Why This Recipe Works

Strawberry jam is a universal favorite. But the strawberries, which are naturally low in pectin, are often cooked too long, causing the fruit to lose its bright flavor. We shortened the cooking time in our recipe by cutting the strawberries into smaller pieces and then mashing them to release their juices and jump-start the cooking process. Shredded apple added natural pectin and fresh flavor to the mix. Lemon juice contributed acidity to balance the sugar’s sweetness and helped the natural pectin gel. Small, fragrant berries produce the best jam.

Before You Begin

Be sure to choose small, fragrant berries that are just ripe, and discard any that are bruised or mushy. Do not try to make a double batch of this jam in a large pot; rather, make two single batches in separate pots. Shred the apple on the large holes of a box grater.

Instructions

Place 2 small plates in freezer to chill. Using potato masher, crush strawberries in Dutch oven until fruit is mostly broken down. Stir in sugar, apple, and lemon juice.

Bring to boil over medium high heat, stirring to ensure sugar is completely dissolved. Continue to boil mixture, stirring and adjusting heat as needed, until thickened and registering 217 to 220 degrees, 20 to 25 minutes. (Jam is very frothy in beginning and requires near-constant stirring to prevent it from boiling over; froth will subside as jam boils.) Remove pot from heat.

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 jam is runny, return pot to heat and simmer for 1 to 3 minutes longer before retesting. Skim any foam from surface of jam using spoon.

Let jam cool completely, about 2 hours. Transfer jam to airtight container and refrigerate until set, 12 to 24 hours. (Jam can be refrigerated for up to 2 months.)