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. Necia says:

    Because I have been an avid label reader for close to 15 years, I stand by my own motto: “If you are not absolutely 100% positive it’s gluten free, don’t eat it.” Eating out can be a task, but most places will prepare your food the way you must have it prepared.

  2. John says:

    I Switched to Costco (Kirkland) Organic Chicken Stock; no “issues” and it an improvement over my old chicken broth… but I do have a ton of extra boxes in the cupboard.

  3. Tracy Michon says:

    Please be aware of medicine also, pill often contain gluten as a filler, including some birth control pills.

  4. Lauren says:

    Dunkin Donuts coffees all have a flavor enhancer that contains Gluten. Even their plain coffee. Their bags that you can brew at home seem to be free of it. I learned this from experience and confirmed it from a long time manager of a Dunkin Donuts.

  5. Deana says:

    I’m sad, I love peanuts and every time I flip over the bag to read the ingredients I see wheat. Why

  6. Lucy says:

    Also “Chicken Broth” sometimes it’s thickened with wheat, sometimes it’s not, but if it’s a sub-ingredient in something bigger and just listed as “chicken broth” on hte ingredients list, you have no way of knowing if it’s gluten free or not.

    Unfortunately, I figured that out from experience. You don’t have to!

  7. Donna Marie says:

    Look out for gluten in make-up products. I was reading the Avon book and a lipstick said it was fortified with wheat protein … Check everything!

  8. Kristen says:

    I’ve found gluten in many non-food items. Shea butter contains gluten, and so do a lot of shampoo/conditioners. So if you’re fully allergic to it, then you need to watch out what you put on your skin as well as in your body. I’m pretty weary of gummy candies and some gelatinous foods as well. Some of the vegan-friendly varieties contain gluten as an alternative to gelatin.

  9. Deneen Bowen says:

    Some sour creams use “modified food starch” as a filler. I continue to be so sad about the gluten content of licorice and some gummy bears!

  10. Laura says:

    I didn’t know that “fake crab” which is often found in California rolls (sushi) has wheat as a filler in it. I didn’t know this for years and used to eat them, The fish is called pollack, you will also find it in stick form (looks like crab) in the grocery stores, avoid it.

  11. pam says:

    I found out, the hard way, that those little candies that are a caramel circle around a white center – yeah – first ingredient is Wheat –

  12. jasmine says:

    I’m wondering why Worcestershire sauce is on here.
    The ingredients are anchovies, brine, tamarinds, molasses, garlic vinegar, chilies, cloves, shallots, and sugar.
    Where is the gluten?

    • Marissa says:

      I’m not sure where you got that information from, as Hebrew National Hot Dogs have even gone the extra mile to have “Gluten Free” written on the packaging and have been gluten free for years.

  13. Virginia says:

    Hebrew National Beef Hot Dogs have gluten.

    • Marissa says:

      I’m not sure where you got that information from, as Hebrew National Hot Dogs have even gone the extra mile to have “Gluten Free” written on the packaging and have been gluten free for years.

  14. Sheila says:

    Starbucks creme brule drink at Christmas. Didn’t even think about the caramel in it as it’s always been a yearly tradition for me and I had been diagnosed mid-year. Thought I was going to die on the forty minute drive home. 🙁

  15. Johanna Aubuchon says:

    Redvines licorice has wheat in it, much to my dismay. That one took me by surprise a little.

  16. Sarah McKinney says:

    The jar of Nestea Instant tea says it may contain wheat. Lipton instant tea has maltodextrin.Did not wxpect it in instant tea.

  17. Sara says:

    Worcestershire sauce: the Canadian and British versions are made with malt vinegar so contain gluten. The American version is made with white vinegar so is ok.

    Always read labels if you are visiting different countries too – Dairy Milk chocolate in UK, the label says it contains wheat, but in Canada, it does not.

  18. Marilyn says:

    I have found it in cottage cheese and sour cream.

  19. Kikkoman also makes a gluten free soy sauce. I got it at my local Fry’s/Kroger Grocery store. You can look it up on

  20. Linda B says:

    Caramel: sometimes it’s made with barley sugar and sometimes with cane sugar. I found out the hard way that Dunkin Donuts caramel swirl must be made with barley.

    • Les says:

      When I first realized that gluten was a problem for me, I was told by someone with celiac to always steer clear of caramel. I’ve seen things with caramel where the ingredients didn’t list wheat or gluten, but my daughter is the one who looks at me and says, “Don’t do it!”

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