Why is Wine Aged in Oak Barrels?
Many of us are aware that most fine wines are aged in barrels made of oak. What is less well known is the reason for this. What are the advantages of oak? What, if any, are the disadvantages? Are there different varieties of oak barrel? Do these affect the wine differently? What are the differences? How does the whole process work?
Aging Wine before Bottling
Once the fermentation process is complete, wine is repeatedly racked to remove the larger solid particles. This young wine is ‘green’. It’s rough and raw and needs time to age in containers that are made of neutral materials. Stainless steel, old casks or cement vats are ideal for this. Alternatively, the wine can initially be aged in small wooded barrels. These are not neutral and will affect the wine as it ages.
Oak Aging Wine
As the wine ages in wooden barrels, subtle flavors from the oak slowly start to affect its development. French or American oak are commonly used. These are sourced from different regions (eg. Nevers, Limousin, Troncais) to impart slightly different flavors (described as ‘vanilla’). Small chemical changes start to work on the wine as it rests in the barrel. The result is a softening of the harsh tannins present during fermentation and a more complex flavor. The different effect of specific woods is a fascinating subject, much discussed by wine makers all over the world. The barrel serves two purposes for the aging wine: it allows oxygen to enter the wine very slowly over time and imparts some of the flavor, or character, of the wood into the wine.
What happens to destilates when are aged in a Oak Barrel?
The contact with wood makes alcohol smoother, softer and even better tasting. Due to the lesser toasting of wood during the construction of barrel, wines develop additional scents. The barrel needs to be placed in a humid space where the temperature will change throughout the day. Expansion and contraction of the liquor is important to the aging process. The liquor needs to expand into the wood of the barrel. The liquid is capable of penetrating almost half way through the barrel’s edge. Then, when the temperatures cool off, the liquid retreats and brings with it a bunch of flavor that the barrel itself is responsible for.
People talk of tannins in wine. Tannins are especially evident in the taste of red wines and are believed to be from the skins and stems of the grape. If the wine has been aged in an oak barrel then some of the tannins have been drawn from the wood itself.
Another key part of the aging process is the infusion of wood sugars into the spirit. Wood sugars are especially evident from a charred oak barrel because the heating process draws these natural elements out of the wood and into the liquor. Wood sugars give the liquor a depth of flavor and a slight sweetness. Overall, oak barrel aging gives the liquid a vanilla, cinnamon, nutmeg, black pepper and butterscotch flavor.
It also makes the liquid a lot more smooth for a different mouth feel.
A new barrel is best for this and the effect diminishes sharply with repeated use.
The Key Benefits of Wood Summarized:
1- The micro-oxygenation that is the act of breathing which is the contact of the liquid with the air. This function is beneficial to the structure of the wine and ensures its longevity;
2- In contact with the wood the wine receives flavors and aromas, which can be accentuated or not depending on the process of toasting that each barrel suffers;
3 – Oak wood also has the property to soften and round the tannins of a wine, in other cases, to tame rebellious tannins that are characteristic of certain strains;
4- A part of the structure of the wines, also comes from the tannins that the oak provides, it is also important to intensify the color of the drink;
5- Red or white can present a wide range of natural colors and the barrel is also responsable for stabilizing its color.