Why Wine Is Aged In Oak

After fermentation is completed and wine is racked several times to remove the largest solids, the young wine is usually rough, raw and “green” and needs to settle for a period of time. This aging can be done in neutral containers such as stainless steel, cement lined vats, old large casks, etc. or it can be done in small relatively new wood barrels which are not neutral, but which will influence the developing wine.

The oak wine barrel is one of the most recognizable symbols associated with wine. We have romanticized the barrel and the act of aging wine inside of it to such a degree, that after the barrels have been used for their intended purpose we often turn them into tables, benches, planters and even candle holders. Yet the reason we began aging wine in oak barrels in the first place was not intentional, but the result of a happy accident. For millennia, the clay amphora was the storage medium of choice for transporting wine.

Subtle flavors are imparted to wine as it ages in the barrel. Different types of oakfrom different regions give differing levels of flavor to the wine. As it rests in the barrel, goes through subtle chemical changes, resulting in greater complexity and a softening of the harsh tannins and flavors present at the end of fermentation. The effect of specific wood on different wines is the subject of great discussion and experimentation among wine makers throughout the world.
A barrel essentially does two things: it allows a very slow introduction of oxygen into the
wine; and it imparts the character of the wood into the wine. (This diminishes as a barrel
gets older. You usually get 50% of the extract that a barrel has on the first
use, 25% the second and less after that.)