Just Right Strawberry Preserves 3.500

Deb Lindsey for The Washington Post

Canning Canning Class Jun 11, 2014

Fruit forward, jewel-toned and with a sure set, this jam captures the charms of in-season strawberries. A green apple is the secret ingredient that will add much-needed pectin, with little change in flavor or texture.

Make sure to use about three-quarters perfectly ripe berries and the rest under-ripe; the latter have more natural pectin, further contributing to a proper set.

You will need a candy thermometer. You'll need 4 sanitized half-pint jars with new lids and rings; see the NOTES, below. If you plan to do lots of canning, you might want to invest in a preserving pan, which is recommended for this recipe. It's wider at the top and often has handles on either side for heavy lifting.

Make Ahead: The uncooked apple-strawberry mash needs to rest in the refrigerator for 2 to 24 hours. Store the preserves in a cool, dark place for up to 1 year. Refrigerate after opening.

3.5 - 4 half-pint jars

When you scale a recipe, keep in mind that cooking times and temperatures, pan sizes and seasonings may be affected, so adjust accordingly. Also, amounts listed in the directions will not reflect the changes made to ingredient amounts.

Tested size: 3.5-4 half-pint jars

  • 3 pounds (about 2 quarts) strawberries, hulled
  • 3 cups granulated sugar (organic or raw may be substituted, but use weight, not volume; 26.4 ounces)
  • Juice of 1 lemon
  • 1 Granny Smith apple
  • 1/2 teaspoon unsalted butter (optional)

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Combine the strawberries, sugar and lemon juice in a large mixing bowl; use a potato masher or broad, nonflexible spoon to mash the fruit into the sugar just enough so that some larger pieces of berry remain.

Use the large-holed side of a box grater to grate the (unpeeled) apple directly into the bowl, turning it once the core is exposed. Stir to incorporate thoroughly. Cover and refrigerate for 2 to 24 hours.

Pour the mixture into a colander set over a heavy-bottomed 5-quart preserving pan or pot. Stir, encouraging the collected syrup to fall into the pan or pot. Remove the colander, seating it inside the bowl to capture any remaining syrup; add that to the pan or pot as needed. Leave the solids in the colander while you cook the syrup.

Clip the candy thermometer onto the preserving pan or pot; cook over high heat to bring the syrup to 220 degrees, the soft-ball stage in candymaking. The syrup will foam and rise up, so stir it from time to time. Add the berry mixture to the syrup, stirring as the preserves return to a rolling boil. The preserves will foam and rise up as the water boils away and the set is achieved. Stir constantly until the foam is nearly gone, at which point, the jam will be done. Turn off the heat and test the set (see NOTES, below).

Once the set has been achieved, add the butter, if desired. Stir well and thoroughly without scraping the sides of bottom of the pan or pot until the last bits of foam have disappeared.

Ladle the preserves into the sanitized jars, leaving 1/2 inch of head space. Run a chopstick or flat plastic knife along the inside of the jars to dislodge any air bubbles. Clean the rim of each jar, place the warmed lids and finger tighten the rings (not too tightly). Process in the boiling water bath for 10 minutes (see NOTES, below). Turn off the heat and use the jar lifter to transfer the jars to a clean, folded dish towel to cool for several hours.

Label and date the sealed jars. Store in a cool, dark place for up to 1 year. Refrigerate after opening.

NOTES: There are three ways to test the set. The sheeting test entails stirring the preserves, then lifting the spoon to watch the jam sheet off the spoon, flowing slowly and collecting along the bottom of the spoon before languidly dripping back into the pot. It should look like jam, not like syrup. The sheeting test takes a practiced eye.

The cold plate test is a surefire method of testing the set. Before beginning to cook the jam, tuck 3 small plates and three spoons into the freezer. Once the preserves seem to be set, use a cold spoon to place a tablespoon or so of jam on the plate. It should set instantly. Press against the blob of jam. Does it resist just a bit? Wrinkle a little? It’s done.

The third method is the lazy cook’s cold plate test. Remove the preserves from the heat and cool for 3 to 5 minutes. Press against the surface of the jam. Does it resist just a bit? Wrinkle a little, as though a very small pebble has hit the surface of a pond? The jam is ready.

For jam that is not yet set, return the preserves to the stove; cook for 2 to 5 minutes at a strong, hard, foamy boil that rises up no matter how much you stir; then test again. Stop and start the cooking process as many times as necessary until you are satisfied with the set. The jam will set further as it sits, so err on the side of a loose set vs. a very firm set.

Water-bath canning safely seals high-acid, low-pH foods in jars. The time for processing in the water bath is calculated based on the size of the jar and the consistency and density of the food. For safety's sake, do not alter the jar size, ingredients, ratios or processing time in any canning recipe. If moved to change any of those factors, simply put the prepared food in the refrigerator and eat within a week.

Fill a large canning kettle or deep stockpot two-thirds full with water. To keep the jars from rattling against the pot, place a rack in the pot. (A cake rack works well; a folded dish towel is equally effective.) Sanitize the jars in a short dishwasher cycle or by boiling them in a canning kettle or pot for 10 minutes. Fill a small saucepan with water and add the rings. Bring to a boil over high heat, slip in the lids and turn off the heat.

Use a jar lifter or tongs to lower the filled, sealed jars into the boiling water bath, keeping them upright. When all of the jars are in place, the water should be 1 to 2 inches above the jar tops. Add water as needed. Bring the water to a low boil before starting the timer for processing.

At the end of processing, turn off the heat and let the jars sit in the water bath until the boiling has stopped. That will reduce siphoning, in which the food burbles up under the lid, breaking the seal. Use the jar lifter or tongs to transfer the jars to a folded towel, keeping them upright. Leave the jars until they have completely cooled, at least 12 hours. Remove the rings and test the seal by lifting each jar by the lid. The lid should hold fast. Label and store in a cool, dry, dark space.

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Recipe Source

From Cathy Barrow, author of "Mrs. Wheelbarrow’s Practical Pantry: Recipes and Techniques for Year-Round Preserving" (Norton, November 2014).

Tested by Cathy Barrow.

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