
Coffee liqueur is a sweetened spirit infused with roasted coffee, ranging from dark, syrupy styles to lighter, more bitter ones.
Coffee and sugar together, and the sugar is what varies wildly across the shelf — from heavily sweetened to nearly dry. Taste before you build, because a recipe balanced on one bottle needs its syrup rewritten for another.
Dry coffee liqueur
Much less sugar and more roast, made for drinks in which the coffee leads; swapping it for a sweet bottle by volume leaves the drink sour and thin.
Coffee-flavored vodka and spirits
No sugar in them, and often no real coffee either. They color and flavor a drink and cannot sweeten it, so an Espresso Martini made on one comes out thin and needs syrup added back.
Sugar preserves as surely as alcohol, so an opened bottle keeps for years and what it loses is aroma, quietly. In the cold, sugar can crystallize at the bottom: gentle warmth and a shake put it back into solution. Keep it out of direct sun, which takes the color and the scent together.