With the red harvest complete, and extended macerations underway, I’m starting to think more concretely about how barrel aging will affect the wine and how we can use this understanding to enhance quality. It goes without saying that barrels are not neutral vessels. Aromatic substances in oak quickly diffuse into wine, and some of these combine with or react with substances in the wine to create new flavors. It’s a bit like using spices while cooking. A little bit can enhance the natural flavor of the ingredients, adding complexity and depth. Too much can hide great ingredients, and faulty ones. Oak also contains tannins that have both beneficial and detrimental effects on wine.