All About Blanching
Freezing food is one simple method of preserving food at home. However, sometimes its not as simple as throwing a ziploc bag of veggies in the freezer. This is when blanching comes in as a way of preserving and cleaning the food.
According to the National Center for Home Food Preservation (NCHFP), blanching vegetables refers to "scalding vegetables in boiling water or steam for a short time." Blanching vegetables prior to freezing is necessary because the process "stops enzyme actions which can cause loss of flavor, color and texture." Not only that, blanching also removes any small particles of dirt or microorganisms from the surface of the food that may remain after washing. Additionally, blanching veggies before freezing can actually help your food retain vitamins and minerals.
The NCHFP recommends following their chart for blanching times when preparing vegetables for freezing. "Underblanching stimulates the activity of enzymes and is worse than no blanching," their site reports. "Overblanching causes loss of flavor, color, vitamins and minerals."
All vegetables, from green beans to carrots to okra, should be blanched before they are frozen for storage. Not only will the texture of your vegetables be improved when eaten out of the freezer, you can be sure that bacteria, fungus, and mold have not spoiled your frozen food. Although they move and multiply very slowly, remember that microorganisms can still live on your veggies in the freezer.
Blanching vegetables in the microwave is not recommended by the NCHFP. Follow the instructions below on boiling water blanching and steam blanching.