NPR logo Freezer Jam: A Baby Step To Canning

Freezer Jam: A Baby Step To Canning

Jars of jam ready for the freezer i
Stephanie Stiavetti for NPR
Jars of jam ready for the freezer
Stephanie Stiavetti for NPR

For years I researched the art and craft of preserving summer fruit, but I could never bring myself to go ahead and try it myself. What if I did something wrong? What if my jars exploded in the heat? What if I hurt myself or someone I cared about?

These "what-ifs" kept me mired in doubt and dismay while many summers passed, taking their bounty of fresh fruit with them. When winter inevitably followed, I always regretted my fear of canning and planned a bevy of canning projects for the following year — which, of course, never happened.

Welcome to my vicious cycle. I have, however, broken through my preserving paranoia so that I can enjoy peaches, nectarines and strawberries all year long. I found a baby step on the road to heat-processed canning: freezer jam.

The first summer I made freezer jam, I enjoyed it so much that I preserved everything I could get my hands on. Peaches, plums, nectarines, blueberries, raspberries, you name it. I lined my freezer with row after row of colorful jars, many of which made their way home with friends after dinner parties and high-tea afternoons. Well into February I had fresh, homemade jam every morning to spread on my toast and mix into my homemade yogurt.

Making freezer jam follows the same process as heat canning, with one primary thing missing: heat. Since you store freezer jam below zero degrees, you don't need to bring the jars to a boil, which means you lessen the chances of accidental contamination or heat-related mishaps. These two risks prevented me — and many others, I've learned — from traditional canning, and I was overjoyed to find that I could make my own jam without the element of danger that goes along with sterilization and storing at room temperature.

Besides mollifying your canning phobia, there's another benefit to not boiling your jam. Uncooked fruit stays much fresher than cooked preserves, so when you crack open your treasure in mid-January, it will taste more like the fresh summer fruit you picked up from the farmers market. Some brands of pectin require that you use boiling water in the initial mix, but this short stint on the stove won't affect the flavor or texture of your fruit.

Most freezer jam recipes contain only three or four ingredients and require half an hour or less for preparation. It's a simple process: peel, chop, mix and freeze. The safety and simplicity of freezer jam makes it a perfect kitchen project for children, who love the idea that they made the tastiest part of their peanut butter and jelly sandwiches.

Since I started making my own fruit preserves, I've also noticed that I spend less money on produce. Grocery stores and farmers market booths usually sell me their slightly bruised fruits for pennies on the dollar, and this substantially cheaper bounty lasts me all year long, shrinking both my summer and winter grocery budgets. For jam-making, get fruit that is as ripe as possible. Slightly bruised or dinged fruits are fine to use — in fact, this is what makes them cheaper — but you should remove any spots with a paring knife, taking care to remove any mold.

About The Author

Stephanie Stiavetti is a food writer in the San Francisco Bay Area. A self-proclaimed literary gastronaut, she spends most of her time thinking about, reading about or writing about food. She can usually be found perusing the cookbook section of used bookstores and posting on her food blog, Wasabimon, or on Twitter under the username "sstiavetti."

If you have children in the house, you might also notice yourself spending less on lunch fixings because decent store-bought jam demands a pretty penny these days. When I make freezer jam, the cost comes out to around 50 cents per 8-ounce container, and I have to say that the taste of homemade jam blows grocery store brands out of the water.

Making freezer jam is easy, but there are a few things you should keep in mind when you make your first few batches. Follow these tips to keep from repeating my mistakes.

Pectin is the fruit-derived gel that holds jam together and creates a thick consistency. It's important to buy a brand of pectin that is compatible with no-cook freezer jam. Read the instructions carefully, as recipes can (and will) vary from brand to brand. Different kinds of pectin call for different amounts of sugar, so read the directions or your jam won't set correctly. Freezer jams always run a touch thinner than heat-processed preserves, but they should still set to a nice, spreadable consistency. If you prefer a thicker jam, you can heat your fruit to a boil for two minutes before freezing.

When making the recipes below, I used Ball No-Cook Freezer Jam Pectin, with which I've always had good experiences. You can also use any number of other brands, and these days many kinds of pectin allow you to use alternative sweeteners such as honey or Splenda, which is good news for those avoiding refined sugar.

If you do decide to use granulated sugar, it's a good idea to use a superfine variety so that it will dissolve more easily into your fruit. Instead of spending extra money on a specialized product, make it yourself by pulsing regular sugar in a food processor five or six times. Be sure to measure your sugar before grinding it, as it will yield a greater amount once the granules are broken down, and adding extra sweetener may cause your jam to be too sweet.

While you can purchase special plastic containers made for storing jam in the freezer, it's not necessary. You can use whatever sealable plastic containers you have hiding in your cupboards, or you can use good, old-fashioned Mason jars. I usually go with the jars because the whole point of this exercise (for me, anyway) was to act as a precursor to heat canning, and nothing invokes the memory of my grandmother's summer jam more than cute, 8-ounce glass jars with a ribbon tied around the top.

If you decide to use Mason jars, a word of caution: Do not use glassware with "shoulders," or a curvature in the jar just beneath the lid. Instead, use straight-sided jars with a wide mouth. When you freeze liquids, they expand inside the container and push against any curves or shape differences. In the case of glass jars, this can cause breakage and a sticky, razor-sharp mess in your freezer.

