How to make and can perfect strawberry jam

Published 9:00 pm Tuesday, June 12, 2007

There are great black holes in my pantry where last season’s bounty of shimmering preserves, tasty relishes and succulent jams once stood.

My secret cache of peerless red raspberry jam – the perfect just-because gift – is down to one jar. Dilly beans bit the dust months ago.

My husband is conscious of the erosion and has laid claim to the remaining quarts of damn good garlic dills and Oregon strawberry jam, while my mother has reminded me that she’s Completely out! of my apricot jam.

Indeed, it’s hard to let go of something special. Near impossible when it goes so well with the morning toast. But along with June’s strawberry crop – ripening to perfection at this very moment – comes the happy realization that a new preserving season is upon us.

Soon enough, a dizzying display of fresh local produce will tumble from the fields, and once again we will be caught up in the frenzy of capturing the harvest.

If you’re a newcomer to the preserving scene, I’m here to help. Dauntless canning is my aim. In the months ahead, I’ll be merging all sorts of preserving tidbits into my regular columns. I’ll break down worrisome phrases – what the heck’s a jelly stage? – keep you updated on preserving research, and provide well tested and delicious recipes and hints.

But for now, it’s time to get a little sparkle into your pantry. For starters, I’d like to help you get a batch of strawberry jam under your belt. There’s nothing like a gleaming collection of canning jars, freshly filled with ruby-tinted preserves, to instill confidence and make a canner proud.

So I’m going to start off with two strawberry jam recipes. They’re both straightforward and produce stunning results. But the one that calls for “added pectin” is particularly uncomplicated.

“Added pectin” is one of those pesky phrases I promised I’d dissect. It simply means that the recipe uses commercially made pectin instead of relying simply on the natural pectin within the fruit. For beginning canners, it’s pretty much a guarantee that you’ll get a lovely gel instead of syrup or, more disappointing, a rigid fruit clump.

Of course, for more seasoned canners or those who are more experimental by nature, please do try the other recipe, Jan’s exquisite strawberry jam.

Its virtue lies in its pure goodness: just berries, sugar, and lemon juice. In correct proportions, and with just the right amount of simmer time on the burner, this concoction works with the natural pectin within the fruit to create a lovely soft gel that I particularly love.

Meanwhile, back to the canning kettle and a few things to keep in mind:

Fruit selection: When picking out berries, looks can be deceiving, so always request a taste of the fruit before buying. For jam making, berries don’t have to be extremely sweet (a little tang will be countered by the sugar you add), but they must have a full and rich berry flavor.

For the strawberry jam with added pectin, make sure that all of your strawberries are ripe. Unripened berries contain a higher amount of natural pectin, which might make your finished jam too firm.

On the other hand, in Jan’s exquisite strawberry jam, since you won’t be adding commercial pectin, it’s a good idea to use a few under-ripe berries to make sure the jam gels.

Measure carefully: Don’t reduce the amount of sugar or lemon juice; both are necessary to guarantee a proper gel.

Check: Find the “Best if used by” date on the box of pectin. No sense handicapping yourself with marginal pectin.

Follow the recipe: exactly as written. Don’t skip a step or reverse the order of the steps. For instance, commercial pectin comes in two basic styles, liquid and powdered. When using liquid pectin, the fruit, sugar, and lemon juice (if called for) are combined and brought to a boil BEFORE stirring in the pouch of pectin, at which point the entire mixture is boiled for exactly 1 minute. On the other hand, if you use a recipe calling for powdered pectin, the pectin is combined with the fruit and lemon juice (if called for) then brought to a boil BEFORE the sugar is added and boiled for an additional length of time.

Oregon strawberry jam, with added pectin

Approximately 2 quarts of whole strawberries

7cups granulated sugar

1teaspoon butter (optional; it helps keep the foaming down during cooking)

1(3 ounce) pouch of liquid pectin (a common brand is Ball’s Fruit Jell Liquid Pectin)

Preapare jars and lids: If you’re going to make your jams “shelf stable,” as opposed to storing them in the refrigerator, you will need to process the filled-and-closed jars in a boiling water canner. This is the time to fill the canner with water and get it heating up on a back burner while you make the jam. I’ll walk you through the “processing your jars in a boiling water canner” further down in the recipe.

Start with freshly-washed canning jars and two-piece canning lids (available this time of year in most supermarkets and hardware-type stores). Wash them by hand in hot, soapy water, then give them a rinse and place the jars, bottoms up, on a towel-lined cookie sheet in a warm oven until needed.

