This mocktail is a great way to cool down on a hot day or evening. It's simple to make and delicious. If you want a pitcher instead of a glass, just multiply the ingredients accordingly.
If using lemon zest and sugar, rub the sugar with the zest.
Add the 3 ingredients (sugar, water and lemon juice) together in a small pot. Heat it to boiling, stirring occasionally until the sugar is completely dissolved.
Cool the simple syrup down, strain it to remove the zest, and refrigerate it. This recipe makes more than you'll need for a single serving of the mocktail - it's useful for other drinks or for making more mocktail.
Mix the sparkling water, ice, bitters, and cooled simple syrup together in a glass. Stir. Slightly crush a few mint leaves (to release their flavor) and add them to the mocktail.
Strain the crushed mint out and garnish the drink with a lemon slice and the rest of the sprig of mint.
Make the lemon simple syrup ahead of time, so it can cool down before you add it to the mocktail.
If using a sugar substitute that is liquid, I've seen a number of sources that suggest infusing the liquid with the zest for a few hours. That sounds right, but I personally haven't tried it.
To crush the ice, you can use either a manual ice crusher or a high speed blender. My Vitamix did just fine. If you don't have either piece of equipment, use chips of ice or even small, whole cubes. I like how the crushed ice works dissolves a bit as the drink sits, but that aspect of the mocktail is not crucial.