I decided I'd try my hand at making my own. I adapted a recipe from Food52 and I love it!! I made single serving, then a small pitcher full and lastly, a concentrated version to freeze and add water later.
1 1/4 cup sugar
1 1/4 cup boiling water
3 cups quartered strawberries (about 16 oz.)
20 medium basil leaves, chopped
1 1/2 cup fresh lemon juice, 6-8 lemons
Juice the lemons until you get 1 1/2 cups, set aside.
Put the sugar in a heatproof bowl, pour the boiling water over the sugar and stir until combined, let cool.
Put 3 cups quartered strawberries into a blender/food processor, add the chopped basil and 1/4 cup of the sugar water. Blend until really smooth.
Combine equal parts strawberry puree, lemon juice and sugar water (1 1/2 cups each). This makes a concentrate. To this add 3.5-4 cups cold water. Serve with ice.
If make a single serving, put ice in a cup, add 3 T. each of strawberry puree, lemon juice and sugar water, add 1/2 cup cold water.
In the food52 recipe, they used 3:3:1or2 ratio. I thought it needed more sugar, so I upped it.
UPDATE: After sitting in the fridge overnight, it tasted much more sugary than after I just made it. I may try the actual food52 recipe next time.