Oak barrels have long been in use for storing wine as these were the only containers that were deemed practical for storing liquids. Hence, this is why these containers are still being used by people today otherwise no one would have came up with the idea of adding new dimensions to the flavor of the wines via oak flavor coming from oak barrels. Wine, when stored in oak barrels, are extremely flavorful, have richer texture and its flavor is more complex whereas wine stored in a completely non-reactive container is not the same. Thus, it is a historical coincidence that oak wood and wine form a match made in heaven.
Have you ever wondered by only oak barrels are used for storing fine wine? Well, this is because oak is the only type of wood which is suitable for this purpose. Additionally, oak imparts a great taste to wine and enhances its flavor. There are two benefits of wine coming in contact with oak wood:
First of all, in case of red wine, oak barrels help in controlling or modifying the process of oxidation that takes place. This process takes place slowly, it increases the wine’s stability and color slowly while decreasing its astringency while turning the fruity flavor into a more complex one. The method used here involves topping the oak barrels with wine or filling them up to the brim; after this the wine is racked from one oak barrel to another in order to clarify it and to introduce just the right amount of oxygen into the wine for the latter’s benefit during the next couple of months.
Secondly, oak barrels contain many classes of complex compounds of chemicals, all of which impart their flavor and textural note to white wine as well as red wine. Out of these flavors the most common one would be the vanilla flavor, sweet aroma, toasty flavor, notes of tobacco, tea notes, complex flavor of tannin mixed with the flavor of fruit (when it comes to red wines). In case of finished wine, the following compounds are responsible for imparting different textures and flavor: volatile phenols impart the vanilla flavor, carbohydrate degradation items comprising of furfural yields the toasty and sweet fragrance, the lactones from oak barrels impart the woody smell, the hydrolysable tannins provide the astringency feel to the wine and the terpenes which are responsible for providing tea and tobacco notes to the wine.
Now, not all oak barrels impart the same flavor. The flavor imparted may differ depending on the kind of oak used, the manufacturing techniques of the oak barrels and the chemistry of the oak barrels. Some of the important things to consider when manufacturing barrels from oak would be whether to use American oak or French Oak, whether to hand-split the wood or saw it apart, whether to dry it in kiln or let it air dry, whether to use natural gas or wood fine, whether to boil it or steam it and so on. Thus makers of oak barrels have to do a lot of research and take a lot of decisions before embarking on the process of crafting the oak barrels, which is an extremely complicated one!