Red Wine Barrel Fermentation
For most of us, the mention of “barrel fermentation” immediately conjures up images of Chardonnay bubbling away in row upon row of French barriques, soaking up oak, impatiently waiting for the malolactic to kick in. But for an increasing number of high-end producers, some of those barrels are full of red grapes, a way of ensuring that fruit and wood intertwine from cradle to grave. And no, they’re not using long-handled tweezers to get the grapes in and out.
There isn’t a lot of science on record to tell us exactly what does and does not get accomplished by this technique, but there are plenty of winemaker testimonials about the benefits of early oak-fruit integration for mouthfeel, color stability and aromatics. Like the fans of concrete fermentors—last month’s topic in this space—advocates of red wine barrel fermentation say their vessels of choice do things stainless tanks can’t. The concrete crowd argues that their wines get some air without any influence from oak; the barrel boosters say their wines get oak, and then some more oak.
Suddenly, all that gleaming stainless seems so...yesterday.
The old is new all over again
Like everything else in wine, barrel fermentation—or something very much like it—has been done before. Go back 40 years—I know many of you weren’t born then, but trust me—and nearly all the world’s wine was fermented in either wood or concrete. Indeed a few relics of that era (redwood and otherwise) are still around, mainly as tourist attractions. The rise of stainless was also the rise of sanitation and temperature control, both very good things. But the winemaking sensibility moves on restlessly, relentlessly.
Jeffrey Stambor has been making wine at Beaulieu Vineyard for two decades. “The trend has been to get wines in contact with wood as soon as possible,” he says, “starting with barrel-fermented Chardonnay 15 years ago, giving more complexity and integration. For reds, when I started at BV 20 years ago, everything went into barrel very clean, making for disintegrated fruit. Then we started putting reds into barrel dirtier, then pre-malolactic, and kept seeing huge difference in complexity and integration.”
The leap, or perhaps logical extension, to all-barrel, all-the-time at BV came with experimental batches in 2005; by the 2008 vintage, the entire production of the flagship Georges de Latour Private Reserve Cabernet Sauvignon was born in 600 spanking new French oak barrels, each getting 400 pounds of whole berries, all tied together in a complex OXOline rack system equipped with rollers to turn the barrels for cap management—rotary fermentors on a micro scale.
Oak integration from day one
Other producers use barrels for red fermentation on a smaller scale, sometimes simply because they make a lot less wine than BV, sometimes because they feel the technique gives them an additional blending component, not a total style. But one way or another, the winemakers and cooperage representatives I talked to all came back to the same concept as Stambor: better, earlier integration of wine with oak in all cases—brand-new, medium-plus to heavy toast oak.
Keith Emerson at Vineyard 29 in Napa, for example, says that “early oak integration brings in another layer, another element, to the wine.” For Jerome Aubin of Artisan Barrels in Oakland, Calif.,“The idea is to integrate oak tannins during primary fermentation, and get richer and softer mouthfeel as a result, as well as higher tannins than in tank fermentation.” Aubin also notes the early extraction of lactones, adding to mouthfeel, and “rounding off edgier tannins.” Philippe Michel of Oak Tradition in Santa Rosa says the technique “helps with mouthfeel and the body of the wine, and does it sooner.” Several people felt the barrel-fermented wines seemed more “finished” right out of the box.
“Integration” is, of course, a slippery term, a little like “finesse,” a quality best appreciated in the eye—or taste buds—of the beholder. But the composite picture I got from my series of phone interviews was that improved integration means the sooner oak is applied, the less obvious it is; it becomes part of the package from day one—not sticking out as an afterthought or alien add-on. And if that’s what it accomplishes, let’s hear it for barrel fermentation.
Besides the elusive matter of integration, proponents cite several other benefits. Since polymerization of pigment with tannin clearly plays an important role in long-term color stabilization, barrel fermentation gets that process going sooner. Philippe Michel says oak tannin also helps absorb and neutralize vegetative characteristics. David Llodra, director of research and development at Napa’s World Cooperage, emphasizes a different organoleptic contribution: The combination of fermentation kinetics with wood yields furfural compounds, with distinctive coffee and tobacco characteristics that can’t be concocted in the absence of yeast activity. (This part, at least, is well documented in the scientific literature.)
