Triple Sec is the French liqueur in which dried sweet Valencia and bitter Curaçao orange peels are soaked in alcohol, after which it is distilled. Cointreau is most known Triple Sec.
Sometimes, very occasionally, the drink is also aged in barrels. And we scored one! We got casks from the Lions of Cyprus distillery and matured an imperial stout on them. This produces a surprising combination of the roasted chocolate notes of the stout and the fresh notes of the orange liqueur.