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Extension > Food > Food Safety > Preserving and Preparing > Vegetables and Herbs > Vegetable blanching directions and times for home freezer storage

Vegetables and Herbs

blanching pot

Vegetable blanching directions and times for home freezer storage

By Carol Burtness, Extension Educator — Food Safety

Revised 2015 by Suzanne Driessen, Extension Educator — Food Safety.


Blanching is a must for most vegetables to be frozen. It slows or stops the enzyme action which can cause loss of flavor, color and texture.

The blanching time is very important and varies with the vegetable and size. Underblanching stimulates the activity of enzymes and is worse than no blanching. Overblanching causes loss of flavor, color, vitamins and minerals.

Blanching directions:

  1. Wash, drain, sort, trim and cut vegetables.
  2. Use one (1) gallon water per pound of prepared vegetables or two (2) gallons water per pound leafy greens.
  3. Put vegetables into blancher (wire basket, coarse mesh bag or perforated metal strainer) and lower into boiling water; Or steam blanch - boil 1-2 inches of water in a pot, bring to boil, then put a single layer of vegetables in basket.
  4. Cover. Start counting blanching time as soon as water returns to a boil or immediately if steam blanching.
  5. Keep heat high for the time given in the directions.
  6. Cool immediately in ice water or cold water (60°F or below) for the same time used in blanching (except for corn-on-the-cob - see below)*. Stir vegetables several times during cooling.
  7. Drain vegetables thoroughly.
  8. Pack the vegetables either by dry pack or tray pack.
    • Dry Pack: Pack vegetable tightly into containers or freezer bags. Press out air and seal tightly.
    • Tray Pack: Put a single layer of the vegetable on a shallow pan and put the pan into the freezer. As soon as the vegetable is frozen, put them into a freezer bag or container. Press out air and seal tightly.
  9. Freeze.
  10. Frozen vegetables will maintain high quality for 8 to 12 months at 0°F or lower.

Vegetables blanching times

Vegetable blanching times (water blanching)

Vegetable Blanching time (minutes)
In boiling water
In steam
Asparagus: 2 3
Small stalk 2 3
Medium stalk 3 5
Large stalk 4 6
Beans - Snap, Green or Wax 3 5
Beans - Lima, Butter or Pinto:
Small 2 3
Medium 3 5
Large 4 6
Broccoli (flowerets 1 1/2 inches across) 5
Brussels Sprouts:
Small heads 3 5
Medium heads 4 6
Large heads 5 7
Cabbage or Chinese Cabbage:
Shredded 1 1/2 2 1/2
Carrots:
Small, whole 5 8
Diced, sliced or strips 2 3
Cauliflower (flowerets, 1 inch) 3 -
Celery 3 -
Corn:
Corn-on-the-Cob small ears 7 10
Corn-on-the-Cob medium ears 9 13
Corn-on-the-Cob large ears 11 16
Whole kernel or cream style (ears blanched before cutting corn from cob) 4 6
* Cooling time for corn-on-the-cob is twice the time of blanching.
Eggplant 4 6
Greens:
Collards 3 5
All other 2 3
Kohlrabi:
Whole 3 -
Cubes 1 -
Mushrooms:
Whole - 9
Buttons or quarters - 9
Slices - 5
Okra:
Small pods 3 5
Large pods 4 8
Onions (blanch until center heated): 3-7 -
Rings 10-15 seconds -
Peas - Edible Pod 2-3 -
Peas - Green 1 1/2 - 2 1/2 3-5
Peppers - sweet:
Halves 3 5
Strips or rings 2 3
Potatoes - Irish (New) 3-5 5-8
Rutabagas 3 5
Soybeans - Green 5 -
Squash - Summer 3 -
Turnips 3 5
University of Minnesota Extension, So Easy to Preserve, 6th Edition, University of Georgia, 2014

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Related resources

University of Minnesota Extension - Food Safety
National Center for Home Food Preservation

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