This recipe was my paternal grandmother’s staple refresher during hot summers in Toronto. We rarely visited because it was so far, but this was in our hands not long after we arrived. She was a talented cook but always kept it simple and straightforward, like this drink. I helped her make a batch once, and wondered at all the chemistry of it. The syrup bottles and keeps beautifully through fall as well. The drink is bright and thirst-quenching and can be made with any varieties of citrus you prefer. It works work well over shaved ice too.