Why distillation is compatible with a gluten-free diet

Why distillation is compatible with a gluten-free diet

In Honor of Celiac Disease Awareness Month, Gluten Free Watchdog is writing a series of articles (the goal is one per day during the month of May) related to the gluten-free diet–currently the ONLY treatment for celiac disease.

Post (#24)…

Astute readers of gluten-free labeling rules may have noticed that the FDA and the TTB treat distilled alcohol differently.

On the one hand, the FDA allows distilled alcohol and distilled vinegar as ingredients in foods labeled gluten-free regardless of the starting material (e.g., vanilla extract containing distilled alcohol, catsup containing distilled vinegar). On the other hand, the beverage “distilled alcohol” is not allowed by the TTB to be labeled gluten-free if the starting material is wheat, barley, or rye.


The FDA views distilled alcohol and distilled vinegar made using distilled alcohol to be ingredients “processed to remove gluten.”

In a Q&A for the FDA’s proposed rule for gluten-free labeling of fermented or hydrolyzed foods, FDA writes:

“Can distilled foods made from ingredients derived from gluten-containing grains be labeled as “gluten-free”?

Yes.  Since proper distillation is capable of removing all proteins, including gluten, it would be considered as a “process to remove gluten.”  Thus, an ingredient that is derived from a gluten containing grain that has been properly distilled would be allowed to be used in a food bearing the “gluten-free” claim since the ingredient would meet the requirements of 21 CFR 101.91.”

The TTB takes a slightly different approach. Distilled alcohols can be labeled “processed to remove gluten” as long as a second statement also is included on the label:

“This product was distilled from grains containing gluten, which removed some or all of the gluten. The gluten content of this product cannot be verified, and this product may contain gluten.”

If this is confusing to you, the following excerpt from The Gluten-Free Nutrition Guide (Tricia Thompson, McGraw-Hill, 2008) may help:

“Alcoholic beverages are either fermented or distilled. Fermented and distilled beverages are made by first converting starch or sugar from a food source (for example, grapes, wheat, or potato) to alcohol, using yeast. With fermented beverages, such as beer, the liquid removed from the mash (the mixture of starting materials) is boiled. If a gluten-containing grain is one of the food sources used to make the mash, the liquid removed from the mash is not gluten-free. With distilled beverages, such as vodka, the liquid removed from the mash is not only boiled but also distilled. Distillation is used to increase the alcohol content of the beverage. When the liquid is boiled, the vapor is “captured” and cooled. The resulting liquid is called the distillate. Distillation separates substances that are volatile (meaning they vaporize) from less volatile substances. Protein is not volatile and does not vaporize. Consequently, even if wheat, barley, or rye was used to make a distilled alcoholic beverage, gluten-containing proteins will not be found in the final distillate.”

Tomorrow’s post: Nutritional Quality of the Gluten-Free Diet

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Comments (29)

  • Bonnie Reply

    Hi Tricia, Does the molecular structure of the “distilled” beverages, and/or the question of what quantifies 20ppm prevent them from being tested for gluten using the R5 ELISA tests?

    May 24, 2017 at 3:23 pm
    • Tricia Thompson Reply

      While the TTB requires that all manufacturers of alcoholic beverages labeled gluten-free test their products using the competitive R5 ELISA (which detects hydrolyzed gluten) there are concerns among some (including the FDA and TTB) that this test is more qualitative than quantitative. It is difficult to translate gluten protein fragments into ppm intact gluten protein.

      May 24, 2017 at 3:44 pm
      • Bonnie Reply

        Thank you for this answer.

        May 24, 2017 at 4:06 pm
  • Randall Reply

    In the last paragraph:
    Would you the consider Whisky and Gin also gluten free, based on these same ideas?

    May 25, 2017 at 1:11 pm
  • Tyler Webb Reply

    This has always been a conundrum for me. I was made sick from a major branded bourbon and upon inquiry was told by a company representative that the bourbon was tested and did contain gluten. Disturbing as I was under the impression to be labeled a bourbon the mash required a specific ratio of ingredients and aging in a new charred oak barrel with no additional additives. They would not tell me why gluten was found only that testing confirmed. I guessed either coloring agents or considering the blend maybe some of the distillate was of poor quality and run at a very fast and high temp. Anyway I guess I have no real question other than when it comes to distilled alcohol there still remains some questions

