Aging Wine In Oak Barrels

Winemaking is a labor-intensive art. Vintners spend years learning how to combine specific grapes to produce their classic vintages. In fact, each successive bottling has its own unique taste and texture and the older the wine, the better it taste. Wine is probably the only food that tastes better as it ages and the more it ages, the better it tastes. If the bottle is unopened, a singular vintage can literally last for centuries percolating in its own juices. However, some vintages can be drunk almost immediately as they are bred specifically for this reason.

Aging wine in oak barrels: How does this work?
Grape juice contains a unique mixture of pigments, phenols, sugars and yeasts that are mix together and combine over time to create a unique taste, flavor and fragrance. When the wine is young and has just been made, it tends to have the youngest and sharpest of tastes but these flavors mix and settle down leading to mild tones but excellent bouquets. However, the opposite can also happen as great wines that have been allowed to mature can result in an over-amount of tannins and acids that create a harsh bitter taste in the wine.

According to the French, wine draws its essences from air, soil, sunshine, water and the atmosphere in which it is stored. The French refer to this as ‘terroir’. The acids and sugars present in the wine are derived from the environment and they are naturally tinted with materials present in these environments. These two ingredients mix together to make alcohol and glycerol that add depth and flavor to the wine. Another important ingredient for developing wine flavoring is tannin. Tannin by itself is very astringent in taste but it is very prominent in young wines. As the wine ages, the tannin in the wine settles down to the bottom of the bottle. This also reduces the astringent taste of the wine and turns it mellow and subtle in taste.
The French were also the first to actively evaluate the process of corking and storing wine to prevent it from going sour due to vinegar formation. During the early to mid-1800s, the French noticed that newly bottled wine bottles were going sour quickly. Even prominent French scientist Louis Pasteur called in by 1863 as the French were getting seriously worried about their wine going sour. He quickly noticed that too much oxygen in the bottle was the primary reason for the souring. According to his theory, bottled wine already had enough oxygen in the liquid to keep the bacterial alive for a very long time. It was completely ok to seal the bottle and leave it be to mature in silence. This also contributed to wines maturing in taste and flavor.

The oxygen content inside wine is primarily because of fermentation. Wine starts fermenting as soon as it reaches the fermentation barrels and it draws its oxygen through the wooden staves of the wood barrel. As a result, vintners and vineyard owners are very careful about barrel selection, the staves, wood and thickness of the wood used in the barrels. Oak wood is preferred as it is the most aromatic wood with extra tannins and phenols. However, any variety of wood can be used to make the barrels. A point to note is that the more porous the wood, the better the wine taste. Most barrels makers prefer wood from the Limousin forest in France but American oaks from the California Coast or German oaks from the Baltic area are good as well. Sometimes the staves are impregnated with tartrate crystals that change the taste of the wine eventually.
Will these influence wine taste and fragrance?
Barrel location, surroundings, sound, wind, sun; in fact everything in the surrounding area will influence the taste, color and fragrance of a wine.  If wine is left too long, the flavor falls flat with no color and fruity flavors but too little time and the wine tastes acidic, bitter or yeasty. Most wines that are barrel aged tend to last longer as they are aged more as well. Some bottlers prefer to age the wine in glass bottles and this aging process is a little different. In bottle aging, the wine loses air to the bottle and this creates a process called reductive aging. Tannins in the wine are preserved and new compounds are formed causing a deeper color. The tannins stabilize in the wine losing bitterness and form milder compounds.
In the end

The younger the wine, the more fresh and fruity it is and the more it is fermented, the deeper the color and taste. Most dark red wines are drunk within 5 years of bottling but some need to be kept longer.