The alcohol in a liqueur comes from distilled spirits like vodka, brandy, rum, or whiskey. These spirits serve as the foundation, which is then infused with flavors such as fruits, nuts, herbs, or spices. Sugar or sweeteners are added to create a rich, balanced taste. Liqueurs generally have lower alcohol content than spirits alone, offering drinkers a smoother option that blends easily into cocktails or after-dinner sipping.