Oak is so intertwined with the world of winemaking that when you think of a classic winery, no doubt caves full of candle-lit barrels packed from floor to ceiling come to mind. Oaking is most associated with red wines, especially the more robust wines like Cabernets and Zinfandels. White wines are typically not oaked, with Chardonnay being a clear counterpoint to that assumption. Seeing the positive impact that oak has on grape wines, I reasoned that oaking could improve our wines as well, and so I set out on a multiyear journey to explore how to best improve our wines using oak.
In order to enhance the wine without overwhelming the unique notes of its taste and bouquet, winemakers consider a variety of oaking factors, including the geographic source of the oak, level of toasting, how to best introduce the oak to the specific wine, and the duration of the oaking. Oak used in winemaking is generally sourced from either France or the USA, although Hungarian oaks can also be used. Oaks can also be toasted to varying degrees, which has a major impact on the flavor characteristics imparted to the wine. Winemakers classically oak their wines by filling oak barrels with wine and letting them sit in the barrel for anywhere from six months to three years, depending on a variety of factors. Oak adjuncts such as oak chips, oak spirals, or oak staves can also be used to pass on oak flavor into wine aged in stainless steel tanks. Oak adjuncts make it easier for a winemaker to utilize a variety of oaks and typically greatly accelerate the oaking process.
For our fruit wines, oak adjuncts have worked well as we typically produce about ten gallons at a time, and such volumes aren’t well suited for barrel aging also, oaking 1-2 gallons at a time under different conditions has allowed us to explore several options using low production volumes. For example, pictured below is our Rochoso Blueberry aged over a variety of oaks. From left to right, we have the unoaked wine, untoasted American oak, lightly toasted American oak and lightly toasted French oak. The visual differences are a result of the oaking process, with increasingly darker oaks creating increasingly richer colors. Which type of oak, toasting level and method is best for each wine? Luckily, there is no right answer to these questions since it all depends on what characteristics the winemaker wants to impart on the wine as well as the flavor preferences of the wine drinker.
A fun bonus of oaking: after using the oak for the winemaking process, you can upcycle that oak in the world of distilled spirits. I first encountered this idea in London’s Heathrow airport at a shop dedicated to selling scotch and whiskey from the British Isles. One of the Scotches I tried had an unusual color and a slight sweetness, and the shop attendant explained both were because the Scotch was finished by aging in a barrel that had previously been used to age sherry. Cross-category spirit aging, along with wine and beer casking, has become very common in recent years, and I was interested in seeing what impact oaks aged in our Rochoso wines would have on whiskey and other spirits. As you can see in the picture of post-aging oak chips below - from left to right: Rochoso Blackberry, Rochoso Cranberry, Rochosos Blueberry, and Rochoso Raspberry - the oaks absorbed a substantial amount of color compounds from the initial wine, so we thought the post-Rochoso oaks could provide some very interesting notes when used to finish whiskey or other spirits.
