Inquiring Winemaker


Will Barrels Go the Way of Floppy Disks?

April 2014
by Tim Patterson

Comparisons, sometimes heated, between making wine with oak barrels and making wine with various barrel alternatives—oak staves, micro-ox, etc.—have been thrown around for a couple of decades now. While much disagreement is still abroad in the land, a number of things have been definitively established, and it’s useful to draw up the balance sheets for both sides.

permeable plastic
The permeable plastic that Flextanks are made of allows oxygen to enter at predictable rates.

  • Are barrel alternatives on the verge of making traditional oak barrels obsolete?
  • Oak products, micro-ox and various tank alternatives do a better and better job of reproducing barrel flavor profiles.
  • Most industry observers, however, think barrels still have a place, especially at the high end.

Barrel alternatives clearly have the following advantages:

• They are far less expensive than barrels.

• They can be applied in various stages of winemaking in more precise doses.

• They are more flexible than barrels when used as fermentation additives (for color stabilization, etc.).

• Several technologies (Flextanks, concrete eggs, micro-ox among them) offer ways to mimic the slow oxidation/evaporation kinetics of barrels, with or without oak adjuncts for flavoring.

• Oak barrel alternatives require cutting down far fewer oak trees.

Standard barrels, on the other hand, are clearly superior in at least three respects:

• They have hundreds of years of tradition on their side.

• They look really cool in the winery and in promotional materials.

• They can easily be recycled as planters after their useful lives are over.

Are barrels obsolete? Or, at the very least, do barrels have the same issues as natural corks: plenty of worthy history, a certain romantic appeal, great results when they work right, but maybe more trouble (and money) than they’re worth for the majority of wines?

Barrel basics
Oak barrels in various forms have proven amazingly useful to the development of the wine industry—as well as the development of the individual wines matured inside them. Despite all the buzz about the back-to-amphorae movement, virtually all premium reds and many whites are aged and/or fermented in barrel, and in recent years $10 wines have spent at least some time in wooden vessels.

This remarkable track record is all the more noteworthy because the adoption of barrels as standard containers had almost nothing to do with the characteristics for which they are valued today. Barrels had multiple advantages over stone wine vessels; they were lighter, more portable and far less likely to crack open. The distinctive flat-ended, wide-bellied shape made them easier to roll around and vastly stronger than a wooden wine cube would be. The common shapes and sizes developed hundreds of years before anybody knew about cis-lactones or, for that matter, about the existence of oxygen as a discrete element in air, let alone oxygen transfer rates. Talk about dumb luck.

Barrels turned out to do several things that made wine better and tastier. The most obvious contribution is flavor, and even those of us who gag at over-oaked wines will happily admit that the marriage of oak and wine has passed the test of time. Over the centuries, wine styles have swung from oxidative to reductive and back again, from sweet to dry, from modest alcohols to fire-breathers, but the value of a little oak has been a constant, a keeper. Barrels also yield oak tannins, contributing to the structure and mouthfeel of wine and playing a useful anti-oxidative role.

With less fanfare and much less controversy, the slight permeability of barrel staves and the seams between them allows for a very gradual, gentle combination of oxygen coming in and evaporated liquids (water, ethanol) going out. The sensory effects of this slow-mo exchange show up as more rounded, integrated, concentrated wines—as the French say, élevage (raised up). Even older, flavor-neutral barrels—or large-format puncheons and casks that contribute less oak flavor—still do the oxidation/evaporation dance in a way stainless steel and glass can’t.

Barrels are a hard act to follow.

Barrel alternatives
I use the term “barrel alternatives” to include the entire range of products and technologies that aim to reproduce one or more of the functions performed by barrels, so they are not all simply “oak alternatives”; and in any case, so-called oak alternatives are, in fact, made out of oak—a true oak alternative might be chestnut or redwood.

For contributions of flavor and tannin, oak is available in a dazzling number of forms, representing every major oak forest on Earth, at any toast level or combination thereof, in staves, inserts, spirals, chips, beans, powders and extracts. Besides costing a whole lot less, these chunky oak options give the winemaker more control of dosages and exposure: Stuff can be taken out, put back in and weighed precisely.

Other technologies mimic some or all of the oxidation/evaporation tango that porous/permeable barrels play host to. Micro-ox systems dispense carefully controlled burps of oxygen at pre-determined intervals during critical winemaking phases. Flextanks replace wood with permeable plastic, letting in oxygen at predictable rates. Concrete tanks, egg-shaped and otherwise, allow for a similar bit of breathing.

Wineries can mix and match all these options any way they choose: A given wine might be tank-fermented with a micro-ox energy boost, then aged in Flextanks with oak inserts, and finally blended with a batch that grew up in a concrete egg. Lots of flexibility, lots of choices, lots of control and lots of savings.

So, is there anything left that barrels alone can do? If so, what is it, and how does it work?

