Identifying Hidden Sources of Gluten

By: Danica Loucks – Udi’s New Face of Gluten Free


Perhaps you’re on gluten-free diet and it seems to be working well for you, but every once in awhile you find yourself glutened yet can’t identify the culprit. Unfortunately, this happens to many Celiac and gluten intolerant folks because of hidden sources of gluten in foods that we might assume to be gluten-free. Where may some of these ninja-like gluten offenders be? In Rice Krispies (although there is now a gluten-free version, but look for a clear gluten-free label), salad dressing, soy sauce, chips, soups, candy, medication, ice cream.  Sometimes it can feel like gluten is around every corner.


Verifying the gluten-free status of some products will become a little easier with the recent FDA ruling that demands that products labeled “gluten-free” must contain less than 20 parts per million. That ruling should help clear up at least some products’ gluten-free status.  However, it’s still important to hone your detective eye for hidden or unexpected sources of gluten in order to avoid accidentally purchasing gluten-filled product or consuming gluten while dining out.

So what’s a person to do? Not consume products that aren’t clearly gluten-free until you’ve checked with the manufacturer and then memorize a list of all the “safe” products? Well that might be the safest course of action for people with Celiac or severe reactions to gluten, but for people with a lower gluten sensitivity there are ways that you can keep protect yourself as you navigate shopping and eating.


Know common “hidden” gluten ingredients:

Learn red flag ingredients that you may spot on labels. There are the obvious ones, such as “wheat flour,” that can be hidden in unsuspecting products like licorice candy, chips, and soup. Products that contain wheat should, by law, be labeled as such in bold letters, as it is one of the top eight allergens. However, it seems that not all ingredients that are wheat-derived are labeled, and there are other non-wheat sources of gluten.

Red flag ingredients include:

  • “Barley Malt” or “Malt” – Examples: Rice Krispies, Cornflakes, Lindt Truffles
  • “Soy Sauce” – Contains wheat unless the item is made with gluten-free “Tamari” soy sauce. Also, I used to think that all Tamari-style soy sauce was gluten-free, but recently saw that Kikkoman makes a non-gluten free Tamari soy sauce—that’s a good one to ask your waiter or friend if you’re a dinner guest.
  • Worcestershire Sauce – I’ve found this ingredient to be particularly sneaky as some versions contain gluten and some don’t.  I once had a housemate tell me “Hey, you should eat this chili with us, it’s gluten free,” and then watched him pour a whole bottle of Worcestershire sauce into his bubbling pot. It’s easy for people to not even wonder whether a sauce has gluten in it or not, so this is the kind of ingredient that it might be good to ask about specifically.
  • Wheat, barley and rye in their Latin names: Triticum vulgare (wheat), Hordeum vulgare (barley), Secale cereale (rye), Triticale (cross between wheat and rye), and Triticum spelta (spelt, a wheat variety)
  • Finally, there are several common ingredients whose gluten content is debated or for which there are gluten-free and gluten-filled versions. These include: Dextrin, Maltodextrin, Modified Starch/Modified food starch, Natural Flavor, and Artificial Flavor. Some companies are now labeling whether their products’ food starch comes from corn or wheat, but many remain unlabeled. Dealing with these ingredients may be a matter of avoiding them “just in case” or testing products that have no other signs of gluten on an individual basis.


Know what kinds of unsuspecting foods might have a gluten ingredient:

If you’re like me, you read any label you can get your hands on before putting anything in your mouth. If you don’t read every label, keep in mind the types of products that commonly have hidden gluten (those labels you might want to start reading!): canned soup, salad dressing, chips, ice cream, noodles (yes, some rice or buckwheat noodles have added flour), and pretty much any “snack” food. Conveniently, the foods that you know are the safest—unprocessed foods such as fresh fruits and vegetables—are better for your health anyway!

Know the taste and appearance of gluten ingredients:

Ideally, you’d know whether something contains gluten before it’s sitting in front of you ready to eat, but sometimes miscommunication occurs. I’ve found this kind of mishap common when traveling with a language barrier or where “gluten-free” is not a well-known concept. You may want to “double-check” (ask about specific ingredients that you suspect might be in the food) when something suspicious comes up. I keep an eye out for:

  • Dark-colored and salty sauces (suggests soy sauce might be an ingredient)
  • Thick and/or opaque sauces (may have been thickened using flour/be roux based)
  • Creamy soups (may use flour as a thickener)
  • Foods that appear to have been deep-fried (may have been fried in the same oil as gluten-containing products, may be breaded)


Yes, it often feels like gluten stealthily infiltrates some of the most unexpected places. However, the more you know what to look out for, the more you can sidestep gluten encounters. Read labels. Look up unfamiliar ingredients online. When in doubt, ask a waiter or friend. When he or she has no idea what you’re talking about, remain a patient advocate for your own health and use the encounter as an opportunity to educate others about Celiac disease and gluten intolerance.  Sneaky gluten may be popping up everywhere, but being attentive, having knowledge about obscure gluten-containing ingredients, and communicating with people who are preparing or handling your food are key techniques for avoiding those hidden sources of gluten.


What are some hidden sources of gluten you’ve found?




105 responses to “Identifying Hidden Sources of Gluten”

  1. Jess C. says:

    “caramel color”

  2. Stephanie Simms says:

    Found this website and discovered a couple of the meds I take have or cannot guarantee not to have gluten. Changed brands of those and already can tell a difference.

