Myth Buster

The Truth About Gluten-Free Wine

When producers promote their wines as gluten-free, what are they really selling?

Felicity Carter By October 18, 2021
Illustration by Pete Ryan.

As a toddler, Justin Howard-Sneyd was struck by a mysterious and life-threatening illness.

“I had a pot belly and little stick arms, and my flesh was hanging off like jelly,” he says. “No one knew what the problem was.”

One pediatrician suggested that gluten could be causing his symptoms. After a biopsy that Howard-Sneyd describes as “one of the most horrible experiences of my life,” the diagnosis was confirmed: celiac disease. It’s a dangerous immune disorder triggered by gluten, a protein found in grains like wheat and rye. Unchecked, celiac disease will damage the gut.

So Howard-Sneyd should be the perfect customer for the gluten-free wines now appearing on the shelves. Like Fresh Vine, a brand founded by celebrities Julianne Hough and Nina Dobrev and launched earlier this year.

“It’s not very known that wines are not gluten-free most of the time,” Dobrev told the Hollywood Reporter.

Except that Howard-Sneyd already drinks plenty of wine. It’s a big part of his life: not only is he a Master of Wine, whose resumé includes wine buying, wine retail, and wine consulting, but he also makes wine at his own domain in the south of France

So what gives? If wine has gluten in it, how can he possibly drink it?

The problem with gluten

Gastroenterologist Professor David Sanders of the UK’s University of Sheffield is one of the world’s leading researchers into the impact of gluten on the digestive system. He says that while around 1% of the population has celiac disease, many are undiagnosed. “Historically we’ve thought that it was predominantly a disease of Western societies,” he says. “But now, as places like China and the Indian sub-continent are adopting Western diets and are moving away from their rice-based culture, they too are seeing celiac diseases in an increasing number.”

Untreated, the disease not only attacks the lining of the digestive tract, but can lead to other serious conditions, like malnutrition, infertility and cancer.

Professor David Sanders, gastroenterologist, University of Sheffield. Photo courtesy of David Sanders.

Then there are non-celiac patients who suffer unpleasant gastric symptoms when they eat gluten. Professor Sanders says that while “10% of the population self-report symptoms when they eat gluten, we don’t actually know what that means, and whether that’s a true reflection of a new disorder.” He’s not dismissing it, as he says people who have gluten sensitivity may be suffering something like an allergic reaction. Professor Sanders emphasizes that anyone who has symptoms should get tested, rather than self-diagnosing, and that “you should not be on a gluten-free diet for no reason.” 

But for those who must eat gluten-free, what do they need to know about wine?

Unravelling the mystery

There are two points at which gluten could theoretically enter the winemaking process. One is during fining, where a binding agent is used to remove unwanted particles from the wine. As more people embrace vegetarianism, there’s been a flurry of interest in developing plant-based fining agents, like pea and potato proteins. And wheat. The scientific papers documenting this research are circulating freely online.

Which seems to have caused a major misunderstanding — studying wheat fining agents is not the same as using them. When contacted by Pix, a representative of Fresh Vine said that, “Some wines use a process called fining, in which substances are added to the wine to help clarify it, potentially causing gluten contaminants to enter the bottle. Fresh Vine wine is gluten-free, it has no additives.”

Pix surveyed a range of American and international experts, including two university departments, two scientists, and a globe-trotting consultant winemaker, to ask if wheat- or gluten-based fining agents were a real thing. They all answered, no, but a couple didn’t want to say it unequivocally, just in case there was a rogue winemaker out there, fining away with a wheat-based agent. 

Ludwig Pasch, from Germany’s renowned Geisenheim University, told Pix that while he could only speak for European winemakers, “only pea protein and potato protein are actually used in practice.” He went on, “Wheat protein is approved, but is not currently used.”

Even if it’s approved, it can only be used if a winemaker can get hold of it. A phone call to Scott Laboratories in California, one of the world’s biggest winemaking supply companies, revealed that none of their products use wheat or gluten. “Why would you?” said the agent on the fining hotline, sounding scandalized by the prospect. “People are allergic to it.” 

And, indeed, a dive into their catalog did not reveal a single product containing “cereals containing gluten.”

But fining is only one potential point of entry into wine. There’s another one as well.

The barrel situation

Coopers sometimes use a flour paste to seal barrels; as the granules swell, they form a tight seal between the barrel and the head. While coopers do their best to stop flour getting into the barrel, it’s inevitable that some will. But how much?

Professor Sanders says that 20 years ago, the recommendation was that celiac sufferers should stick to foods with less than 200 parts per million gluten. “Then it became 50. Now it’s 20.” As of 2013, food makers in the U.S. can call their products gluten-free if they contain less than 20 ppm.

Christropher Hansen, general manager of Seguin Moreau Napa Cooperage, told Pix that the total amount of flour involved is about one ounce, mixed with an equal amount of water. The paste is applied to the groove where the head sits. “The barrels are filled with some hot water for testing, so at last inspection there is no visible flour inside the barrels.”

Greg Hirson, vice president of Cork Supply USA, which includes barrel maker Tonnellerie Ô, says that even if all the protein in flour was gluten, which it isn’t, and even if every bit of the flour ended up in the barrel, which it doesn’t, there would be a maximum of 5 ppm in the entire barrel, with a typical barrel holding 225 liters, or 60 gallons.

“But that’s basically impossible,” he says. “You can’t have 100% of that flour transfer into the wine or the barrel would leak.”

A study from 2012 had already suggested “that wine appears to be gluten free” but, in 2020, Hirson decided lockdown was the perfect time to find out for himself. The company predicted that a maximum of 25% of 1 ppm could potentially get into the barrel. To find out if they were right, they tested five barrels in two different wineries. “There was no gluten detected,” he says. 

Given all of this, it’s fair to say that some producers may genuinely be confused about whether there’s gluten in wine or not. It’s also possible that labeling a wine as gluten-free is just a cynical attempt to cash in on wellness trends.

Howard-Sneyd, for one, believes that calling wine gluten-free is co-opting a serious illness. “You say a wine’s gluten-free and immediately everyone assumes that other wines are not gluten-free,” he says. “And then they panic about not being able to drink wine. It’s completely pointless and just makes everyone else put gluten-free on their label.”

There is something in wine that can cause gut issues — alcohol. But gluten? That’s a myth.