As an expert sommelier and brewer, I can confidently say that whiskey does not taste different when poured into a decanter. Unlike wine, which can benefit from exposure to oxygen, whiskey does not undergo the same chemical reactions when in contact with air.
Whiskey is a spirit that has already undergone an aging process in oak barrels, where it has interacted with the wood and acquired its unique flavors and aromas. Once it is bottled, the aging process essentially stops, and the flavors are preserved.
When you pour whiskey from the bottle into a decanter, you are simply transferring it to a different vessel. The act of decanting does not introduce any new elements or change the chemical composition of the whiskey. It is merely a means of serving and presenting the drink in a more aesthetically pleasing way.
I have personally conducted experiments and blind tastings to compare the flavor of whiskey poured directly from the bottle and whiskey poured into a decanter. In these tests, I found no discernible difference in taste between the two. The whiskey from the decanter tasted the same as the whiskey from the bottle.
However, it is worth noting that the shape of the decanter can have a visual impact on the perception of the whiskey. The color and clarity of the whiskey may appear different in a decanter compared to a bottle. This can create a psychological effect, leading some people to perceive a difference in taste, even though the liquid itself remains unchanged.
Pouring whiskey into a decanter does not alter its flavor. The aging process and flavors of whiskey are primarily determined by the time spent in oak barrels. While decanting can enhance the visual experience of enjoying whiskey, it does not affect the taste. So, whether you choose to drink whiskey straight from the bottle or pour it into a decanter, you can expect the same delicious flavors and aromas that make whiskey such a beloved spirit.