Is there gluten in Cabernet Sauvignon? Navigating Wine on a Gluten-Free Diet

October 8, 2025 •

4 min read

According to the U.S. Food and Drug Administration (FDA), a product can be labeled gluten-free if it contains less than 20 parts per million (ppm) of gluten. This standard is relevant when asking, 'Is there gluten in Cabernet Sauvignon?', since wine, at its core, is naturally gluten-free as it's made from grapes. However, certain steps in the winemaking process raise important considerations for those with celiac disease or gluten sensitivity.

Quick Summary

This article explores the likelihood of gluten in wine, focusing on Cabernet Sauvignon. It explains how potential cross-contamination can occur through fining agents or barrel aging, though modern practices and testing confirm risks are extremely low. It also offers advice on selecting safe wines.

Key Points

Cabernet Sauvignon is naturally gluten-free: As a traditional wine made from grapes, the primary ingredients do not contain gluten.
Trace contamination risk is minimal: Rare and outdated practices like wheat paste barrel seals or gluten-based fining agents are largely no longer used and result in negligible gluten levels, well below the 20 ppm legal limit.
Flavored wines pose a greater risk: Wine coolers and flavored varieties are more likely to contain gluten from additives, so always check labels for these.
Stainless steel is the safest bet: Wines aged in stainless steel vats carry no risk of gluten contamination from the aging process, offering peace of mind for sensitive individuals.
Look for certification and contact wineries: For ultimate certainty, choose wines certified gluten-free or reach out directly to the manufacturer about their production methods.
Modern winemaking minimizes risks: Growing consumer demand for allergen-safe products has pushed the industry toward transparent, gluten-free practices.

The Winemaking Process: How Gluten Could Enter the Equation

Wine production is a fascinating journey that transforms grapes into a complex beverage. The foundational ingredients—grapes and yeast—are inherently gluten-free. The fermentation process, where yeast converts grape sugars into alcohol, does not introduce gluten. However, later steps in the winemaking process, specifically fining and aging, are where trace amounts of gluten could theoretically enter the picture, though this is now very rare.

Fining Agents: Clarifying Agents with Minimal Risk

Fining is a clarification process that removes unwanted particles and sediment to produce a clearer, more stable wine. It involves adding a fining agent that binds to these particles and settles at the bottom of the vat, allowing the clear wine to be siphoned off.

Historically, and very rarely, winemakers might have used wheat-based proteins as a fining agent. However, this practice has largely been replaced due to allergen awareness and the availability of equally effective, gluten-free alternatives. Modern fining agents are typically derived from naturally gluten-free sources, including:

Bentonite clay
Egg whites (albumen)
Gelatin (derived from animal collagen)
Isinglass (fish bladder protein)
Pea protein

Even in the rare event that a wheat-based fining agent was used, studies have shown that the gluten concentration in the finished wine is significantly below the legal limit of 20 ppm. For most individuals, this trace amount would not be a concern, though those with extreme sensitivities should remain cautious.

Oak Barrel Aging and Wheat Paste

Another point of potential, though negligible, cross-contamination is barrel aging. Some winemakers traditionally sealed the heads of oak barrels with a paste made from wheat flour. As the wine ages, a minimal amount of gluten could potentially be absorbed.

However, this practice is now uncommon. Many winemakers have transitioned to modern, gluten-free sealants, such as paraffin or beeswax. Furthermore, even in barrels where wheat paste was used, tests have confirmed that the gluten levels transferred to the wine remain extremely low, typically between 5 and 10 ppm, well below the 20 ppm FDA standard for a gluten-free label.

Making Informed Choices for a Gluten-Free Lifestyle

For someone on a strict gluten-free diet, being informed is the best way to enjoy wine without worry. Fortunately, the vast majority of traditional, unflavored wines, including Cabernet Sauvignon, are safe. The Alcohol and Tobacco Tax and Trade Bureau (TTB) requires winemakers to label products that meet the FDA's criteria, providing additional assurance.

