Why the Final Glass of Wine Often Tastes the Best

For many wine enthusiasts, the last glass of wine from a bottle often tastes the best, an observation that intertwines the art of winemaking with the subtleties of human perception. This phenomenon is not just a matter of personal bias or a psychological trick; it has a firm grounding in the science of wine evolution from the moment the bottle is opened until the last drop is poured.

Bottles: A Dual Role in Wine Preservation

A wine bottle serves two primary functions: it stores the wine and isolates it from external air. Oxygen, a critical element in air, is one of the greatest adversaries of wine. When wine and oxygen interact, an oxidation process begins, gradually deteriorating the wine over time. This isolation can also mean that, initially, the wine might hide some of its best characteristics, notably a reduction or even a loss of aromas and flavors. This is particularly true for bottles sealed with cork, synthetic stoppers, screw caps, glass closures, and other types.

The Paradox of Aeration

Understanding the sometimes negative effect of a bottle on wine leads us to the counterintuitive practice of aeration. While continuous air exposure can ruin wine in a bottle, once opened, it does not deteriorate unless left for an extended period. Contact with air, rich in oxygen, can invigorate the wine's characteristics, allowing enjoyment without waiting for the last glass. Oxygenation benefits mostly red wines, though the following principles apply to all types.

Simple Yet Ineffective Methods

The most straightforward method to aerate wine is opening the bottle well before consumption. This practice, common even in hospitality, often comes with the advice to wait about half an hour before serving. Unfortunately, this technique is minimally effective since the wine only contacts air through the small surface area at the bottle's neck. However, if using this method, pouring a glass or two after opening improves the wine's contact with air, both in the glass and remaining in the bottle.

Decanting and Carafing: Traditional and Efficient Practices

In restaurants, it's not uncommon to see wine transferred from a bottle to a larger glass container, known as a decanter. This process, called decanting or carafing, is used either to separate wine from its sediments or to accelerate aeration. Decanting applies to older wines with sediments that can diminish enjoyment. Carafing applies to other wines, where the wine is poured quickly into the decanter, enhancing its contact with air. Decanters, with their varied shapes, always offer a larger surface area for air contact than a bottle. Carafing produces rapid and effective improvements in everyday wines. To witness this, try tasting a glass before and after aerating the rest.

Using Aireators

Wine aireators are tools designed to enhance contact between wine and air. These devices, which can be attached to the bottle or held over a glass, use narrow channels or similar systems to mix wine with air as it is poured. The main advantage of aireators is their ability to quickly aerate wine, even when serving a single glass. However, their drawbacks include cost and potential awkwardness in handling, especially those used directly over the glass.

Considerations for Aeration

Not all wines require aeration. Generally, young, robust, and tannic red wines are the best candidates. More delicate wines need less aeration. Complex and aged wines don't need as much aeration as younger ones, but letting them breathe in a larger vessel can reveal deeper complexities. Very old wines should be decanted gently to remove sediments, with minimal aeration, and consumed promptly, as they are more fragile and can deteriorate if their evolution is rushed.

The phenomenon of the last glass tasting the best is a blend of scientific evolution and sensory perception. The art of winemaking and serving is about understanding and manipulating these factors to enhance the wine-drinking experience, from the first sip to the last.