Aperol is an Italian apéritif liqueur made with rhubarb, gentian, bitter orange, and other herbs and spices. It is bright orange in color and has a bittersweet flavor with notes of citrus, orange, and vanilla. Aperol is typically served with prosecco and club soda, but it can also be used in a variety of other cocktails, such as the Aperol Spritz, the Negroni, and the Americano.