How to Identify a Truly Gluten-Free Wine

Look for certification: Seek out wines that are explicitly labeled or certified as gluten-free.
Stick to traditional wines: Plain red and white wines, without added flavors, are the safest choice. Flavored wines, coolers, or other wine cocktails may contain gluten in their added ingredients, such as barley malt.
Choose stainless steel: For absolute peace of mind, opt for wines fermented and aged in stainless steel tanks, which completely eliminate the barrel-aging risk.
Contact the winery: If you have specific concerns or severe sensitivity, reaching out to the winery directly can provide clarity on their production practices.

Comparison: Oak-Aged vs. Stainless-Steel Aged Wine


Feature	Oak-Aged Wine (e.g., some Cabernet Sauvignon)	Stainless-Steel Aged Wine	Conclusion for Gluten-Sensitive Individuals
Potential Gluten Source	Historically, rare use of wheat paste for barrel sealing.	No gluten risk from aging container.	Minimal risk, but not zero for extremely sensitive individuals.
Current Industry Practice	Modern wineries use gluten-free sealants like wax.	Increasingly common, especially for crisp white wines.	Low risk for modern oak-aged wines; no risk for stainless-steel aged.
Flavor Profile	Adds complex flavors like vanilla, spice, and toast.	Retains the fresh, primary fruit characteristics of the grape.	Neither is inherently better, just different flavor profiles.
Gluten Levels Tested	Tests have shown levels well below 20 ppm.	No gluten detectable.	Both considered legally gluten-free; stainless steel is safer for extreme sensitivity.

The Takeaway for Cabernet Sauvignon Lovers

In almost all cases, a glass of Cabernet Sauvignon is a perfectly safe choice for individuals on a gluten-free diet. The very limited potential for cross-contamination from outdated fining or barrel-sealing methods has become largely irrelevant due to modern winemaking techniques and heightened allergen awareness. By being a savvy consumer—reading labels, choosing traditional varieties, and considering stainless steel options—you can confidently enjoy your wine without worry. For more detailed information, consult the official guide at Beyond Celiac.

Conclusion: Savoring Your Gluten-Free Cabernet

For those adhering to a gluten-free diet, the good news is that traditional wines, including rich red Cabernet Sauvignon, are overwhelmingly safe. The natural fermentation process uses gluten-free ingredients, and historical sources of potential cross-contamination are now rare and produce negligible levels of gluten. By understanding winemaking practices and looking for certified or stainless-steel options, you can make informed choices and continue to enjoy your favorite vintages with confidence. Cheers to delicious, gluten-free wine!

Frequently Asked Questions

Yes. The natural fermentation process of wine does not involve grains containing gluten. The conversion of grape sugars to alcohol is a safe, gluten-free process.

It is highly unlikely. While some fining agents used in the past rarely contained gluten, modern winemaking largely uses gluten-free alternatives like bentonite clay, egg whites, or pea protein. Any residual gluten from these older methods is generally well below the 20 ppm standard.

The risk is very low. Historically, wheat paste was sometimes used to seal barrels, but modern wineries now use gluten-free alternatives like wax. Extensive testing has confirmed that any gluten transfer from this outdated practice is minimal and well within legal gluten-free limits.

Most are safe. As with Cabernet Sauvignon, other traditional red wines like Merlot and Pinot Noir are naturally gluten-free. The risk is the same as any other traditional wine, dependent on specific aging and fining processes.

To be completely certain, look for wines that are explicitly labeled or certified gluten-free. You can also choose wines aged in stainless steel, which eliminates any barrel-related risk. Additionally, for specific brands, you can contact the winery directly for information.

Not necessarily. Wine coolers and cocktails often contain added flavorings, colorings, or malt-based ingredients that can introduce gluten. It is crucial to check the ingredient label on these products.

Not inherently. The potential for risk depends on the specific winemaking process, not the price point. A less expensive wine may be aged in stainless steel, while a premium wine might have been aged in oak. Always check production details or opt for a certified gluten-free brand for peace of mind.