Our sense of smell accounts for about 80% of what we taste. Coopers' Craft master distiller Chris Morris says by nosing the glass, we can perceive more complexity in the bourbon.
Morris adds that nosing the spirit eliminates "the impact of alcohol that results from tasting", which could cover up the bourbon's aromas and make you miss out on all its notes.
Some of the other steps to experiencing bourbon include the Kentucky chew (swishing the bourbon in your mouth) and paying attention to how the bourbon finishes on your palate.