Courtesy of Progeny Winery

Plus, how they affect the wine they're aging.

Jonathan Cristaldi
September 25, 2018

Whether you've ever visited a winery and embarked on a tour, or just seen them the movies, if someone says the word winemaking to you, you might conjur up an image of a massive cellar holding stacks upon stacks of large oak barrels. Or maybe it's a room filled with rows and rows of tall, flashy stainless steel tanks. But if this magazine's recent foray into Georgian wine has taught us anything, it's that winemaking doesn't have to take place in a traditional barrel or tank. (In Georgia, they ferment and age wine in beeswax-lined earthenware jars called qvevris.)

Step inside some of California's most progressive wineries these days, and you'll see concrete tanks instead of stainless, in unusual shapes at that. More than a few have taken cues from at least two of France’s greatest producers—Château Petrus in Pomerol and Cheval Blanc in Saint-Émilion—which rely on concrete vessels to produce some of the most renowned wines in the world.

Why concrete? For the most part, these tanks are used during the fermentation process, and winemakers love them for their microporosity. Stainless steel won’t impart any flavor or oxygen, while brand new oak barrels will impart lots of flavor and allow for a great deal of oxygen exchange. Concrete is somewhere in the middle—allowing for extremely slow, trace amounts of oxygen exchange. According to some winemakers, concrete will even impart a kind of mineral element in wine. This last point is extremely controversial, however, as many winemakers say there’s no exchange, especially if concrete is lined with an epoxy. They attribute any mineral overtones, or bright aromatics, to the wine’s mouthfeel and the natural flavors shining more from grapes, all thanks to concerete’s neutral impact.

As far as an investment is concerned, concrete isn’t cheap. Steve Rosenblatt, president of Sonoma Cast Stone, which has designed and built tanks for many wineries in Napa and Sonoma, explained that something like the increasingly popular concrete egg tank, which takes roughly 16 weeks to produce, can cost as much as $120,000. That’s because concrete eggs often start out as drawings, are then 3D printed, perfected, and turned into heavy-duty styrofoam and fiberglass molds. Once a mold is designed, subsequent eggs can be produced for roughly $10,000 to $14,000 each. It should all give you a little perspective on the price label of that $50 price tag—or more— on that wine list.

Whether it's oak, concrete or something else entirely, alternative wine tanks are a sight to behold—to say something nothing of the wine they produce. Below are 11 of some of the coolest tanks out there, complete with descriptions of how they impact the wine. 

1. Concrete Tanks at Rudd Oakville Estate (Napa Valley)

Matt Morris

For the new tanks at Rudd Oakville Estate, winemaker Frederick Ammons tapped the same mason who designed the tanks at Château Petrus in Bordeaux. Poured in four stages—the foundation and legs, the floors, walls, and the roof—that each take nearly a month, the concrete is a mixture of filtered well-water and some 60 tons of rocks, culled from their own vineyard. “We feel there’s a real continuity of our terroir,” says Ammons. “It won’t exactly impart flavors, but this is part of the philosophy. The tanks are so massive and heavy themselves that even as fermentation goes on, you don’t have to cool the tanks like you do with stainless steel. So you have a more natural fermentation, and maybe longer fermentations, and that lends more textural and more aromatic notes than you get from stainless steel aging and fermenting. Like a used barrel, concrete imparts certain notes. There’s yeast from previous fermentations and other things, which is part of the magic of an older cellar.”

2. Clay Amphoras at Saxum Vineyards (Paso Robles)

Ron Bez

In similar fashion to Rudd, winemaker Justin Smith of Saxum has taken “terroir taste to its farthest extreme,” according to Travis Simmons of Sonoma Cast Stone, which crafted Saxum’s concrete eggs. “He dug out caves on his property and sent us the rocks. We pulverized the rock and made the concrete tanks, which were in an amphora style.” Glycol temperature control systems—the same ones that grace stainless steel tanks—are “embedded in the concrete walls of the Amphorae, so it’s not in contact with the wine,” Simmons says, “so there are also no hot or cold spots because it’s embedded, rather than wrapped around the tank.” The egg shape is important because there are no corners or pockets for the fermenting wine to stagnate in. Amphoras help keep the caps (the crushed grape skins that float to the top of the tank if fermented together with the juice) submerged, allowing for less manual punchdowns.

3. Reverse Egg at Progeny (Napa Valley)

Courtesy of Progeny Winery

Winemaker Sean Capiaux of O'Shaughnessy Estate Winery up on Napa’s Howell Mountain and Proegeny Winery on Mount Veeder Estate also has a few tanks from Sonoma Cast Stone. One of them is this extremely cool Amphora, which looks like a reverse egg and holds 320 gallons. He also has a small concrete egg form French supplier Nombolt. And yes, Capiaux is of the mindset that the tanks do add a mineral component to his wines.

4. Conical Concrete Tanks at Continuum

Steven Rothfeld

Continuum Estate's Conical Concrete tanks are six feet tall, with a diameter of 82 inches. They're mounted on top of a concrete slab that is 42 inches off of the floor. They each weigh 9,200 pounds and can hold 925 gallons—or about 3.7 tons of fruit! Produced by Sonoma Cast Stone, they are composed of a proprietary concrete mix they call earthcrete. “We feel that the concrete tanks help soften both the tannins and the acidity, giving the wine a greater sense of refinement and harmony,” says winemaker Steve Nelson, who prefers to use them for earlier picked Cabernet Sauvignon and Petit Verdot. Echoing Nelson, winegrower and proprietor Tim Mondavi believes the tanks “develop more elegance and tenderness of texture,” for those varieties. Mondavi adds: “Concrete or various types of earth or clay are also among the oldest containers known to man and among the oldest used for wine.

