The crusta is a drink template that goes as far back as the original cocktail template of spirits, sugar and bitters. Crustas expanded on that formula with lemon juice, making it the earliest form of the sour, and the eldest ancestor of popular drinks like the sidecar. Since its one of those ancestral drink templates, its seen a lot of updates and substitutions. Most recipes call for brandy or cognac, but it does well with bourbon or rye. Its fabulous with triple sec, orange curaao, or any other not-too-sweet orange liqueur. Later renditions of the recipe called for maraschino liqueur, which we now see as a critical component of the modern crusta. The oldest recipes call for a sugared rim and a large piece of lemon peel. We find the full-on sugared rim to be too messy and fussy, so we just do it on half the rim and let the drinker choose which side to sip from.