    May 25, 2017 at 5:09 pm
    • Tricia Thompson Reply

      Thanks, Tyler. Pure distilled alcohol from a proper distillation will not contain gluten protein. That said, IF this bourbon truly contains gluten (I would love to chat with the manufacturer if you would like to share the name privately) it is likely coming from something added after distillation. It is unlikely to be coming from the barrels. As you state, new oak barrels are supposed to be used for most bourbon varieties. Even if the oak barrel is used it is unlikely that any wheat paste is getting into the bourbon. See our testing of wines at https://www.glutenfreewatchdog.org/news/gluten-content-of-wine-aged-in-oak-barrels-sealed-with-wheat-paste/

      May 25, 2017 at 5:32 pm
      • Connor Scott Reply


        I’ve actually read that some whisky/bourbon manufacturers will add some of the mash back into the distillate alcohol to enhance the flavor, and only filter/otherwise remove it (not by distillation) once it has “steeped”.

        An analytical chemist on Reddit had interesting points on distillation of gluten-containing alcohols, citing specifically that distillation may not be sure-fire due to prolamines that are carried over: http://bit.ly/2uMyUEK

        As a subscriber, I’d be very interested to see the result of ELISA assays on some common whiskys, vodkas (that aren’t made from GF grains) and other distilled alcohols from gluten-containing grains. I find that certain brands of distilled whisky elicit a celiac reaction from me, while others do not. Perhaps we’re overlooking something, as I’ve (at least anecdotally) seen a lot of mixed reviews about certain liquors.

        Those 50mL airline bottles shouldn’t break the bank for something like this 🙂

        August 17, 2017 at 6:54 pm
      • Connor Scott Reply

        I’m not able to edit my last comment, but here’s another link with some great insight regarding distillation and contamination: http://bit.ly/2uUxPqD

        August 17, 2017 at 7:08 pm
      • Tyler Webb Reply

        Hey Tricia,

        Jeffersons was the brand. Kind of a nationwide mid level blend


        August 18, 2017 at 5:46 pm
        • Tricia Thompson Reply

          Hmmm. I wonder if this is simply because the TTB will not allow alcohol to be labeled gluten-free if the starting material is wheat, barley, or rye. But they told you they tested?? I will look into this next week.

          August 18, 2017 at 5:51 pm
          • Tyler

            Yes. They told me the end product had been tested. I brought up all the questions outlined above to radio silence. At least they were kind enough to tell me it did if not why.

            August 18, 2017 at 10:06 pm
        • Tricia Thompson Reply

          Hi Tyler, Can you please let me know the specific Jefferson’s product that made you sick? The product list is available here https://jeffersonsbourbon.com/products/

          October 12, 2017 at 5:53 pm
          • Tyler

            Hi Tricia,

            It was the ‘Jefferson’s Very Small Batch’. I believe that is their least expensive and standard blend.

            October 12, 2017 at 6:45 pm
          • Tricia Thompson

            Thank you. I’m hoping to test this product.

            October 12, 2017 at 7:01 pm
  • David Reply


    I enjoy drinking whiskey and usually drink barrel proof/cask strength bourbons and ryes. Since they are barrel proof/cask strength the distilled whiskey “should” go from the barrel to the bottle. So no chance anything could be added to the distillate before bottling.

    I would still like to test my bottles. Which test kit can I get to test my whiskey? Is it available on Amazon.

    December 15, 2017 at 11:01 pm
    • Tricia Thompson Reply

      Hi David, Both a sandwich ELISA and a competitive ELISA should be used. None of the commercially available consumer test kits are appropriate for testing alcohol. You can contact Bia Diagnostics or FARRP regarding testing.

