Combine berries and maple syrup in a medium saucepan. While stirring, bring to a simmer over medium-high heat. Continue to simmer for 5-10 minutes, mashing the fruit with a fork or wooden spoon.
Reduce the heat and stir in the chia seeds. Cook over low heat for an additional 10-15 minutes, stirring occasionally until desired consistency is reached. Taste test and add additional sweetener if desired.
Cool and transfer to a container. Store in an air-tight container in the refrigerator for up to 2 weeks. The jam will continue to thicken as it cools.