To prepare the lids, just follow the manufacturers directions that came with them. Typically, you’ll place them in a pot of water which you’ll bring JUST to a boil then remove from the heat. The hot water softens up the sealing compound that is on the flat lids. Leave the lids in the hot water until you use them.

Proceed with making the jam: Wash and remove caps from strawberries. Place small batches in a bowl and crush one layer at a time until you have 4 cups of crushed berries. Place the measured berries in a 6- or 8-quart heavy-bottomed pot. Add the sugar, stirring to dissolve the sugar. Bring this mixture to a boil over high heat, stirring constantly. Add the butter, and stir it in.

Remove the pot from the burner. Add the entire contents of liquid pectin and quickly stir it into the hot fruit and sugar mixture. Return the pot to the burner, bring to a rolling boil (“rolling boil” means a vigorous boil that can’t be stirred back down to a simmer), and boil hard for 1 minute, stirring constantly.

Remove the pot from the heat and place it on a hot pad to settle down for a couple of minutes. At this point, if there is any foam on the surface, scrape it off with a spoon.

Filling and capping your jars:

Remove a hot jar from the oven and place it next to the pot of hot jam. Place the jar funnel on top of the jar and ladle some hot jam into the jar. Fill the jar to within 1/4 inch of the top. The space left between the surface of the jam and the top of the jar is called the “head space.” Lift off the funnel and place it on a clean surface, like a saucer or dinner plate. To make sure there are no droplets of jam on the jar rim, wipe it with a clean, damp cloth.

“Attach lid.” This phrase will be used in all future recipes. Here are the steps it involves: Using your magnetic lid wand, fish out one of the flat metal discs from the pot of hot water. Shake off excess water, and place it on the jar rim with the sealing-compound side down against the jar rim. Next, remove one of the metal screw bands, shake of excess water and screw it down onto the jar. Screw firmly, but not excessively. If you’re planning to process your jars in a boiling water canner (see below), then place your filled and closed jar in the pot of hot water using a jar lifter. Repeat the filling and closing with all of the jars, placing each one in the pot as it is filled and closed. You will probably run out of jam before you run out of jars.

Process in a boiling water canner (or not):

If you have enough refrigerator space, you can, at this point, simply store your jams in the refrigerator without further ado. They will hold their quality well beyond one year. But if you want to make your jams “shelf stable,” so they can be stored at room temperature without molding or otherwise suffering in quality, you need to process the jars in a boiling water canner. In some cookbooks, this procedure is called a “boiling water bath.” Use a pot that is deep enough to ensure that the jars are covered by at least 2 inches of water, and that there will be 2 inches of pan left to keep the boiling water from bouncing out while it’s boiling.

When the jars are filled, lids screwed on, and placed in the boiling water canner, bring the water to a boil. You may have to adjust the heat slightly at this point to tame the boil – you don’t want water leaping out of the pan, but you do want a vigorous boil that won’t go away. Boil the jars in the water (this is called “processing”) for 10 minutes.

Note: The processing time varies from recipe to recipe, although most jams are processed for 10 minutes. After the jars have been processed, remove them with your jar lifter and place them on a towel in a draft-free area of the kitchen.

Listen for the ping: The most satisfying sound to a food preservers ear is the tell-tale “ping, signifying that a vacuum has been formed and the jar is sealing properly. The ping occurs as the lid is sucked down from its convex to concave position. It occurs anywhere between the first few moments after removing the jars from the canner up to an hour or so. After the jars have completely cooled, check the seal by pressing down on each lid. If it’s truly sealed, the surface will be solid and won’t bounce back to your touch. Place unsealed jars in the refrigerator.

Makes about 8 half-pint jars of jam.

For food preservers with a little bit of canning experience, or adventurous beginners, I’m including my favorite strawberry jam recipe. One that is free of commercial pectin.

It’s based on my popular recipe for peerless red raspberry preserves, which is a fast-cook procedure. The resulting preserves are what I would describe as a “soft” gel. But it’s a luscious preserve, no commercial pectin giving the jam an unnatural firmness, and full of fresh Oregon strawberry flavor. All that and only about 7 minutes of cooking.

The secret to perfection is the brief, fast cooking in small batches (this recipe cannot be doubled). A wide, shallow pan (a 12-inch cast-iron skillet is perfect) is essential.

