Step 1

Bring blueberries, lemon zest, lemon juice, and maple syrup to a simmer in a medium saucepan over medium heat and cook, stirring occasionally, just until blueberries begin to burst, about 5 minutes. Use a spoon to lightly mash about half of the berries to release their juices. Increase heat to medium-high and bring to a boil. Cook, stirring occasionally, until juices are reduced by half, 5–10 minutes.

Step 2

Remove jam from heat; taste and add a bit more maple syrup if you prefer it to be sweeter. Return to a boil, then stir in chia seeds; cook 1 minute to soften seeds. Let jam cool slightly, then transfer to heatproof jars or containers. Cover and let cool completely. Chill until ready to use.

Step 3

Do Ahead: Jam can be made 2 weeks ahead. Cover and chill, or freeze up to 2 months.