The use of oak has a huge impact on the style of a wine. It is not just an essence added to provide aromas. Oak influences the wine texture, stabilizes it and helps the integration of tannins, providing a more pleasant and round expression, and helping its aging potential.
With Pablo Martorell, our Head Winemaker at The Vines of Mendoza, we are in a constant search of perfection. We look at every single detail and decision that can help give a unique character to each of the 200 different wines we ferment. Some of these decisions are about the oak choice are well known, such as new or used? French or American? But there are more complex decisions made as well to drive the quality and character of a wine.
One important aspect is the way the oak is aged. How the oak is aged affects the perceived aromas of a wine. If the staves that will be used to build the barrel are aged outdoors but out of the sun, these are called heart staves. You can identify coconut, violet, cinnamon, black pepper and nut aromas in these staves. On the other hand, barrels can be built with staves that have been aged on sun exposure and are influenced by wiskilactona, a compound that produces aromas like vanilla, nutmeg, paprika, cumin and dry fruits.
At The Vines of Mendoza we look to create complex wines using 1) French oak made with 100% heart staves, 2) with 100% sun staves and 3) even some wines with 50% heart staves and 50% with sun staves. This creates a better balance of aromas in our micro-vinifications.
To create this differentiation we have to add different types of toasts, generally classified as regular, medium or strong, with the barrel bottom (usually referred as foot)being toasted or non-toasted. 85% of the barrels we use have medium toast with bottoms non-toasted to obtain a better balance and expression of the fruit and terroir. The remaining 15% we use have a stronger toast with the feet toasted to obtain stronger oak notes.
Pablo has also designed the barrels we use for barrel fermentation for red wines. In order to better observe the behavior of the cap inside the barrel, we ordered a few barrels with glass feet. Pablo designed this barrel with a transversal barrel inside that helps break the berry cap when the barrels are rotated. He also determined we should add a stainless steel cap to avoid opening the feet of the barrel when filling them. These fermentations are performed using the OXOLine modular wine barrel stacking system, which allows us to save space and rotate more efficiently.
So, you can see that the choice of oak requires quite an education. Good use of oak can provide amazing results without negatively impacting the expression of the wine varietal. It it truly astounding to see what can be created with a little experimentation.