Some adherents of barrel fermentation emphasize the practical benefits. Emerson points to the Petit Verdot that Vineyard 29 harvests every year: With less than a ton of fruit, does it make more sense to process that mini-batch in three or four barrels (barrels that will later be used for aging), or to waste a 10-ton tank on a mini-fermentation? Emerson says the technique works best for what he calls “power lots.” Barrel fermentation helps tame rob ust, tannic grapes like Petit Verdot or hillside Cabernet, but it can overwhelm lighter batches.
Along the same logistical lines, winemaker Marbue Marke at Napa’s Caldwell Vineyard says that small-scale fermentation is the best way to take advantage of a vineyard with 18 separate blocks averaging two or three varieties and six clones per block.
Complications and conjectures
On the practical downside, working with all those barrels generates more work and more mess. Some barrels, like those from Baron sold through Oak Traditions, come equipped with small doors in the barrelhead that are large enough to get grapes in and out. But some wineries just pop and unpop their own barrelheads, sometimes keeping them upright and punching down the caps. Stambor’s cellar crew at BV has developed new coopering skills: Those hundreds of barrels have the heads popped off before filling, then re-attached for fermentation, then removed again for pressing, and finally put back on for aging. Yes, there is some overhead.
Achieving proper fermentation temperature presents another practical issue. While some of the folks I talked to had not encountered problems in getting peak temperatures high enough, some had. BV’s solution: heat the room, a special facility devoted only to the Georges de Latour Cab. Marbue Marke at Caldwell also has a warm room available when needed. Vineyard 29 uses floor heaters and puts tarps over the barrels when necessary to get temperatures up, but Keith Emerson also notes that slightly cooler temperatures are actually an advantage with the “power lots” that go into barrel, avoiding over-extraction.
As usual, we don’t have a lot of chemical or sensory science to help evaluate the technique. No one I spoke with could refer me to rigorous studies of the impact of barrel fermentation on phenolic composition, or how that might compare with tank-fermented wine, or with tank-fermented but barrel-aged wine a year later. What exactly might the higher temperatures during fermentation extract from wood that wouldn’t come out in cooler storage? How does oxygen access compare to other fermentation modes, and does that matter much?
Nor did I come across organized sensory data on the impact of barrel fermentation on red wines, though certainly all of the wineries that have adopted the practice have done trials and tasted their way through the results. If the wines come out more integrated and finished, can trained testers identify that? Picking out barrel-fermented Chardonnays from their tank-fermented cousins is not that hard; what about barrel and tank Syrah?
Jeffrey Stambor acknowledges that BV has not done rigorous side-by-side comparisons, but he hopes to do more lab work this coming harvest. In BV’s informal sampling, total phenolics measurements for barrel-fermented wines were surprisingly high, even as sensory evaluation rated the wines smoother and more supple.
While we wait for the science, two things strike me about this new/old technique. First, for those who think California wine is already too oak-centric, the vine-to-barrel approach may seem like madness. Just what we need—more oak. In contrast to the minimalist winemaking philosophy that less is more, oak integrationism preaches that more is less: the more oak you lay on the wine, the less you notice it—and the sooner, the better. What’s next—oak bottles?
Second, it’s intriguing to note that the descriptions of barrel benefits I collected were surprisingly reminiscent of many of the comments I solicited for last month’s column about the advantages of fermentation in concrete. The concretistas are trying to avoid oak, not integrate it, but still they point to wines that “come together sooner,” seem more “finished” and accessible early on, show improved texture and mouthfeel, and so on—not that different from the barrel boosters.
Keith Emerson, who has both options in his cellar at Vineyard 29, sees a lot of similarities in the two more natural, more oxygen-friendly methods, compared to stainless. “Concrete and barrel fermentation do overlap: both more porous, not as tight, not completely reductive, producing rounder mouthfeel, speeding everything up a little bit.” In other words, after decades in which tanks have reigned supreme, these old-time materials offer a breath of fresh air in more ways than one.
It certainly can’t hurt that small-batch fermentation, done in whatever vessel, is likely to get more attention. All of these folks are smart winemakers who make good wine, and if they say barrel fermentation does great things, or concrete has special properties, those options are probably worth a try. But for the record, I would not advise jettisoning all your stainless just yet.
Tim Patterson writes about wine and makes his own in Berkeley, Calif. Years of experience as a journalist, combined with a contrarian streak, make him interested in getting to the bottom of wine stories, casting a critical eye on conventional wisdom in the process. Contact him through firstname.lastname@example.org.