Is Wine Gluten Free?

By Chris Penwarden https://gothamvine.wordpress.com/

As a certified wine geek, I get asked a lot of questions via social media about wines that friends are about to drink. Usually they are faced with a daunting wine list in a posh restaurant and need some friendly advice on how to navigate it. However, I was asked a question recently that had me stumped: is wine gluten free? 

My good friend Aileen Markey from Unglu-d had heard that wine barrels are sometimes sealed with a wheat paste, which of course would mean that the wine stored in such an aging vessel would have contact with gluten. This would be bad news for Aileen, a fan of rich, barrel-aged Malbec’s from Argentina.

Well, having done a bit of research I can reassure you all that wine is gluten-free, certainly if your definition corresponds with the United States’ FDA (Food and Drug Administration) threshold of 20 parts per million. 

As Esther Mobley explains in a Wine Spectator article published in 2013, wheat flour paste was a traditional sealant, but many modern coopers use wax substitutes. But, even if wheat paste were to be used, ‘finished barrels, no matter their sealant, are rinsed and sanitized with sulfur dioxide before leaving the cooperage.’ According to Phil Burton, owner of Barrel Builders in Napa, any paste residue would glow green when inspected with a flashlight, necessitating a re-clean to avoid adulteration. Mobley concludes that, ‘In other words, the amount of this paste that ultimately penetrates the wine is probably negligible.’

As further evidence, Mobley sites Master Sommelier Tricia Thompson’s tests on wheat-paste-sealed barrel-aged wines as founder of GlutenFreeWatchdog.org. Thompson reported readings between 5 and 10 parts, far below the FDA regulations.

The only other way gluten could be introduced would be through its use as a fining agent, the purpose of which would be to eradicate haziness in the finished wine. But, as Mobley says, ‘these gluten-based fining agents are very rarely used nowadays, and as with the paste, the amount that could appear in the finished wine is miniscule. A 2011 study in the Journal of Agricultural and Food Chemistry found that wines fined with a gluten-based agent ultimately contain either very little gluten or no gluten at all.’

In a follow up to Mobley’s 2013 piece, Wine Spectator published the conveniently titled Is Wine Gluten Free? in November 2018. In the article Lexi Williams confirms that gluten-based fining agents are so rare that ‘two enologists interviewed for this story were unaware that gluten-containing fining agents even existed.’ A clay-like substance, Bentonite, is the fining agent of choice these days, having replaced the rather unpalatable sounding gelatins, ox bloods and egg whites of a by-gone era.

The take home message? If you are a consumer of Gluten-Free products, as defined by the FDA, you can safely imbibe wines that have been aged in an oak barrel. Bordeaux reds, Malbecs and oaky Chardonnays should not be off the table.

However, if you’re one of the unfortunate few that finds you are particularly sensitive to gluten, even at levels below the labelling thresholds, I would stick to wines fermented or aged in clay and stainless steel. Luckily, this accounts for most of the white wines on the market and certainly many fresh, fruity, earlier-drinking styles of red wine. 

Hopefully in the future wine labels will have more user-friendly advice that can helps those with dietary sensitivities such as those with gluten intolerance. In the meantime, ask in your local store or the staff at your favourite restaurant to recommend wines that are aged without wood. Or, if you suffer ill effects from a particular style of wine, keep a note to help someone pick the perfect happy bottle for you.

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