Choose the substitute that matches your goal: closest melon aroma (melon liqueur or cantaloupe-infused vodka) or “closest sweetness” (schnapps + syrup).
Start with the table ratio (1:1 where possible). For higher-ABV or stronger syrup options, reduce by 10–25% first.
For drinks, taste after mixing: add a splash of juice or a small pinch of sugar to match the sweetness of the original.
For baking, account for extra water from fruit juices/syrups by reducing added liquid or sugar slightly.
Let it rest 5 minutes and re-taste—melon aromatics change as the mixture sits.