How to Make It
Stir together strawberries and sugar in a large saucepan. Cook over medium, stirring occasionally, until sugar dissolves. Stir in lemon juice. Increase heat to medium-high; let mixture come to a boil, stirring often. Continue boiling over medium-high, stirring often, 1 minute.
Reduce heat to medium. Attach a candy thermometer to saucepan; simmer mixture over medium, stirring often, until mixture reaches 220°F, about 30 minutes.
Immediately ladle jam into 2 (2-cup) sterilized canning jars. Cover jars with lids, and let cool completely at room temperature, about 2 hours. Store in refrigerator up to 2 months.