  3. Tami says:

    Also, I have found gluten in shampoo, conditioner, soap, lotion, cosmetic. things that are absorbed in the skin can cause reactions as well.

  4. Pam says:

    Sweet Baby Ray’s Original BBQ sauce is gluten-free.

  5. Tami says:

    Spices, some use anti-caking agent without listing what it is as it is under 2% they are not required. Also, Chicken with a % of retained solution. the meat counter man researched further to find MSG in the solution. I always read labels even it listed as gluten free because i have found dextrose, maltodextrin.

  6. Mary Mollway says:

    almost all sauces have gluten unless designed otherwise, as it is used as a thickener. Shampoo and conditioner are common hidden culprits as well.

  7. mollyparr says:

    We found out the hard way in Paris that many gelatos have gluten.
    It took us forever to figure out that was the source of the severe reaction !

  8. Mary Mollway says:

    To the reader who posted about Progresso soup. Modified food starch doesn’t usually come from wheat, it is usually corn. So, if a product is labeled gluten free and has MFS, it is prob from corn.

  9. DL says:

    Makes me very sad that corn is in so many products. Some believe that corn is not gluten, but my body begs to differ. Limits my choices big time! : (

  10. Rice Dream is milled with barley, too, so it depends on what level you have to eliminate it too.

  11. Helena says:

    Lea and Perrins Worchestire sauce is only gluten free if it is made in the US, the Canadian brand contains wheat

  12. Lindsey says:

    Barbeque sauce and most all bottled sauces are problematic if not specifically labeled. It’s nearly impossible to find a GF barbeque sauce other than specialty ones. Also, Twizzlers. I didn’t know about Lindt truffles before reading this, but will check my chocolate more carefully in the future.

  13. Julia Radin says:

    Toothpaste, vitamins, and prescription drugs.

  14. Terry says:

    Certain store brands of cake frosting.

  15. Becky says:

    Licorice! ! Has gluten!

    • Lorinda says:

      but modified food starch can come from corn as well. They can’t put gluten free on the label if they use the wheat based kind.

    • Krystal says:

      You have to realize that employee doesnt care because they are a person that hangs labels, they just do as they’re told. Also, modified food starch isn’t necessarily NOT gluten free, it just means theres a chance it’s not because its a vague label. Like carmel color, in US is fine to eat, but out sourced carmel coloring starting to get ify. I say just listen to your body. If it says no to it, don’t eat it again. Also… we ALL know that Gluten free labeling doesn’t mean it’s 100% Gluten free? it’s a certain PPM…

    • Jen says:

      This would mean it is not modified with wheat flour but something else. Just because it says it is modified does not mean it is for sure not gluten free. The company would know the fine details and label appropriately.

  16. Louise A. Johnson says:

    Look at the Progresso soups they claim are Gluten Free. They contain modified food starch. Seriously! I never buy or eat anything that indicates it contains this. I even pointed this out to my local grocery store when I found an employee labeling the shelf with their little GF labels for the Progresso soup. They simply ignored me.

    • Stephanie Simms says:

      Modified food starch is an ingredient made from a variety of starches, mostly corn now.. Modified food starch is gluten free unless it is made from wheat. If modified food starch is made from wheat, “wheat” will appear on the label. Also, more and more companies are listing all sources of modified food starch voluntarily.

    • Lorinda says:

      Melanie, I chew Pur gum. It is certified diabetic friendly, dairy free, no GMOs, gluten free, nut free, vegan. And tastes great. The pomegranate is the best flavor, but it doesn’t last long at all. For great taste, and long lasting flavor I’d go with the peppermint.

    • Krystal says:

      reply above was for this comment, not for the licorice. People who made this website it should be made more clear i think.

    • Carol says:

      I have seen modified food starch from corn. The only way to be sure is to call the company. I wish these companies would learn that there are about 10% of the population that is gluten free to some extent so they would start putting meaningful labels on their products.

    • Linda B says:

      “Modified Food Starch” is not always made with wheat. When it is made with corn starch it is safe for most GF people.

  17. Melanie says:

    Chewing gum!

  18. Kate Dizzine says:

    From what I’ve seen and researched, Worchershire Sauce is gluten free … from website: Lea & Perrins® Worcestershire Sauce is cholesterol free, fat free, preservative free, gluten free and has 80% less sodium than soy sauce.

    • Krystal says:

      Well omissions beer on their packaging says GF, and on their website says they have their own standards for GF, not the USDA’s. Worcestershire gets me sick…. and maybe your body is ok with it, but it definitely has gluten in it….

    • Carol says:

      If you call the company, you will get an answer like Helena posted. “Lea and Perrins Worchestire sauce is only gluten free if it is made in the US, the Canadian brand contains wheat”

  19. Krysta Abbott says:

    Be careful when eating things that have been seasoned! Seasonings and spices are surprisingly not always filled with just salt and herbs. Ground black pepper was a big surprise to me! I figured pepper was just pepper but I’ve found many kinds with wheat flakes added to it as well! I always order my meats without seasonings when dining in a restaurant unless I can read the label.

    • Carol says:

      Was the the spice plain black pepper or was it a seasoning mix? McCormick claims their spices are gluten free, but some of their seasoning mixes may not be.

  20. Lindsey Squire says:

    Lea and Perrins Worchestire sauce is actually gluten free. It’s labeled as so on the bottled and I am incredibly sensitive and never had a problem while using it.

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