Summer is still providing ample cultivated and wild berries and vegetables. While you may preserve these by canning, freezing might be a quicker and easier method if you have an abundance of berries or vegetables and little time. And, you can use previously frozen products for canning later – people often do this with fish and berries.
Freezing can keep foods safe for a long time but quality will deteriorate without a few key techniques. One of these is to freeze your product solid as quickly as possible – this means putting packaged food into the freezer in a single layer and not over loading the freezer. The longer your food takes to freeze, the larger the ice crystals; and, large ice crystals lead to a mushy product (think mushy fish or broccoli). For some foods like snap peas, cauliflower or broccoli florets, freezing in a single layer on a tray and then putting them into freezer bags will allow you to later remove just the amount that you need for a single serving, while keeping the rest frozen. Keep you freezer on the coldest possible setting – the colder the temperature, the longer your food will retain it’s quality.
A second tip is to make sure that you freeze products with as little air as possible in “freezer grade” packaging – many different types of packaging will work but it must be able to withstand the cold temperature without cracking and it must be able to exclude air. Thin plastic, not designed for the freezer, will allow the product to dry out or take up odors from the freezer.
Most garden vegetables or even wild greens also require a step called “blanching” for best long-term storage. “Blanching” means placing the vegetable in boiling water for a brief period and then quickly cooling it down in an ice water bath before freezing. This step destroys enzymes in the fresh vegetables that cause a loss of flavor, nutrients and color. It can also help to destroy any germs on the food. Many people don’t like the idea of cooking their vegetables before freezing but it definitely helps preserve the quality and even the nutrients of your vegetables. The USDA has published recommended times for blanching different vegetables.
Call your local Cooperative Extension Service to get more information about freezing and blanching times. You might also check on-line for University of Alaska Fairbanks Cooperative Extension food preservation publications or the National Center for Food Preservation (nchfp.uga.edu).
Leslie Shallcross works at the UAF Cooperative Extension Service and is a well-known expert on cultivating, foraging, and preserving Alaskan foods.