The Revival of Nero’s Wine | Craftsmanship Magazine Skip to content

The Revival of Nero’s Wine

Throughout history vintners used clay vessels to age their wine, until the French discovered the marvels of the oak barrel. Now—for fun, for distinctly different flavors, and to save some fine old trees—a few wineries are giving clay a second chance, Roman style.

Theme: The Art of Alcohol



Materials: ,

top image
For the past five years, John Fetzer, formerly of Fetzer Vineyards (the winery famed for trailblazing biodynamic wines) has been trying to blaze yet another new trail: making interesting wines with modern versions of the ancient clay barrel


  1. Container Wars
  2. “Flavor Bursts”
  3. The Taste of a Good Story
  4. The Celts and The Gauls
  5. For More on the Subject...

On a postcard-perfect fall day on the eve of the 2015 wine grape harvest, the cement crush pad at John Fetzer’s Saracina Vineyards in Mendocino County is at rest, awaiting the trucks that will start delivering grapes tomorrow. The quiet gives me a chance to talk with the notable vintner and his winemaker, Alex MacGregor, about a curious wine that was made three years earlier at Saracina: a 2012 Sauvignon Blanc fermented and matured in prototype terracotta clay barrels—a method, though modernized, that harks back a couple of millennia.

For the past few years, a small confederation of clay experts has been working to develop a new approach to this ancient form of fermentation and storage, giving a long-abandoned material new relevance for contemporary wine. Fetzer and MacGregor are among the few winemakers who have contributed both grapes and time to the research. And today, a couple of those clay experts—sculptor and author John Toki and a fellow ceramicist, Travis McFlynn—are on hand to taste the wine and talk to MacGregor about how the experiment has been going.

Thdesign of these barrels have a long way to go–regarding structural integrity; moveability; and, yes, aesthetically.

Fetzer, a tall and slender man in his 60’s with a full head of silvery hair and a gleaming smile, is easygoing and, as a veteran vintner, is always curious about new developments even if, as in this case, they are intriguingly retro. To advance the project, he’s brought in a series of towering 700-gallon clay fermenters, smaller 200-gallon fermenters, and 60-gallon clay barrels, and has provided the grapes to fill them.

As a wine writer, I taste and compare a lot of vintages, so I was just as curious as Fetzer was to encounter a different approach to a venerable methodology. As he pours the wine, MacGregor warns me not to expect the kind of perfectly conventional sauvignon blanc that’s commonly fermented and matured in stainless steel. “It’s different,” he says, “maybe a little more like Semillon,” referring to another white grape native to Bordeaux.

With one taste, I see what he’s getting at. The wine is flatter, less zesty and bright than Saracina’s normal sauvignon blanc; it’s also earthier, and vaguely resinous. The clay seems to have added a curious ambivalence to its flavors: it muted the wine’s freshness and fruitiness, yet at the same time added an interesting textural character. Toki and McFlynn both seem relatively pleased with it. Fetzer sniffs it, tastes it, smiles slightly, and pronounces it “really weird.” And so it is. It’s a completely different animal, and certainly not a textbook Mendocino sauvignon blanc.

Before turning to the barrels themselves, we taste one other wine that Saracina bottled from this terra cotta series: a 2011 Syrah, something of an experiment from the beginning owing mostly to that year’s unusually cool growing conditions. “It really started out tortured as a Syrah,” Fetzer says, “picked at a very low 19 degrees brix [a measure of the sugar in the grapes]. We had to get it off the vine. It was the leanest, cool-climate Syrah imaginable going into that thing,” he says, pointing to a tall 700-gallon fermenter. “I picked up a funky note on the back end. I thought the bouquet was OK.” Then he pauses. “It’s like an ugly kid,” he says. “You look at it… and you gotta like it.”


John Toki, a sculptor and highly regarded ceramics expert, is having a blast figuring out the technical challenges in clay wine barrels. One of his pleasures in this venture is visiting the factory at Mission Clay in Phoenix Arizona, the storied clay pipe manufacturing plant that is making the clay wine barrel prototypes.

There is a reason that stainless steel and glass have largely replaced clay as wine containers. Those two materials are flavor-neutral; plus, they prevent oxidation. Oak barrels, by contrast, allow wine to go through a slight micro-oxygenation; plus, when new, the oak can impart fashionable woody flavors. At this point, virtually every tool in a modern winery is specifically designed to work with steel tanks and oak barrels. I’m talking about the racks that allow barrels to be stacked 30 feet high, the attachments that help fill them, the tools that clean them, and the pumps that move the wine from one vessel to another.

