High-quality spirits should breathe. The best way to do this is in a long-stemmed brandy glass, also known as a nosing glass. The shape is crucial. The glass should be narrow at the top and have a bulbous curve at the bottom. The natural aromas collect at the bottom and are optimally channelled into the nose.
A narrow glass opening also ensures that the bouquet does not evaporate too quickly. A long stem also keeps the heat from your hands away from the drink.