      December 18, 2017 at 4:04 pm
  • Peggy Reply

    Hello Tricia, Every well trusted Celiac site I read says the same about distilled alcohol. That it is safe for me, as a Celiac, to consume. That the distillation process makes it GF. Because of these trusted sites, I assumed I could drink Rum (not flavored) and I kept getting DH. It was a hot summer so I made cold drinks for myself and husband about 4 times a week. One day just as I began to add the rum, something just told me to google it, so I did. FYI Bacardi Rum Silver has gluten added back into it AFTER the distillation process. This is a very well known and often purchased brand. Reading some posts above (May 24 and 25 2017) sounds like this is not the only distilled alcohol that gets a gluten mash of some sort added back after it’s been made GF. I know it is far too big of a job to find out exactly which companies add back, but I wish SO VERY much that trusted GF sites would disclosed this. I trusted and got burned, so now , when I am doing research, I’m not sure what to believe. Please know I don’t mean to sound disrespectful, as I really appreciate all you do, but for some reason when it comes to alcohol, sites such as yours seem to either be in denial themselves or …well I don’t even know why they would not warn us. When we with Celiac are having cc symptoms, we try so hard to figure out why, but if we are getting cc from something that we are told is safe….well you can imagine how much MORE frustration and discouragement this disease can cause. All when it could have been avoided by a statement on sites such as yours. If I had my wish, every site that says distilled spirits are gluten free, they would add (immediately and in same size or larger lettering) to always check with manufacturer to see if ANYTHING has been added after product was distilled. Sure would’ve saved me some grief! I receive the Gluten Free and More magazine, wrote to them requesting they change their misleading statement that is in every magazine. They quoted trusted sites to me saying I was incorrect, but eventually they added “unless gluten containing flavoring is added after distillation”. I was glad they added that, however most of us think of flavoring as ‘lime’ or ‘strawberry’ etc., so we are clueless that a whiskey or rum or…. may have added a ‘flavor’ back after distillation, as it does not say that on the label. The Bacardi rum I used was just plain ol’ rum. My goal is to help other Celiac’s educate themselves. The doctors in my area can barely spell Celiac, so I’ve have had to learn everything about it via my own research. I’ve figured out many others are having to do the same. I hope to hear back from you, thank you for ‘listening’.

    February 24, 2018 at 7:18 pm
    • Tricia Thompson Reply

      Hi Peggy, We are currently in the process of testing 14 distilled alcohols for gluten, including Bicardi rum. A full report will be posted for subscribers to GFWD. We will be covering all the TTB definitions of the various alcohols, including what can and can not be added to various alcohols (and when). There does however appear to be some confusion. Bicardi in the past has made a MALT beverage called Bicardi Silver. Unfortunately, when searching under Bicardi Silver, Bicardi Premium comes up. Bicardi Premium is a white rum. It is not a malt beverage.

      February 28, 2018 at 4:01 pm
  • Darryl Wooldridge Reply

    Does the gluten elimination, proteins, and all else happen to high end spirits?

    May 10, 2018 at 6:41 pm
    • Tricia Thompson Reply

      Pure distilled spirits, such as vodka and gin do not contain any gluten protein (assuming proper distillation).

      May 14, 2018 at 6:58 pm
  • J W H Reply

    Everyone should remember that the effect of distillation is a sliding scale, not a yes/no situation. All distillates are subject to multiple passes through the still to get the proof required by almost every production law in every country (80 proof, or 40%ABV). One pass through a still is not enough to strip the “low wines” of the original liquid and raise the proof to 40%abv, especially in a potstill. Even a column still emulates the effect of multiple passes. That said, each time you do a run, less of the original content of the mash is left behind (including gluten). This is why vodka is often clear and has no odor…because there’s not much left besides alcohol (same with gin, to which herbs and spices are distilled along with the spirit). In robust spirits such as bourbon, Scotch, brandy, rum, etc. fewer passes through the still are the norm, leaving behind more of the original material – which in some cases may contain gluten if the glutenous grains were used in the mash. While it is improbable that distillation to higher than 80 proof will leave any gluten-like proteins behind, it is possible, especially if using a potstill (although most commercial distilleries use column stills. By law Bourbon must be 51% corn, but that leaves a lot of glutenous grain left to make up the rest of the bill. You must also use brand new barrels for Bourbon by law, and while the law prohibits coloring to be added to bourbon labeled “straight,” producers can add up to 2.5% caramel color to whiskey (most commercial Scotch makers do this). Much of this hinges on a lack of transparency, where companies hide behind loosely codified rules and lots of costly marketing ploys. Dozens of whiskey labels these days are all made by the same distillery, don’t forget.

    March 11, 2019 at 6:11 pm
  • michellemedrano1969@yahoo.com Reply

    Is coors hard seltzer glutin free

    November 20, 2020 at 5:06 pm
    • Tricia Thompson Reply

      Do you have a link to the specific product you are interested in drinking?

      December 2, 2020 at 1:57 pm
  • Darcie Reply

    Also would like to know about the corona hard seltzer’s. I’ve been diagnosed with celiac fir 8 years now, this product is labeled gluten free yet I am experiencing symptoms that it’s not also my dr checked my gliadin levels which were high and is indicating I’m consuming gluten. I drink these everyday 🥴 or I was. It’s so frustrating as things are labeled gf yet they aren’t. So what can I do to ensure a product is truly gluten free?

    December 9, 2020 at 3:35 pm

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