So why on earth would anyone want to re-visit a vessel made of clay, which is notoriously heavy, breakable, and which some people feel imparts an unpleasantly earthy flavor?

For one thing, aging wine in clay enjoys a long and romantic history, which can lead to a useful cult following. Wine was made and transported in clay “amphorae” for thousands of years before the advent of wooden barrels, and now steel and concrete tanks. That simple fact offers a taste of authenticity not otherwise possible, even with today’s finest French wines. Even today, some winemakers still make small-production wine in traditional clay amphorae buried to their necks in sand or earth.

The tall, conical shape of traditional amphorae can make them difficult to clean, but they do offer natural temperature control during fermentation. Indeed, several wines made in clay outside the U.S. have already grown popular for this very reason. There are, for example, some clay-born white wines made by Josko Gravner and his daughter Mateja near Italy’s Slovenian border; and some ‘Pithos’ reds and whites from Azienda Agricola COS in Sicily.

These are fascinating, unusual, and very fine wines, but they are purely artisanal, small-batch products. What John Toki and McFlynn want to do is different. With the help of Bryan Vansell of Mission Clay, a manufacturer of municipal clay pipes out of Phoenix, Arizona, this cabal of clay enthusiasts is hoping to make wine, with some attractive new flavors, in commercial quantities.

As it turns out, there are some interesting reasons why this team might be onto something.

But first, let’s consider their other challenges. In recent years, large concrete egg-shaped fermenters have made a trendy comeback in high-end winemaking circles. Concrete might sound unromantic, but in some cases it does increase the expressiveness of a wine. And results so far suggest that winemakers appreciate their natural temperature control, the mineral flavors they may impart, and the micro-oxidation effect of their natural “porosity.” Terra cotta possesses similar qualities, due to its own porosity and heat-controlling mass.

Every tool in a modern winery is specifically designed to work with steel tanks and barrels, which poses challenges for introducing a new system like terra cotta.

Then there’s the difficulty of just keeping these barrels properly sealed. The prototype barrels from Mission Clay are made from cylindrical, industrial terra cotta pipe segments with pressed clay ‘heads’ sealed on the ends. And right now, the heads leak and seem insecure compared to oak barrels. When MacGregor filled a clay barrel with a pump at a pressure of 17 pounds per square inch, he was terrified the pressure might blow the head off of the barrel.

What this cabal of clay enthusiasts want to do is different. With the help of a manufacturer of municipal clay pipes they are hoping to make wine, with some attractive new flavors, in commercial quantities.

The clay barrels are also heavier and more difficult to move, and if you drop them, they will certainly break. Without a wooden barrel’s traditional tapering shape, there is more oxygen at the top so they also require more frequent topping off. Toki says a new, curved mold is in the works, but even that is not quite enough to keep the wine in place. All of the racks used to stack barrels at the winery are designed to work with oak barrels, not these heavy clay tubes.

Right now, the terra cotta barrels also “weep,” which means that small amounts of wine seep through the clay. This causes blooms of bacteria and wild yeast to form on the outside of the vessels. As a result, the barrels not only lose significant amounts of valuable wine, they also create an unsanitary environment—an intolerable condition for the curator of a contemporary winery. A proper glaze could potentially solve the weeping problem, but that solution would spawn yet another set of consequences: decreased breathability of the clay, and a reduction in the flavor that unsealed clay imparts. While some of those earthy flavors are a pleasant surprise, others obviously will not be missed.

And the threat of a loamy taste is not the only issue. When clay barrels are unglazed, the wine living in them absorbs more than the earth’s flavors—it also absorbs its metals. Earlier this year, there were reports of arsenic turning up in wine, and MacGregor wanted to be sure that arsenic and other potentially toxic metals don’t leach into wines made in terra cotta. So he tried something that, from all indications, no other wineries experimenting with clay have yet done: he tested some wine with different levels of alcohol and acid in small clay barrels and ran a series of lab tests. The tests did indeed find trace amounts of several metals, including arsenic. But the levels were well below government health limits (some of the wine was even lower, Vansell says, than what labs find in our water supplies.)

