Define 'oak aging' and its impact on wine.

Oak aging refers to the process of maturing wine in oak barrels, which significantly influences its overall profile. During this maturation process, the wine interacts with the wood, leading to several important effects. The oak contributes distinct flavors and aromas, such as vanilla, spice, and toasty notes, which enhance the complexity of the wine. Furthermore, oak aging can also impact the texture by softening the tannins, thereby creating a smoother mouthfeel. This method allows for a slow oxidation process that helps integrate flavors and develop the wine's character over time.

The other options do not accurately represent the role of oak aging. Clarification of wine to remove sediments is a different process unrelated to the flavor and texture enhancement provided by oak. Fermentation techniques, especially for sparkling wines, do not involve oak aging as a defining factor. Lastly, the increase in alcohol content is primarily a result of fermentation rather than the aging process in oak. Thus, the maturation that occurs during oak aging is key to producing wines with enhanced depth and richness.