Add the sugar and water to a saucepan on the stove. Turn the heat to medium low.
Continuously stir and heat the sugar and water until sugar has dissolved (the mixture will be clear with a slightly golden tint). Turn off the heat, and set aside to cool (put it in the fridge if serving soon).
In a blender, combine blueberries and 15 oz (just shy of 2 cups) lemon juice. Zest one large lemon into the mixture. Juice your newly naked lemon into the blender.
Blend the mixture until it’s smooth and combined (about a minute).
Place a strainer over a large bowl, and pour the blueberry mixture through it. Use a spoon to stir the mixture around in the strainer and ensure all the lemony goodness makes it into the bowl.
Combine the blueberry-lemon juice mixture and the sugar water into a large pitcher and stir to combine. Garnish with fresh mint or basil, and enjoy!
Note: the mixture will likely still be slightly warm, if serving immediately be sure to use lots of ice.