Jan’s exquisite strawberry jam

4heaping cups washed and hulled strawberries (1 pound, 6 ounces; to ensure a high pectin content, about 1/4 of the berries should be slightly under-ripe)

31/2cups sugar

1/3cup strained fresh lemon juice

1teaspoon butter

Coarsely chop the berries by placing small batches of them into the workbowl of a food processor and hitting the “pulse” button several times (you can also do this by hand, of course, but it goes pretty slow). You should have 31/2 cups of coarsely chopped berries.

In a large bowl, combine the berries with the sugar and lemon juice. Gently stir the mixture using a rubber spatula until the sugar is evenly distributed and the juices have begun to flow; let the mixture stand, stirring gently every 20 minutes or so, for at least 1 hour, but no longer than 2 hours.

Wash 4 half-pint jars. Keep hot until needed. Prepare lids as manufacturer directs.

Scrape the mixture into a 12-inch skillet or saute pan. Add the 1 teaspoon of butter (this controls the production of foam). Bring mixture to a boil over medium high heat, stirring constantly with a straight-ended wooden or nylon spatula. Adjust the heat downward to keep it from boiling over, and boil for 7 minutes. Remove from heat.

Remove the skillet from the burner and let the jam settle for about 20 seconds; if any foam remains, skim it off. Ladle hot preserves into 1 hot jar at a time, leaving 1/4-inch head space. Wipe jar rim with a clean, damp cloth. Attach lid. Fill and close remaining jars.

At this point, the jam may be stored in the refrigerator for up to six months or longer without the quality suffering.

For long-term storage at room temperature, you will need to process the jars in a boiling-water canner for 10 minutes (at 1,000 to 3,000 feet, process for 15 minutes; 3,000 to 6,000 feet, for 20 minutes; above 6,000 feet, for 25 minutes). Using a jar lifter, remove the processed jars from the boiling water and let cool on the counter, undisturbed, overnight.

Note about the consistency of the jam: This is going to be a very “loose” jam – the kind that moves around in the jar slightly as its tilted. So if you don’t like such a soft gel, you might as well steer clear of this recipe. There’s also a stronger likelihood of fruit wanting to float toward the top of the jar, which creates a clear layer of jam at the bottom of the jar. Here’s how I’ve managed to repair that phenomenon when it appears to be happening: About 3 hours after the jars have been removed from the boiling water canner, if you notice that that clear space at the bottom of the jars hasn’t started to fill in with fruit, then you can begin a cycle of turning the jars on their heads for periods of 60 minutes at a time (gently flip the jars for 60 minutes, then gently flip them back onto their bottoms for 60 minutes; repeat several times during the day or night). This really does seem to work.

Makes 4 half-pints.

Jan Roberts-Dominguez is a Corvallis, Ore., food writer, cookbook author and artist. Readers can contact her by e-mail at janrd@proaxis.com

Jan’s bare-minimum equipment list for making jam

Most of these items are self-explanatory and will be found in any department store where canning supplies are sold.

Boiling water canner: If you plan to store all of your preserves in the refrigerator, you won’t use this. But if you have limited refrigerator space, you’ll want to take the extra steps to “can” your batches of jam, fruits, pickles and relishes so that they can be stored at room temperature. This requires “processing” the filled and capped jars in a boiling water canner. They’re not expensive, and they’re usually made from lightweight aluminum or enameled metal. Any pot will do, as long as it will hold several jars sitting on a rack (see below), and still have enough head room to cover the jars with at least 2 inches of water boiling vigorously and not leaping out of the pot.

Canning jars and lids: The most common sized jars available are half-pints, pints, and quarts. You’ll need half-pints and pints for jams, relishes and chutneys, whereas the quarts are handy for bulkier items like pickles and fruits in syrup.

All sizes come in either regular or wide-mouthed tops. Obviously, wide-mouthed jars are easier to fill, however, from an aesthetic point of view, I tend to use more of the regular jars.

Jar funnel: Even if you’re using the wide-mouthed jars, you’ll need this device for filling canning jars. It’s designed to nest on top of an empty jar and direct a ladle-full of preserves (or relish, or salsa, or chutney, or pickles) down into it without leaving messy glops on the jar rim. Get one, they’re cheap!

Jar lifter: Unless your hands are tough enough to withstand a plunge into scalding-hot water, you’ll need this device to retrieve filled and sealed jars from the depths of a boiling water canner.

Lid lifter: A magnet embedded into the business end of a plastic wand, designed to fish out the lids from their hot soaking water. Look, ma! No hands.

Rack: This keeps jars off the bottom of the boiling water canner during processing. It also keeps jars from bumping into each other during the process, which helps to eliminate breakage.