Saving Summer: 3 Ways to Preserve Blueberries

Blueberries, native to North America, are a healthy, versatile, and delicious summer favorite. (FamVeld/Shutterstock)

Blueberry season is in full force across the country. These sweet—yet not too sweet—and tart—yet not too tart—berries are one of our household favorites. We love them so dearly that we finally added blueberry bushes to our front yard gardens this year, so that we can have them at our fingertips just as soon as they ripen.

To extend the harvest, we always make sure to freeze a few quarts each summer. Frozen berries can be used in baking, added to smoothies, or simply enjoyed as a sweet treat (they’re one of my daughter’s favorite snacks).

To freeze blueberries, rinse them with cold water, strain, and discard any bruised or damaged ones. Line a cookie sheet with a clean dish towel and lay the berries out in a single layer so that they can fully dry. Once completely dried, transfer them to a large freezer bag (or canning jar, or a plastic container with lid), seal tightly, and freeze. As long as the berries don't have any moisture between them, they won’t stick together during the freezing process. This will allow you to easily scoop out the amount you desire, without thawing out the entire container.

Let your blueberries dry completely before freezing, and they won't stick together. (Pixel-Shot/Shutterstock)

No room in the freezer? Wash the berries with a vinegar and water solution to extend their fridge life. My aunt uses this method for all her fresh berries and swears by it. Fill a bowl with about 1 quart of cold water and mix in about 2 tablespoons of white distilled vinegar. Allow the berries to soak for 5 to 10 minutes. Discard any bruised or damaged berries. Drain, rinse, and strain, then spread them out on a towel-lined cookie sheet to fully dry. Store in a paper-towel-lined container with a lid and refrigerate.

This process cleans away mold spores and bacteria that cause them to deteriorate at a quicker rate. Berries should last up to two weeks after the vinegar soak if done properly. Refrigerating the berries quickly after harvest also plays a part in their longevity, as nutrients begin to weaken as soon as they're harvested.

Thinking beyond the fridge and freezer, I’m sharing three of my favorite ways to preserve blueberries: jammed, fermented, and infused.

Blueberry jam, a classic flavor, is one of the easiest jams to make, ideal for the beginner canner. It’s delicious spread over toast, dolloped over a soft cheese on a cracker, used as a glaze over protein, or mixed with white wine vinegar and oil to make a vinaigrette. If you aren't into canning, you can skip the boiling pot and make a refrigerator jam instead.

Fermented fruits and vegetables are also some of the easiest preserves to make, often only requiring two ingredients: the produce and salt (or a saltwater brine). Fruits ferment more quickly than vegetables because of their high sugar content. Sweet and tangy fermented blueberries can be used in many of the same ways you’d use fresh or cooked ones—in yogurt, oatmeal, salads, and so on—but in our house, we prefer to use it as a condiment that we spoon over spicy, grilled jerk chicken.

Finally, there’s blueberry-infused gin—hello, happy hour. You’ll never buy infused alcohol again once you start making your own. Not only is it easier on the pocketbook, but the flavor is also so much better when you use real, fresh ingredients. To enjoy this gin, simply add two ounces of it to an ice-filled lowball and fill the rest of the glass with ginger beer, tonic water, prosecco, or sparkling water. Stir together and serve. Garnishing the cocktail with edible flowers isn't required but is definitely a nice touch.

Whether you go the canning route or simply make refrigerator jam, blueberry jam is a classic. (Stephanie Thurow)

Blueberry Jam

Makes 4 (8-ounce) jelly jars

• 2 pounds fresh blueberries (about 6 cups)
• 2 cups white granulated sugar
• 2 tablespoons lemon juice

Wash the blueberries and remove stems, as well as any bruised or flawed berries. Add the blueberries to a large, heavy-bottomed, nonreactive pot and use a potato masher to slightly break them down. Stir in the sugar and lemon juice. Bring the ingredients to a boil, then reduce heat to medium-high and simmer for 20 minutes until the jam begins to thicken. Stir often to avoid burning.