Clay pipes can last hundreds if not thousands of years. And in the 1920s, the material was such a mainstay of city infrastructure that there were 65 clay pipe manufacturers in Ohio alone. By the 1970s, city managers had moved toward plastic PVC piping, which can degrade but is less costly (at least in the short term). Today, only 4 clay pipe manufacturing operations remain in the U.S. One of them is Mission Clay in Phoenix, Ariz., which is now looking to the wine industry as a potential new market. For more on this issue, see our sidebar, ‘How our cities got seduced by plastic’

By the laws of physics, whatever moves out of a material can move back into it. And that seems to be the case with clay. As the wine continues maturing, the metals levels have tended to diminish, apparently due to clay’s unusual properties of absorbency. “The clay gives some to the wine, and it also pulls them back out,” says Vansell. Yet this capacity of absorbency raises some very tasty possibilities.


Almost since the discovery of fire, people have used clay to create vessels for cooking. In fact, no other material threatened clay’s monopoly in cuisine until metal foundries discovered stainless steel and other ways to stabilize the potentially toxic properties of metal. Even when fancy metal pots were created, cooks throughout the world remained loyal to clay—for a host of important reasons that have generally been misunderstood. (For a glimpse at the culinary science behind those reasons, see “The Clay Mystique” in our Spring issue.) The aspects of this science potentially related to wine go like this: When a dish is cooked in clay, cooks believe the pot’s pores retain minute particles that create some of that dish’s flavor; when the pot heats up again for each new dish, the clay returns wisps of those old flavors, bringing each new meal what one chef calls the “memory” of all the hundreds of meals that preceded it. Could clay do the same for wine?

When a dish is cooked in clay, cooks believe the clay brings each new meal what one chef calls the “memory” of all the hundreds of meals that preceded it. Could clay do the same for wine?

Vansell certainly hopes so. Once these giant fermenters and barrels have taken on some age, Vansell hopes succeeding vintages might get “these flavor bursts that begin to accumulate in the pores of the clay.” At this point, the Saracina experiment is still too young to gauge whether this might happen. And for some reason, the Saracina team seems intent on figuring all this out themselves, despite the centuries of experience in Old World countries with vessels of this type. All of which led me to ask MacGregor if it felt like they were trying to re-invent the wheel. “Sorta,” he replied, “but heck the guy [Vansell] owns a clay company and has an MFA [a masters degree in Fine Arts], so why not give it a shot?”

Regardless of what happens on the taste front, clay does have one big advantage over all of its competitors: environmental responsibility. With any production materials these days, questions about reusability and sustainability are constant, and getting more urgent every day. And as wine’s global popularity has increased, there has been a parallel rise in demand for the highest quality oak from France, America, Hungary, and elsewhere. Unfortunately, the very best oak comes from cool climates and has a tight grain, which occurs only when a tree is allowed to grow slowly. So massive expansions of supply are, undoubtedly, limited.

Not coincidentally, the price of good barrels has increased steadily over the past 20 years. While a well cared-for oak barrel can potentially be used for decades, if a winemaker wants a certain amount of oak flavor, wooden barrels have a useful life of only a few years. “By the third year, they get cut in half for planters,” Vansell says.


Thhope with clay wine barrels is that they will behave somewhat like clay cooking pots–accumulating layers of flavor from each batch of ingredients they hold; and then returning the “memory” of those tastes to each new arrival.

Later, over lunch, we taste that 2011 Syrah, the one made and matured in clay. MacGregor, the winemaker, still isn’t happy with it. He believes it developed some off-putting oxidation flaws in the barrel, but those faults don’t seem apparent to me. I tried a fresh bottle a few weeks later and found it fine again. The wine shows brightness and spice, characteristic of cool-climate Syrah. But my tastings were far from blind. I knew it was picked at a stage of low sugar, and is only 12.5% alcohol, which leads me to believe that the clay may have contributed what wine experts call “bass notes,” and even some umami flavors that the wine otherwise might have lacked. In other words, this is one wine that might well be better for the clay experience.

It should be noted that these qualities did not last long; in contrast to some wines, which retain and sometimes even improve their character a few days after being opened, both of Saracina’s clay-aged wines went flat quite quickly, even when re-corked with a vacuum seal. In all fairness, though, these weaknesses have little if anything to do with the vessels the wine is aged in, and more to do with the grapes, vines, and soil they come from.

