What Is Blanching Food?

Blanching vegetables is part of the process of preserving them.

Blanching is a necessary part of the process for freezing vegetables and is also used to refresh wilted vegetables for preparation in the immediate future. Blanching fresh vegetables, then refrigerating them and serving as crudités or using them for sautéed dishes, guarantees bright color and crisp texture. When blanching prior to freezing or for any purpose, follow the blanching directions closely so the color, vitamins and texture of the vegetables are maintained.

Purpose

Freezing food successfully requires blanching to stop the enzymatic reaction within the tissue of the plant that causes it to decay. Blanching also cleans the plant of surface debris while at the same time killing bacteria present even after thorough washing. The blanching process retains the vegetable's color and helps prevent the loss of vitamins while softening the food so it packs more efficiently for freezing.

Water Blanching

The most effective way to blanch vegetables is to have a blancher unit consisting of a large pot with a wire basket that fits into it and a tight-fitting lid. The general rule is to blanch 1 lb. of vegetables for each gallon of lightly salted water in the pot. The vegetables are loosely packed in the basket and lowered into rapidly boiling water. The lid is quickly fitted on tightly and the time count begins immediately. Different vegetables require different times of immersion; consult the directions for the time for the particular type of vegetable being blanched.

Steam Blanching

Once again, blanch 1 lb. of vegetables for each gallon of water in the pot. Place enough water into the pot so that there is room enough for the bottom of the basket to be suspended 3 inches above the surface of the water. Lay the vegetables single layer in the basket so the steam can envelope it completely and lower the basket into the pot. Immediately place the lid on the pot and start the countdown, usually about 30 to 90 seconds, depending on the vegetable being blanched.

Cooling Blanched Vegetables

Whether water immersion or steam blanching is used, the moment the time count is up, the basket is raised from the pot, quickly drained of surface water and plunged into an ice bath. The ice bath must be maintained at a temperature of 60 degrees Fahrenheit or below for each immersion. This is accomplished by using a large dunking space, such as a kitchen sink or large tub, draining the water as needed and replacing it with ice water. Use the water even after it becomes cloudy since the repeated draining and addition of fresh cold water keeps it clean. Cooling the vegetables takes about the same amount of time as blanching them.

References

• MissouriFamilies.org
• New Mexico State University; Drying Foods; Nancy C. Flores
• National Center for Home Food Preservation: Blanching