Both American oak and French oak contribute aromas, flavors and tannins to a wine, but the results are quite different. French oak is much tighter grained and less dense than American oak, thus imparting more subtle flavors and firmer, but silkier tannins. Since American oak is denser, it can be sawn instead of hand-split, which makes it considerably cheaper than French oak. American oak is sweeter and contains more vanillin compounds and tends to impart more obvious, stronger and sweeter aromas and flavors.
Besides the origin of the oak barrel, what are the other important factors that impact the oak influence on a wine?
The other important factors include the age of the oak, the level of the toast, and the size of the barrel. The newer the oak barrel, the more oaky aromas and flavors will be imparted on the wine. By the fourth or fifth year of use, the flavors are negligible and the oak is termed ‘neutral’. Barrels can be given a high, medium, or light toast, and the higher the toast level, the more oaky aromas and flavors will be imparted on the wine. Lastly, the size of the barrel is significant because the smaller the barrel, the greater the impact will be of the oak aromas and flavors.
Why are barrels the vessels of choice for the storage of wine?
The use of oak has been prevalent in winemaking for at least two millennia, first coming into widespread use during the time of the Roman Empire. Over time, winemakers discovered that beyond just storage vessels, wine kept in oak barrels took on properties that improved it by making it softer, and in some cases, better tasting. Furthermore, the porous nature of an oak barrel allows some levels of evaporation and oxygenation to occur in wine, but typically not at levels that would spoil the wine. The evaporation allows the wine to concentrate its flavor and aroma compounds, and the small amounts of oxygen act as softening agents on the tannins of the wine. Lastly, the different origins of oak give winemakers great flexibility in fine-tuning the flavors, aromas, color and tannins
they want in the finished wine.
Originally published in our Wine Press' Wine Wizard, Casey Flat Ranch Vineyards edition featured in our Gold Wine Club.