Simply, it tastes better, but it's much more than that. Everything from the nose, to how it opens up, to the palate, to the mouth feel, to the finish is affected. Do not be intimidated by the process or by how fancy some decanting carafes may look. Some are simple and are made for functionality. Others, I am certain, require an advanced degree in chemistry to understand how to use it. During the process of opening a wine bar, I have had the privilege to taste many wines from all over the world. There have been some tastings where I wish I had a decanter to help some of the younger wines. Many wines I have tasted are for our wine program but, a part of me, being a wine lover, wants to experience each wine at its fullest potential. Decanting will help a lower quality wine taste better. It helps a young bold wine develop. A chilled wine can get to the proper temperature before drinking. Decanting softens the tannins for any wine made using contact with the skins. Old wines benefit greatly from decanting but they don’t like being out too late (I understand this more the older I get.) Decanting will improve the experience with wine but here’s why.
Decanting separates the wine from the sediment in the bottle. Usually it's red wines that contain the most sediment. It is not harmful; however, it’s like drinking the grounds in your morning coffee. This can ruin the experience, unless you're into that kind of thing. Rose and white wines can benefit from decanting but this is most useful with older red wines. If an older wine is being drunk at its peak then all that is needed is to remove the sediment so that the flavor is not suppressed. The sediment in wine affects the texture, flavor and clarity. How a bottle is stored, horizontal or vertical, also affects how challenging the decanting process will be. Also, How a bottle is subjected to motion when it is pulled from the cellar. The goal is to keep the sediment in the bottle and not waste any juice.
Decanting also allows the wine to breathe. This is called aeration. In this process oxygen is introduced to the wine. Just like some good O2 enhances our body, it does the same for the wine; which is a living thing. The wine has been starved of oxygen which causes all the wonderful aromas, flavors, textures and tannins to develop in the bottle. The young wine needs the aeration because it is not fully developed. Ever notice a foul smell when immediately opening a bottle? There are compounds trapped in the bottle waiting to escape. Allowing the wine to rest and develop in the decanter for several minutes to an hour can change the aromas you sense. If oxygen interacts with the wine for an extended amount of time it can then suppress the amoral and flavors (too much of a good thing effect.) Aeration helps to bring out all the incredible flavors of the grapes and amazing craftsmanship of the winemaker.
So, try it! Decanting is easy and there are several methods and many gadgets that assist the process. Keep the process simple. Decanting does not have to be intimidating. Choose a decanter that serves your purpose for decanting, removing sediment, aeration or bringing to temp. Also, make sure it's beautiful, whatever that means to you. Decanting is meant to improve the wine and how we experience it with all our senses. Trust your palate. Taste the wine while it is resting. That is how you will know it has been decanted enough. The reward is an overall greater experience for you and your company. Have a wine tasting with friends where you try the wine straight from the bottle. Then taste it after it’s been decanted and note the differences. You will notice some aromas are stronger and others are muted. The texture has changed and the tannins become softer. Simply, it tastes better.
One other thing:
Decanting also helps to remove the cork out of the wine for when you break it opening that bottle full of fantastic juice. (Speaking from experience here.) Salud!