Optional step: For a smooth consistency, strain the mixture through a fine mesh colander into a bowl. Mash the blueberries with the back of a large spoon in order to extract as much liquid as possible, then discard the mashed blueberries.
Pick through your blueberries and discard any bad berries, stems or debris. In a medium saucepan, combine the blueberries, honey, ½ teaspoon lemon zest, 2 tablespoons lemon juice and salt. Bring the mixture to a simmer over medium heat. Reduce the heat to a gentle simmer, then cook, stirring occasionally, for 15 minutes.