At wine tastings, however, all wines are typically tasted fresh off the cork. So longevity of character is never evaluated. As a result, when John Fetzer tasted his wines, he was impressed with the red. “I was actually proud of the Syrah,” he says. “I wasn’t sure how people in the tasting room would receive it. Nine out of ten people loved it. Of all of the wines we were serving, this was their second favorite.”

The Syrah gets McFlynn’s vote too, especially after getting a chance to subject it to some field testing. He recently opened some bottles at a dinner party hosted by a “heavy-hitting art philanthropist” and a top local chef in San Francisco’s newly hip Dogpatch district. The party featured a variety of wines, yet McFlynn says that “the wines that were gone first were the ones made in clay.” McGregor is skeptical. “They’re just cool hipsters, that’s why!” he says. But McFlynn, a ceramicist to star chefs, understands the marketing appeal of a good story. “Between the label [designed by fellow ceramic artist Jun Kaneko], the story behind it, and the wine itself, a lot of people were blown away,” he says. McGregor just smiles. “I think you need all three,” he says.

They’re both right. In the crowded world of wine, a good story can make a bottle really stand out. And for many people, a good label, a few interesting flavors, and a great story is all it takes to add some romance to what’s in your glass.


For Vansell, there is an urgency to this experiment that extends far beyond some good wine. More and more of the pipes that run underneath our cities are not made of clay anymore; they’re made of a less expensive material: PVC plastic. That change has shrunk the once-formidable clay pipe industry to a handful of struggling manufacturers. (While the plastic pipes have saved cities some money in the short term, they tend to carry some long-term costs. For more on this point, see our sidebar, “How our cities got seduced by plastic.”)

Vansell fully realizes that, even if the Saracina experiment succeeds, his opportunities in the wine barrel market are limited. “We don’t fantasize that clay would ever replace the qualities of oak,” he says. But if commercial interest arises, he’s got his story down. “We do believe,” he wrote in an email, “that a completely natural product (clay), in huge abundance, renewing itself as we speak (geology), that is sustainable (no tree cutting), offering continued use year after year… [with] a unique flavor and a truly fascinating story, will be of interest to wineries and their patrons.”

The risk is that unglazed clay barrels won’t hold the wines terribly well, but will instead “weep,” like these, which would lose valuable grape juices. MacGregor has already been surprised by how often he’s had to “top off” his clay barrels during maturation.

But all these design challenges are not simple. After all, making wine in clay vessels was quite well established by the time oak barrels came around, and the industry changed to oak for good reason. “The Celts taught the Gauls how to make a real barrel that you could roll up a plank,” says MacGregor, “with a bilge in it where the lees can settle properly, with a hole drilled at the top so you can get the wine out without bashing in the clay head the way the Romans did. I want something in clay that’s a little of both, that you can use in a winery and that you can pick up and move if you have to.”

“Those,” says MacGregor, pointing to a clay barrel, “weigh four hundred pounds.” But they’re a lot less expensive, right? MacGregor pauses, relishing the explanation he’s about to deliver. “A four-year, air-cured American oak barrel goes for $550 to $600,” he says. “A French barrel from a top cooper can run up to $1,200, and that’s with a favorable exchange rate. Now that clay barrel there… I would say, up to this point, it’s cost us about $200,000 in R&D. We figured we’d have to sell the wine for around a thousand bucks a bottle.” Everyone bursts out laughing.

For more on the subject…

In the Eastern European country of Georgia, village craftsmen still make giant clay wine vessels the same they’ve done for hundreds of years. Watch them in this video.

BK Wine Magazine, an online magazine, reviews the efforts of a number of producers in continental Europe who are using clay. “Some of them deserve the attention they get,” their writer concludes.

Wines & Vines, based in San Rafael, Calif., covers the efforts of Saracina and other wineries in this story.

The Telegraph’s wine columnist, Victoria Moore, reports on the movement and recommends a few specific wines that are available from U.K. sources (or at least were in March, 2015, when this article was published).

More stories from this issue:

Mezcal’s Dance with Extinction

Rum’s Revenge

The Revival of Nero’s Wine

Latest content:

Watch: “The Tools of an Uilleann Pipe-Maker”

Rewilding Your Yard, with Dr. Doug Tallamy

Western-Wear Designer ‘Jukebox Mama’ Paints with Thread

Back To Top