For at least 200 years, winemakers have been storing many of their products in French oak barrels during the fermentation process. In fact, many of the flavors experienced by consumers of the finished wine are created by the oak itself, not the grapes. Because these French oak barrels can impart flavors that overpower the fruity or citrusy elements of the grapes, some winemakers now use stainless steel vessels during fermentation to bring out the true nature of the grapes. The result of this stainless steel fermentation process is called an unwooded or unoaked wine.
There are a number of reasons why some winemakers are now producing wine without the oak flavor. One of the main reasons is consumer demand for a lighter, fruitier white wine without all of the overwhelming flavors created by oak barrels. The grapes used for white wines are especially delicate, with very complex aromatics that are often lost when the wine is stored in oak. Stainless steel containers, on the other hand, do not impart any additional flavor elements. Unoaked wine is said to emphasize the natural flavors of the grapes, along with elements of the soil in which they grew.
The most common variety of unoaked wine marketed today is the white Chardonnay. For some wine enthusiasts, this may come as a bit of a shock, since the Chardonnay grape is not known for its aromatics — much of its traditional flavor is derived from the French oak barrel. An unoaked Chardonnay is said to be more easily matched with foods than the traditional oaked variety, however. Other white wines, such as Riesling and Gewurztraminer, are not often labeled as unoaked, but they are traditionally fermented in stainless steel. The light flavor of these wines makes them very popular as table or dessert wines.
Currently, Australian and New Zealand-based vineyards produce much of the unoaked wine available. Many winemakers use screwcaps instead of cork when bottling them. Unoaked varieties are often released earlier than other wines and generally have a longer shelf life than traditional wines after they are opened.