In a sauce pan over medium heat, add all the ingredients. Bring just to a bubble and reduce heat to medium low. (If you using frozen berries, this might take a little longer)
Allow to simmer for about 10 minutes. Use the back of a spoon to press and pop the blueberries while they simmer.
Remove from heat and pass syrup through a fine mesh sieve. Again, use the back of a spoon to press and pop all liquid through the mesh, leaving just the skins behind.
Pour syrup into jar and let cool on counter for about an hour. Use right away or secure lid and store in refrigerator up to 2 weeks.