It's not very difficult to reverse-engineer most cocktails that have 3-4 ingredients in them, especially if any of the ingredients are visible as a garnish (e.g

It's not very difficult to reverse-engineer most cocktails that have 3-4 ingredients in them, especially if any of the ingredients are visible as a garnish (e.g. herbs, citrus slices). And even then, an inquisitive patron would be able to get the ingredient list by asking questions and/or claiming to have allergies. It would be strange and potentially dangerous for the bartender to without knowledge of the ingredients. The bottom line is that anyone who really wants to steal a cocktail recipe is going to be able to.