Water bath canning instructions: Ladle the hot jam into warm prepared jars (jars that have been washed and kept warm prior to filling), leaving 1/4-inch headspace (room from the top of the jam to the rim of the jar). Wipe the rims of the jars clean and place the canning lids on the jars. Screw the rings on the jars until they’re fingertip tight—just snug on the jar, not fully tightened.

Carefully lower the jars into a hot water bath so they’re completely submerged and covered with 1 to 2 inches of water, and cover with the lids. Turn the heat to high. Once the water begins a rolling boil, set the timer and process in the water bath for 10 minutes. Adjust cooking time for altitude as needed.

Once water bath processed, carefully remove the jars from the hot pot with canning tongs. Place the jars on a towel-lined surface for 12 hours without touching. After 12 hours, remove the jar rings and test to make sure that the lids have securely sealed onto the jars. Label and date the jars. Jam will keep for at least one year in the cupboard. Refrigerate after breaking the seal.

Refrigerator instructions: If you prefer to skip the water bath canning process, fill the jars with jam and allow them to cool on the countertop. Wipe the rims of the jars with a clean towel, add the canning lids, and tightly screw on the rings. Refrigerate. For best flavor, enjoy the jam within one month.

Recipe adapted from “Can It and Ferment It” with permission from Skyhorse Publishing Inc.

Fermented blueberries require only two ingredients: the berries and kosher salt. (And some time.) (Stephanie Thurow)

Fermented Blueberries

Makes 1 pint

• 2 cups fresh blueberries
• 1 teaspoon kosher salt

Wash and strain blueberries, and discard any bruised or flawed berries. Add the blueberries and salt to a clean pint jar. Wipe the rim of the jar with a clean towel, add the canning lid, and tightly screw on the ring. Shake the jar to mix the salt within the berries. Ideally, use a fermentation jar weight to push the berries down in the jar (without crushing them) so that once the natural brine is created, it will keep the berries submerged. (Without a jar weight, use a smaller canning jar that fits snugly into the mouth of the pint jar, filled with water.)

Keep at room temperature and out of direct sunlight. Once a day, unscrew the canning ring to “burp” the ferment, so that the built-up gasses created during fermentation can release. Push down the jar weight as needed so that the berries are once again submerged.

Ferment for three days and taste test. If the blueberries have reached your desired sour-tangy flavor, transfer the jar to the refrigerator. If they still taste too much like fresh berries, allow them to ferment another day, and taste test again until they reach your liking.

For the best texture and flavor, enjoy this fruity ferment within two weeks.

Blueberry-infused gin will give your G&Ts an extra-summery spin. (Stephanie Thurow)

Blueberry-Infused Gin

Makes 2 cups

• 1 cup fresh whole blueberries
• 2 cups gin of choice (I recommend using a mid-range gin)

Wash and strain the blueberries, and discard any bruised or flawed berries. Add the blueberries to a clean pint jar and pour gin over the berries until the jar is filled. Wipe the rim of the jar with a clean towel, add the canning lid, and tightly screw on the ring.

Store at room temperature and out of direct sunlight. (We store our infused liquors in the cupboard with the rest of our liquor.) As it infuses, the fruit will lose color and become pale, and the alcohol with become colorful. Tip the jar upside down every few days to blend the infusion.

Allow the fruit to infuse with the alcohol for at least two weeks before enjoying. The longer it infuses, the more flavorful it will become. Once infused, you can either leave the fruit in the gin, or strain it out—it’s up to you. You can strain the infusion through cheesecloth or a coffee filter to get a cleaner end product.

Recipe Notes

If you want to experiment with other flavor combos, I generally stick to the rule of 1 cup of fruit for every 2 cups of alcohol.

You can speed up the process of infusing flavors by cooking the berries, but I much prefer the flavor of a slow infusion with fresh berries. Once heated, the blend begins to taste more like jam than fresh berries.

Recipe adapted from “WECK Small-Batch Preserving” with permission from Skyhorse Publishing Inc.