Elsewhere in this issue, Kerry Kirkham surveys the ins and outs of using the growing array of oak powders, chips, cubes and staves that can provide some of the flavors and tannins of oak barrels to tank-based wines. But there’s another, more radical alternative: Make the barrels themselves not from oak, but from stainless steel or plastic.
Wine got along just fine, thankyouverymuch, for several hundred years by relying on clay amphorae—and for another few hundred years relying on barrels of various shapes and sizes. Bottles were closed with corks. Period. Now we have a revival of concrete fermentation tanks, red wines fermented in the barrel and wine packaged in everything from screwcapped bottles to Tetra-Paks. So it’s really no surprise that alternative packaging should make further inroads into the realm of barrel aging—especially when the upstart products are infinitely reusable and vastly easier to clean.
There’s no danger that those atmospheric rows and stacks of barrels are going to disappear, no likelihood that the next fancy winery dinner you go to will feature candlelit tables among the plastic barrels. Stainless and polyethylene can co-exist peacefully with oak, used mainly for specialized purposes, but performing well as role players. Oak-free barrels can’t do all the things that oak can do—but then, oak can’t do all the things non-oak barrels can do, either.
The drum corps
Stainless steel has been a major part of the winery cellarscape for several decades, with tanks and fermentors in every shape, size and configuration. Extending the reach of stainless down to standard barrel size—somewhere between 50 and 70 gallons—was a natural development, especially since metal drums were already a mainstay of other industries. Stainless drums/barrels have been in use in the wine industry for 20 years or so, and they are on the upswing today.
Packaging Specialties in Medina, Ohio, for example, sold its first stainless wine barrel in 1996, according to business development manager Jon Stein. Like many of the producers of barrel alternatives, Packaging Specialties is an all-purpose custom packaging outfit and has been at it for 50 years. Since one of the company’s claims to fame is developing containers for storing de-commissioned nuclear warheads capable of withstanding a 350-mile-per-hour collision, making a wine barrel wasn’t a big challenge. Stein says the company started with a barrel-shaped product but soon realized there was no particular reason, other than traditional aesthetics, for the bulbous middle, which actually made design more complex.
Stein says the stainless barrel business has picked up in the past few years, fueled by concerns for reusability and sustainability. Dean Ricker of Skolnik says that wineries came to his company about 15 years ago and got them into the stainless barrel business, which now accounts for several thousand barrels per year and about 8% of Skolnik’s work. Custom Metalcraft in Springfield, Mo., says the barrel business has taken off in the past 10 years.
In whatever shape and size, with whatever bells and whistles in the way of fittings, stainless barrels have one great advantage over the oak original: They can be cleaned much more thoroughly and much more easily. The inside surfaces of barrels are full of nooks and crannies and hard to get at with even steam or ozone, providing plenty of condos for critters whose role in winemaking is not helpful. Once infested, resanitizing barrels is nearly impossible without destroying the usefulness of the barrel. Stainless is happy to get blasted with whatever cleaning agent you prefer, and it can sit empty for months at a time with no danger of becoming a permanent Brett farm. Some producers feature seamless stainless barrels with no crevices at all inside.
Stainless barrels can be used for 20 years or more—far longer than oak barrels, which usually turn into planters after three or four years. Initial costs are roughly comparable to new oak barrels; both options range widely, depending on the number of custom-designed features (stainless) or the prestige of the forest (oak). But over time, stainless is clearly a good investment. And once the barrel is fabricated, it stays fabricated; there’s no need to chop down more trees the next year. Depending on how you do the calculation, the metal barrel may be a “greener” option than the plant-based version.
But does it age like oak?
Besides looking nifty, oak barrels serve two important functions, flavoring and rounding/concentrating. The flavor part (and its frequent companion, contributions of oak tannin) is fairly easy to approximate in any kind of container with the judicious use of oak products. Oak adjuncts can do the job in tanks, in non-oak barrels. And for that matter, in entirely neutral oak barrels. Indeed, there is something to be said for the degree of control available by adding oak in bits and pieces: a new barrel will give whatever it gives, which may or may not be exactly what the winemaker had in mind, but a series of smaller, sequential oak alternative additions allows for finer tuning.
