shapes to
summer squash or zucchini, then cut into one-half inch slices to blanch for 3
juice tomatoes, wash, sort by size, and cut into quarters. Simmer for 5 to 10 minutes, then press
through a sieve prior to cooling and freezing.
For stewed tomatoes, wash and scald for a minute to loosen the skin,
then peel and core. Quarter, simmer for
15 minutes, then cool. For raw tomatoes,
peel and core as above. Then quarter and put in containers, pressing down to
release the juice. Leave an inch of
headspace in containers of tomatoes for the juice.
When cooking frozen vegetables, keep
in mind all but corn on the cob (it should be partially thawed) should be
cooked without thawing. Since blanched
vegetables have been partially cooked, they'll need less time than fresh vegetables,
so cook only until tender.
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