Industry opinions
Using the patented Inquiring Winemaker™ methodology—interviewing a lot of people who know more than I do—I talked with several representatives of various barrel and non-barrel providers at the Unified Wine & Grape Symposium in Sacramento, Calif., in January and followed up with phone calls to several others. My list included Phil Burton of Barrel Builders, Jeff McCord of Stavin, Guillaume de Pracomtal of Chêne & Cie (which combines Taransaud barrels, Canton Cooperage, and Xtraoak oak adjuncts), John Smeaton of Flextank, Thomas Leclerc of micro-ox supplier Vivelys/Oenodev and Travis Simmons of Sonoma Cast Stone. The goal wasn’t to amass more technical detail on the performance of this or that product, but to get overall impressions from people on the frontlines of the barrel battle. Do barrels still provide something special, something non-reproducible? And if so, what is it, and how does it work?

The consensus, including among the people making their livelihoods from barrel alternatives, was that traditional barrels contribute some unique gifts to winemaking-—but that the alternatives are extremely good and getting better by the day, not just for the mass market but for very high-end wines.

It’s true that two of the people I talked to—Stavin’s McCord and Flextank’s Smeaton—started our conversations with the same line, that barrels are better as planters than the alternatives. I began to wonder if they had both gotten a memo with talking points. Further conversation, however, revealed broader viewpoints.

First, the flavor question. McCord is the longtime research director for an oak products company, Stavin, which has the explicit goal of trying to match the flavor profiles of barreled wine with its various bits and pieces. Stavin (and some other adjunct producers) air dry their wood, just like the cooperages, rather than kiln dry it; fire-toast their staves, just like the cooperages, rather than oven roast it, and then chop the staves up into handy chunks. After many years, McCord says, “There are certain flavors I can’t make happen in stainless or Flextanks, but we’re getting closer. We’re as good as or better than used barrels.”

Burton noted that right after the repeal of Prohibition, oak chips in wine were illegal; they were banned because they had been used in whiskey production to create cheap color. Eventually, that rule was lifted, but Burton still thinks that “today, in spite of everything, no one has duplicated the slow melding of wood and wine and the slow process of oxidation. Yes, there are some real good copies; a lot of people have come close, and they will get closer.”

On the oxidation front, Smeaton says his Flextanks allow oxygen transfer at rates comparable to second-fill barrels. Leclerc says that with careful micro-ox and oak products, excellent wine is being made all over the world. The harder part, he says, is reproducing the increased concentration that comes from long (24-month) barrel aging; it is much easier to get a little oxygen into a wine vessel than to allow evaporation of ethanol and/or water to escape out. This concentration effect is particularly important in certain spirits, which may spend several years in barrel; Leclerc says the Vivelys R&D team is closing in on a solution for spirits.

Several people I spoke with said there may be something special about the shape and size of barrels that is hard to mimic in larger and differently shaped storage formats, though the importance is hard to quantify. We all know (or at least believe) that bottled wine ages differently in larger or smaller bottles. Guillaume de Pracomtal noted that the rounded shape of barrels had two small but significant advantages: at the top, only a very small portion of wine surface is exposed to air near the bung; and at the bottom, the curvature makes for compact, settled lees that touch less of the wine surface for reds but are easily available for stirring with white wines.

By far the most intriguing reason advanced for why barrels are special came from Thomas Leclerc: their randomness. Barrel variation (see “Do You Know What’s Inside Your Barrel?” in the March issue of Wines & Vines) guarantees that a bunch of barrels are going to produce a bunch of slightly different results, and if you want that in your wine blend style, you’re much more likely to get it from barrels than from a single, uniform large tank.

Barrels also benefit from a kind of Occam’s Razor simplicity: Barrels play all these various wine-development roles in a single product, not a combination of four or five. It’s hard not to believe that the integration of several functions in one space somehow makes for a more integrated result.

The barrel alternatives folks point out that wines made with their techniques have won a ton of medals and held their own in some blind tastings. They assured me that there are some very pricey wines made through alternative means, in whole or in part, though their producers don’t make a habit of advertising that fact. (Wineries are oddly selective in what they divulge and don’t: The use of concrete tanks is worn as a badge of honor, though Flextanks are kept well out of sight. Go figure.)

Everyone agreed that for a huge part of world wine production, barrel alternatives make a lot of sense; they meet the expectations of their wine-drinking audiences and in many cases bring out all that can be brought from good-but-not-great grapes. Having the alternatives around gives any winery more tools and options. But where the raw materials of wine are special, when grapes show the potential for complex, long-lived, transcendent wines, barrels should be part of the program—at least for now.

Which means there probably won’t be a glut on the wine barrel planter market any time soon.

Tim Patterson is the author of “Home Winemaking for Dummies.” He 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.

Posted on 04.07.2014 - 06:42:42 PST
Fun piece. Particularly enjoyed the three clearly superior attributes of standard barrels, including looking cool in the winery and in promotional materials.
Tom Gable