Freeze berries now to savor summer later

Freezing strawberries, raspberries, and blueberries in season is faster, easier, and more hands-off than canning. Freezing strawberries, raspberries, and blueberries in season is faster, easier, and more hands-off than canning. (iStock)
By Diana Burrell
Globe Correspondent / June 23, 2010

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Yes, strawberries, raspberries, and blueberries can be too much of a good thing, especially when you return from the local pick-your-own farm and realize there are only so many you can eat before they start to lose their luster.

Set aside the most perfect berries to eat now and stash the rest of your haul in the freezer. One benefit to freezing fruit: You can get away with freezing less-than-perfect specimens, such as strawberries with bruises that can be cut away or slightly overripe berries. Not so with canning, which requires pristine fruits at the perfect stage of ripeness. Which brings us to another advantage of freezing over canning: it’s faster, easier, and hands-off. In some cases, you can put washed and dried berries in a zipper bag and pop it into your freezer without further prep. Here are some hints for freezing your bounty.

First, choose a freezer container that works for your space and best protects your berries. What makes the best storage container for frozen fruit comes down to a matter of personal preference. Plastic zip-top freezer bags can be stored flat, or molded around other items in the freezer. (Plus, a bag of frozen blueberries or raspberries makes a great makeshift cold pack for a child’s bump or bruise.) Just add the fruit to the bag, squeeze as much air out as you can, and seal.

Air is the enemy of frozen food, so some swear by vacuum sealers to remove all the air, but quality on these machines is spotty. They require proprietary heat-sealable bags, which can be expensive. Another solution is to use freezer-safe plastic containers, like Ikea’s Pruta food saver containers ($4.99 for a set of 17 pieces, plus lids). The square- and rectangular-shaped containers are space efficient, and you can pick the right-size container for your produce.

Since some home cooks don’t like plastic in their kitchens, glass containers like Mason jars make good storage for frozen berries. Be sure to leave a couple inches of head space in the jars, especially if you’re freezing sliced or chopped berries as the fruit will expand when frozen. However, the round shapes of glass jars aren’t as space-efficient as square or rectangular shapes. Plus they can break in the freezer, leaving shards of glass everywhere.

To prepare strawberries for freezing, rinse and dry the berries thoroughly, then cut away stems and hulls. If the berries feel mushy or are starting to mold, they’re only suitable for the compost pile, so check them over carefully. If you think you’ll be using some of your berries chopped or sliced for a recipe, now’s the time to make your cuts.

“The cold temperatures are a terrific way to preserve summer flavor, but will soften the fruit too much for any post-chill prep,’’ says Sherri Brooks Vinton, author of “Put ’em Up!: A Comprehensive Home Preserving Guide for the Creative Cook.’’

With raspberries and blueberries, simply rinse and dry the berries, foregoing the chopping, then tip them into a freezer bag or container before placing in deep freeze.

If you want to be able to pull out a few frozen berries for smoothies, pancakes, or muffins, you’ll need to freeze the fruit before it goes into a bag or container. If you pile your berries in a bag or container and freeze them, you’ll be stuck with a big block of frozen fruit when you pull it out. Instead, take a page from the frozen food industry and freeze the berries in a single-layer on a rimmed baking sheet. When the individual fruits are frozen solid, tip them into freezer bags or containers. (The process is called individually quick frozen or IQF.) When it’s time to use them, grab the amount you need. There’s no need to defrost frozen raspberries or blueberries if you’re using them in baked goods. If you’ve presliced or chopped your fruit, the IQF process won’t work, so freeze this fruit in appropriate-size containers.

Before you stack any of your containers in the freezer, mark them with the date and the contents. According to David Nyachuba, assistant professor at the University of Massachusetts Amherst’s Department of Nutrition and director of the UMass Extension Food Safety Education Program, frozen foods, including berries, remain safe indefinitely. However, the quality deteriorates over time, so berries should be used within six months.

“Put ’em Up!’’ author Vinton agrees. “After that they start to taste more of the fridge than the summer.’’

To find Ikea Pruta containers, go to

Diana Burrell can be reached at