Beyond the Barrel: The Secret Life of Oak in Winemaking
Hello Fellow Wine Adventurers!
Over the past several weeks in the lead up to harvest, we’ve worked a lot with oak barrels. Mainly, preparing them for this year’s vintage where some of the wine may either ferment in barrels and/or age after fermentation. Either way, prior to any of this, it requires continual sanitation and ozone gas treatments to disinfectant the barrels so as not to harm the oak’s flavor profile. Because barrels are a huge investment to a winery, and susceptible to molds, bacteria, and fungi, the importance for persistent care and attention can’t be understated. So, perhaps some background on these sometimes-overlooked vessels that we’ve all become so accustomed to seeing in and around a winery is worthwhile.
The obvious question might be, why oak barrels? What is their importance to wine? Now, to save you from a whole history lesson of how oak barrels came to be in wine production, we’d like to suggest that there’s a linear approach to their influence(s) on the grape juice/must (grape juice, skins, seeds and stems; a.k.a. pomace). But, as I’m sure you’ve guessed, it’s not so straightforward. With all the decisions toward the final wine, it’s more like a sine-wave of activity.
Like mentioned earlier, oak barrels can be used as a vessel during primary/secondary fermentation, and/or for maturing wine post-fermentation (aging). With this understanding, the question might become, what is the style of wine to be produced and/or the desired influences and outcomes from the oak? Even before the grape juice goes into a barrel, the winemaker must know how the oak might change the profile, body, structure and texture of the final wine. So, guess what? It makes a difference where the oak comes from (by the way, we could also digress and discuss oak versus other types of wood, but Lacie is keeping me to 1,000 words of less). Like vineyards, oak trees take on their own flavor/aroma characteristics based on geography, climate, soil, growing conditions, etc. Sound familiar? Terroir, or perhaps oak [barrel] terroir? While there are other areas of the world gaining popularity for their oak (Hungary, Slovenia, Canada, etc.) in wine production, many winemakers have traditionally gone with either French or American Oak.
There are many factors that contribute to these selections (and, again, when we say American or French Oak, please understand that the oak comes from many areas in each country, respectively), but mainly it has to do with the porosity (how porous are the wood grains – oxidation elements?), aromas and flavors to be imparted, phenols, and tannin effects. Other elements that oak barrels have on wine during production or aging are the color and body, which are mostly attributed to how much oxygen is introduced into the barrel over time. Notwithstanding, here are more consideration for a winemaker (and you, as a consumer) when understanding oak barrels and their effects:
How long will the wine stay in barrel? As the consumer, knowing this information helps to understand longevity of primary fruit, herbs, flower aromas/flavor characteristics along with any chance of wine oxidation and/or softening of tannins.
Use of old, neutral, or new barrels (think porosity and imparting of flavors/aromas). Typically, barrels used 3-5 times are considered “new.” After this initial use, the aroma/flavor characteristics significantly decline and these barrels now become more for storing wine before releasing.
Amount of toasting to the barrel from the cooperage. Impacts flavors depending on how much the barrels were “toasted” during production [toasting helps the cooper shape the staves during production]. Typically, light, medium and medium-plus are the ranges with flavors measuring equally.
Size of barrel: larger barrels = less contact with wood; smaller barrels = greater contact. This ratio of surface to volume of wine plays an important role in how much the wood imparts to the liquid.
Style of wine. This is a blog all on its own, but some wines definitely benefit from more oak than others (think Bordeaux style), while some wines can be “over-oaked” which masks potential flaws in a wine and/or are desirable flavors/aromas to a specific audience.
Like many aspects of wine, the etiology, transformation, and decision-points all play a key role. Hopefully we’re able to break this down into palatable blogs and help you understand when terms like “new” or “neutral” oak, American vs. French oak are used, they mean something. If there’s uncertainty when purchasing a glass or bottle, please ask. That’s part of the responsibility of those that work in the industry. The only other thing to mention is that oak barrels used in wine production are expensive. Typically, these barrels range from $500-$1600, each! They can be cost-prohibitive to many small producers; hence, our attention to detail over the past six-weeks to prepare them for this 2025 harvest.
Cheers!
