First, juice all your lemons. You can do this in advance and store it in the fridge for a day if you like.
Then, make a simple syrup on the stove with which to sweeten the lemonade. Heat 1 cup water and sugar on the stove over medium heat. Stir until sugar dissolves, then remove from heat and let cool slightly.
Meanwhile, prepare your blueberries. Wash them, then blend them with 1 cup water to make a purée.
With a fine mesh strainer or cheesecloth, strain out the seeds and pulp so you are left with a blueberry juice. You may need to repeat this one or two times to remove all seeds.
Combine the lemon juice, simple syrup and blueberry juice in a pitcher. Top with remaining 4 cups cold water. Refrigerate until ready to drink!
Notes
Tips & Tricks
Use the juice from fresh lemons. When making lemonade, where lemon juice is the star, it makes a big difference in flavor.Be sure to use room-temperature citrus. Refrigerated lemons will not juice as well as ones that have been warmed up.You can microwave them briefly for about 10 seconds to get a to warm them up or just leave them out for an hour or two before you plan to juice them. Sweeten it to taste, add a little bit of syrup and add more as desired.