Place a small plate in the freezer before you start cooking.

To a 1-quart or larger saucepan, add the strawberries, sugar, and lemon juice.

Use a potato masher or the bottom of a flat glass to lightly smash just a few of the strawberries.

Bring to a boil over medium-high heat while stirring frequently.

Turn the heat to the lowest you can to keep it at a full boil. Let boil for about 9 minutes.

When you think the preserves are ready, drop a small spoonful onto the cold plate and let it sit for a minute.

When it's done, stir in the vanilla extract.

Remove the saucepan to a wire rack to cool completely, about 1-2 hours.

Transfer into clean jars and refrigerate for up to 1 week.