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Adhering to a strict gluten-free diet can be stressful and time-consuming. Whether driven by celiac disease or non-celiac gluten sensitivity, the ability to read labels is an indispensable skill. But although most food products are required to include detailed nutritional and ingredient information on their labels, many alcoholic beverages are a different story.
Sure, we know beer—famously a cereal grain-based beverage—is off the table for gluten-free folk, but what about wine? We asked industry experts if wine is gluten-free, so those with dietary restrictions can imbibe worry-free.
Is Wine Gluten-Free?
According to the FDA, in order for a product to be considered gluten-free, it must contain less than 20 parts per million of gluten. Products that meet this legal standard contain less than 0.002% gluten.
So, does wine meet these standards? Tricia Thompson, M.S., R.D., is the founder of the Gluten Free Watchdog, an organization that tests consumer products through Bia Diagnostics, a food testing lab in Vermont, to determine levels of potential gluten. Her answer? Yes, but with a caveat. (More on that below.) Wine has always been considered naturally gluten-free, she points out, since the ingredients used in fermentation (grapes and yeast) are naturally gluten-free ingredients.
The Risk of Cross-Contamination
But, it may not be so simple. Though wine’s ingredients are 100% gluten-free, there is always the risk of cross-contamination, which is the process by which bacteria or other microorganisms are inadvertently transferred from one surface or substance to another, sometimes with harmful effects.
Some winemaking processes could potentially unintentionally introduce gluten to the mix, like fining, which is the process of filtering out unwanted particles that may cause a wine to look hazy or taste bitter. Strict gluten-free adherents may want to ensure that fining agents are gluten-free.
From a cross-contamination standpoint, that may be difficult to do, especially because most countries have different regulations when it comes to wine production. The Alcohol and Tobacco Tax and Trade Bureau reports that approved fining agents in the United States include chitosan (a type of sugar) and pea protein. Other countries, like Australia, tend to use ingredients like egg whites and gelatin.
The good news for gluten-free folk? None of these additives contain gluten, in theory. (Several, however—including gelatin, isinglass and egg whites—contain animal products, which means they may not be suitable for vegetarian or vegan wine drinkers.)
Here’s the rub: There’s no way to say for sure that a wine was or wasn’t made with a fining agent cross-contaminated with gluten. But, Thompson notes, “In the U.S., The Alcohol and Tobacco Tax and Trade Bureau which oversees the industry, provides a list of materials authorized for the clarifying, filtering or purifying treatment of wines.” She notes that no gluten-containing ingredients are listed, and it’s reasonable to assume that most bottles made with fining agents are gluten-free.
Another risk factor to consider is that some wines are fermented or aged in oak barrels. This winemaking technique gives the finished product a soft, silky texture. Traditionally, the barrel heads (the round tops) were sealed with a gluten-rich, wheat-based paste, which theoretically presents a risk of gluten contamination. Red wines such as Cabernet Sauvignon, Merlot and Zinfandel tend to age longer in these oak barrels and therefore may run a greater risk of being contaminated with gluten. That said, the risk is still very minimal.
However, it’s clearly an issue on the minds of people concerned with gluten contamination. A representative from Independent Stave Company, the largest barrel maker worldwide notes, “In 2019 we switched from wheat flour and transitioned to gluten-free buckwheat flour and paraffin to seal heads.”
