Blanching your Produce

August 24, 2015 | Christine Hradek

fresh green beans cooking in a pot

We get lots of calls at AnswerLine from gardeners who are getting ready to freeze their vegetables. Blanching helps maintain the quality of garden produce and even experienced gardeners often ask us to review the directions for blanching as it has been a while since they did it last.

Blanching food is done for quality reasons, not safety reasons. Therefore, you do not need to blanch a food that you are freezing to keep it safe.  Blanching destroys enzymes that naturally occur in food so they won’t overly soften the food while it is stored in the freezer. In order to destroy enzymes, the food must be heated long enough to penetrate the flesh of the vegetable. The National Center for Home Food Preservation has a guide available with times for blanching various vegetables.

We advise callers to work with small batches of vegetables. Otherwise the food will be in the boiling water too long and will be over cooked. If you can use a basket to lower the food into the boiling water, you can easily remove it all at once. Then you can submerge the food in ice water to stop the cooking process. After the food has cooled, package and freeze it.

Steps for blanching food:

  • Bring a large pot of water to a boil.
  • Place a quart sized batch of vegetables in the water.
  • After the water returns to a boil (which should be within 1 minute), set the timer.
  • When time is up, plunge the vegetables into ice water.
  • Remove the vegetables and shake or blot excess water.
  • Package and freeze.

Remember that you should not put stacks of freshly blanched food into the freezer. Instead, spread the packages around inside the freezer. This allows the food to freeze quickly, which will give the best possible frozen food. You can also spread food onto a tray or cookie sheet with sides and freeze overnight. Package it the next day and the vegetables will not stick together—just like those you buy at the grocery store.

Happy gardening and happy blanching. Remember you can contact us with questions. You can reach us at 1-800-262-3804 in Iowa, 1-800-854-1678 in Minnesota, and 1-888-6336 in South Dakota. You can also call us at our local number 515-296-5883 if your area code is not from one of the above three states. Email us at or contact us on Facebook.

The AnswerLine staffAnswerLine

Liz, Beth, and Jill


Link for guide

Christine Hradek

Christine Hradek is a State Nutrition Specialist with Iowa State University Extension and Outreach. She coordinates ISU’s programs which help families with low income make healthy choices with limited food budgets. Christine loves helping families learn to prepare healthy foods, have fun in the kitchen and save money. In her spare time, Christine enjoys cooking, entertaining and cheering on her favorite college football teams with her family and friends.

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