The other thing barrels do is harder to mimic: the slow dance of oxidation and evaporation that brings a wine’s disparate parts together, softens the rough edges, complexifies the aromatics and lets the wine unfold. This effect isn’t easy to quantify. Sometimes it’s even hard to put in words, but the sacrifice of millions of trees testifies to its power. In this respect, barrels are a little bit like cork stoppers: When they’re bad (leaky, infected, TCA-ridden, wildly variable), they’re very, very bad, and when they’re good, they’re very, very good.
This x-factor is not high on the list of stainless steel’s barrel attributes. A certain amount of oxygen will likely come aboard during racking, topping (if that is ever needed) and sampling. Specialty stopper designers go beyond the standard tri-clover clamp, a thoroughly tight seal, to facilitate tiny but steady oxygen ingress. Evaporation is minimal—either a good or a bad thing, depending on your wine style goals.
This reductive tendency makes stainless barrels more popular for white winemaking, during which oxygen is frequently kept at a distance anyway. If your goal is plenty of lees and precious little air, stainless works just fine. But stainless barrels also are getting a tryout with some high-end red wine producers who like the pure fru it streak that stainless barrels can add to a mostly new-oaked wine.
The major difference between stainless tanks and stainless barrels is, of course, size. Barrique-sized stainless barrels are nicely suited for overflow storage, very small batches, yeast trials (without the influence of oak), blending components and storage of topping wine. The chances of accidental oxygen exposure are less than with small-scale, variable top tanks. And they fit on existing barrel racks.
Graduating to plastics
The plastic—or, more properly, polyethylene—barrel report is in most ways similar to the stainless story. Polyethylene containers, in barrel and small-tank sizes, are easier to clean, happy to incorporate oak adjuncts, non-evaporative, longer lasting and less expensive over the long haul. In addition, they come in a variety of space-efficient, stackable shapes and sizes and accommodate a wide range of openings and fittings.
The combination of plastic and wine still creeps out some folks in the wine industry. But any potential problems of flavor taint were solved by the packaging industry for food and beverage purposes long before plastic wine containers began to appear. If millions of gallons of wine can now get packaged successfully in plastic bags-in-boxes, and if hundreds of thousands of home winemakers can use food-grade trash cans as fermentors every year, polyethylene is surely ready for prime time in wine storage. Schütz in New Jersey, Pasco Poly in Idaho and Flextank in Atlanta are among the major suppliers of plastic wine storage in various sizes.
More than 1,000 U.S. wineries have started using Flextank products since 2006. The company does a good proportion of its business in barrel-sized containers and emphasizes that its materials can do one thing stainless barrels can’t: let in a little bit of air. Flextank offers two thicknesses of polyethylene walls: The “maturation weight” performs similarly to second-year barrels, and the heavyweight acts more like neutral barrels. Following this logic, the heavyweight products are best suited for aromatic whites and the maturation weight for wines designed to develop through planned oxidation. Flextank CEO John Smeaton estimates that the maturation containers allow in about 17 milligrams of oxygen per liter per year, compared to 20-30 milligrams from new oak barrels.
Even if that permeability gets us closer to the traditional oak barrel, poly barrels aren’t going to take over the industry. Like stainless, they are primarily used for small batches, blending components, trials, topping wine and so on, though in some cases, smaller wineries may rely on them heavily for economic and space reasons.
Mostly, what we have is more peaceful coexistence. Stainless and poly barrels aren’t the revolution that stainless tanks and fermentors were, but they have a definite place in winery operations large and small. They work, they get clean, they can save some money and, in some cases, they may even be “greener” than oak.
Tim Patterson is the author of the newly released "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.