No-Commitment Strawberry Jam

May 25, 2016
From the book Foolproof Preserving from America’s Test Kitchen
No-Commitment Strawberry Jam | WGBH | CRAVING BOSTON

The beauty of no-commitment jams lies in their simplicity. They generally make a small batch, which means you don’t need to invest in bushels of fruit, and there’s no need to process jars in boiling water for long-term storage; you can keep the two jars of jam the recipe makes in the fridge and finish them off in a few weeks. Also, a small batch of fruit will cook down quickly to the proper consistency, resulting in a vibrant and fresh-tasting jam. And because the cooking time is so short, there’s no danger that the naturally occurring pectin in the fruit won’t do its job (a risk when cooking larger batches). In addition to the pectin in the fruit itself, hefty doses of lemon juice and sugar help this jam set up perfectly. Crushing the strawberries with a potato masher before cooking jump-starts the release of pectin and further decreases the cooking time, ensuring maximum fresh fruit flavor. The jam will continue to thicken as it cools, so it’s best to err on the side of undercooking. Overcooked jam that is dark, thick, and smells of caramelized sugar cannot be saved.

1 1/2 pounds strawberries, hulled and cut into ½-inch pieces (5 cups)
1 cup sugar
3 tablespoons bottled lemon juice

Be sure to use bottled lemon juice, not fresh-squeezed juice, in this recipe or the jam might not set up properly. This jam cannot be processed for long-term storage.


1. Place 2 small plates in freezer to chill. In large saucepan, mash strawberries with potato masher until fruit is mostly broken down. Stir in sugar and lemon juice and bring to boil, stirring often, over medium-high heat.

2. Once sugar is completely dissolved, boil mixture, stirring and adjusting heat as needed, until thickened and registers 217 to 220 degrees, 15 to 20 minutes. (Temperature will be lower at higher elevations.) Remove pot from heat.

3. To test consistency, place 1 teaspoon jam on chilled plate and freeze for 2 minutes. Drag your finger through jam on plate; jam has correct consistency when your finger leaves distinct trail. If runny, return pot to heat and simmer for 1 to 3 minutes longer before retesting. Skim any foam from surface of jam using spoon.

4. Meanwhile, place two 1-cup jars in bowl and place under hot running water until heated through, 1 to 2 minutes; shake dry.

5. Using funnel and ladle, portion hot jam into hot jars. Let cool to room temperature, cover, and refrigerate until jam is set, 12 to 24 hours. (Jam can be refrigerated for up to 2 months.)