Honey Version: Replace sugar with 3 cups raw honey. The flavor will be darker and more complex, but the syrup won't keep as long—use within 1 month or freeze.
Mint Elderflower: Add 1 cup fresh mint leaves during the steeping stage (step 3) for a cooling summer flavor.
Orange Variation: Swap lemons for oranges (zest and juice) for a warmer, less sharp profile.
Freezing: This freezes beautifully in ice cube trays. Pop them out and store in bags for single-serving portions all winter.
Safety: Do not water-bath can this recipe. Without commercial citric acid, it's not acidic enough for shelf-stable storage. Refrigerator or freezer only.
To Use: Mix 2 tablespoons with sparkling water and ice. Pour warm over vanilla ice cream. Whisk into whipped cream. Add to gin and tonic. Stir into hot tea with a shot of bourbon on cold nights.