5. Giant Buried Amphora at Erzetič Winery (Slovenia)

Winemakers in Georgia have been aging and fermenting wines like Ribolla Gialla in giant, clay amphorae called qveries, which they bury in the ground to help regulate temperatures, for centuries. In addition to aging and fermetning wines, they were also used to transport the stuff—a fact that came to light after the discovery of ancient shipwrecks carrying the vessels. Today, the winemakers are embracing this traditional method for the rich texture that results from more contact with lees, the yeasts that settle toward the bottom. Italian producer, Josko Gravner, is often credited with helping revive interest in these vessels stateside.

6. Massive Epoxy-Lined Cement Tanks at Donnafugata (Sicily)

Jonathan Cristaldi

On a trip to Italy a couple years back, I was in awe of the towering cement tanks at Donnafugata, Sicily’s standard-bearer of fantastic wines from local varieties. Unlike most concrete tanks in the U.S., these are lined with an epoxy-sealant, which ensures there's no contact with the concrete. But the big advantage is that it allows for a really easy clean-up—they basically hose down the tank and it’s good to go. The tanks are so big that the massive amount of lees (dead yeasts) that collect from aging wine has to be raked out. But it smells wonderous—like freshly baked brioche, mixed with crushed white flowers.

7. “Poured in Place” Concrete Tanks at Ovid (Napa Valley)

Courtesy of Ovid. Napa Valley

The folks at Ovid refer to these beauties as “Poured in Place” because instead of being cast and forklifted in, they were actually built as part of the building. “Each tank wall and floor is approximately 10 inches thick,” says Ovid’s Ian Leggat. “This was done initially for seismic safety, but we quickly realized the huge benefit of that all that concrete represented—incredible temperature stability during fermentation. All that concrete acts like a big, warm hug around each fermentation, maintaining a stable, steady temperature, which we feel helps the final expression of the wines. They help the wine to transparently express our red, rocky mountain top as beautifully as possible.”

8. The “Neubarrel™” at Frog’s Leap Winery (Napa Valley)

Sonoma Cast Stone

Here’s something you’ve never heard of: The “Nubarrel.” With the inside made up entirely of concrete or possibly also containing oak chips or even oak staves, it's like a cross between a concrete tank and an oak barrel, and according to Steve Rosenblatt, president of Sonoma Cast Stone, producer of the Nubarrel, it's a highly efficient way to ferment and age. “The average time a winery keeps a barrel is four years,” he says, noting that some wineries “spend 2.5 million every year on barrels and those barrels end up in garden shops around the country.” Not so with this one, which is built to last 10 times as long. Importantly, too, unlike a traditional oak barrel, which requires removing the “bung” (and letting in oxygyn) when you're tasting the wine, the Nubarrel has an air-tight spout for daily sampling. It also has a sparging stone inside, which looks like a metal rod with micro-holes in it. Hooked up to an oxygen tube, winemakers can “micro-oxygenate” wines, which helps soften tannins for early consumption in highly-tannic varieties like Cabernet Sauvignon. At about 42” square 54” high, it can hold 240 gallons, or four barrels-worth, of wine. 

9. Concrete Tanks with Fiber Optic Lighting at Sterling Vineyards (Napa Valley)

Sterling Vineyards

These are just cool—custom tanks that included some fiber-optic lighting. True, the lighting is just an accent to the tanks and doesn’t actually impart anything to the wine, but if you visit Sterling, you might want to break out into a dance party. Glow sticks, highly recommended.

10. Wine-Glass-Shaped Concrete Tanks at Cheval Blanc (Saint-Émilion, Bordeaux)

View this post on Instagram

#chateauchevalblanc

A post shared by flo (@magicflo) on

Behold! The pristine barrel room at Château Cheval Blanc. Something about this photo makes me want to reach out and take a bite out of these tanks. Is it just me, or do those look like giant marshmallows? Beautifully shaped like a wine glass, each of the 52 tanks is devoted to an individual plot of vines, tailor-made to allow specific amounts of oxygen-interaction for that plot. These are the Rolls-Royce of tanks.

11. Upright wood barrel fermentation tanks at Dana Estates (Napa Valley)

© Erhard Pfeiffer 2009

These are some impressive wine barrels. Massive, upright wood barrel fermentation tanks at Dana Estates are made by Taransaud, one of the premier French barrel-makers. (It's interesting to note that French forests are managed by the state, and the wood is auctioned off each year.) Each tank weighs about 2,200 pounds, and winemaker Chris Cooney says they use the tanks for fermenting red grapes. “This is the first stage in the winemaking process, where we put whole grape berries (stems removed) in the tanks and then let the natural yeast on the grapes ferment the grape juice in contact with the skins and seeds into wine,” he explains. “The wood tank provides good insulation to moderate the speed of temperature change during the fermentation process. This allows for smoother texture and less astringency in the finished wine."