Rinse the strawberries, dry them thoroughly, remove the hulls, and slice the berries. Place the strawberries, sugar, water, and optional lemon juice in a saucepan.

Bring the mixture to a gentle boil over medium heat, stirring until the sugar dissolves. Reduce the heat and simmer uncovered for 10 to 15 minutes, stirring occasionally and lightly mashing the berries.

When the strawberries are soft and have released their juices, remove the saucepan from the heat. Stir in the vanilla extract if using.

Pour the warm mixture through a fine-mesh strainer into a clean bowl or jar. Press gently on the fruit for additional liquid, then cool the syrup before refrigerating.