After a summer of making freezer jam, I was finally comfortable enough with the process to attempt heat canning. My first batch of preserves, an elderberry-peach recipe that I made up on the fly, came out perfectly and completely free of mishap. While these days I'm much more comfortable with heat-processed canning, I still make freezer jam so that I can preserve the freshness of certain fruits that taste better uncooked. It is still a staple in my house.

Strawberry-Nectarine Jam

Kids love the deep orange color of this fruit spread, while adults appreciate the low-sugar tartness that makes for a great grown-up peanut butter and jelly sandwich. Because freezer jams are not sterilized, you cannot keep them at room temperature.

Strawberry-Nectarine Jam i
Stephanie Stiavetti for NPR
Strawberry-Nectarine Jam
Stephanie Stiavetti for NPR

Makes enough to fill five 8-ounce jars.

2 1/2 cups nectarines, peeled, pitted and chopped (about 2 1/2 pounds)

1 1/2 cups strawberries, cored and chopped finely (about 1 pound)

2 tablespoons lemon juice

1 cup sugar, ideally superfine

Pectin of your choice (since it varies by brand, consult package for correct amount)

In a large bowl, crush nectarines with a potato masher until you have a chunky consistency. The goal is to release a small amount of liquid while keeping mostly good chunks of fruit pulp to give your jam a thicker texture. Add the strawberries and crush a little more, just enough for the strawberries to release some juice and mix with the nectarines. Add lemon juice and mix with a spoon for 30 seconds.

Prepare sugar and pectin according to package directions. They may call for you to add sugar directly to the fruit first, or you may need to add the sugar to the pectin before mixing both into the fruit at the same time. Regardless, make sure that when you add the pectin to the fruit, you stir constantly for at least 3 minutes. Pectin can create lumps in your jam if it's not carefully mixed in, and the only way to prevent this is by stirring relentlessly.

Fill clean jars with jam, leaving about 3/4-inch of headroom so that the jam has room to expand in the container. Store in the freezer for up to 6 months, or in the refrigerator for 1 week.

Citrus Pear Jam

Late-season pears get a boost from a touch of orange and cardamom in this tasty recipe, which goes just as well spread on toast as it does over roast pork tenderloin. Because freezer jams are not sterilized, you cannot keep them at room temperature.

Citrus Pear Jam i
Stephanie Stiavetti for NPR
Citrus Pear Jam
Stephanie Stiavetti for NPR

Makes enough to fill five 8-ounce jars

2 medium-sized sweet naval oranges

3 cups ripe Bartlett pears, peeled, seeded and chopped finely

1 tablespoon lemon juice

1/4 teaspoon ground cardamom

1 1/2 cups sugar, ideally superfine

Pectin of your choice (since it varies by brand, consult package for correct amount)

Using a sharp knife, completely remove the peel of the orange. One at a time, remove each slice of orange, using the knife to cut between the orange flesh and the white pithy membrane that separates each slice. When you're done, you should have perfectly formed orange slices without any seeds or membranes. If any seeds remain, remove them. Cut each slice into 3 or 4 chunks. Place them in a bowl and mash gently with a fork until you have a pulpy consistency, and set aside. You should have 1 cup of orange chunks.

Place 1 cup of chopped pears in a bowl, reserving the rest. Sprinkle cardamom on the pears in the bowl and, with a potato masher, crush until you have a thick, chunky consistency. Add the rest of the pears, crushing a little more to gently break up the chopped bits. Mix in lemon juice.

Prepare sugar and pectin according to the package directions, making sure to stir constantly for at least 3 minutes when you mix it into the fruit. Fervent stirring will prevent lumps from accumulating in the jam.

Ladle jam into jars, leaving 3/4-inch of headroom to allow for expansion. Store jars in the freezer for up to 6 months. In the refrigerator, jam will keep for one week.

Spiced Autumn Preserves

Perfect for breakfast rolls or over ice cream, this recipe is a lovely way to hold on to late summer's deluge of fresh fruit while preparing for cold mornings. Because freezer jams are not sterilized, you cannot keep them at room temperature.

Spiced Autumn Preserves i
Stephanie Stiavetti for NPR
Spiced Autumn Preserves
Stephanie Stiavetti for NPR

Makes enough to fill five 8-ounce jars

1 1/2 cups apples, peeled, cored and chopped

1 1/2 cups Asian apple pears, peeled, cored and chopped

2 tablespoons lemon juice

1 cup plums, peeled and chopped

1/2 teaspoon cinnamon

1/8 teaspoon ground cloves

1 1/2 cups sugar, ideally superfine

Pectin of your choice (since it varies by brand, consult package for correct amount)

In a large bowl, crush apples and pears with a potato masher until they are about halfway pulverized. You should still have soft chunks of fruit, but nothing larger than a half-inch. Using a spoon, stir in lemon juice until it is well combined.

In another bowl, gently crush plums until they have a similar texture to the apples and pears. Pour plums into apple mixture and stir well with a spoon. Mix in cinnamon and cloves, stirring until completely incorporated.

Prepare sugar and pectin according to the package directions. When you mix the pectin into the fruit, make sure to stir for at least 3 minutes. Lumps are a common pitfall for beginning jam makers, and vigorous stirring will prevent them from forming.

Fill jars with jam, making sure to leave 3/4-inch at the top so that it can expand. Store in the freezer for as long as 6 months. Once jam is defrosted, it will keep up to a week in the refrigerator.



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