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. Dev says:

    PRESCRIPTIONS, otc drugs and vitamins. Toothpaste and mouthwash. Makeup, lotion, shampoo conditioner and hair product. My neices glue, playdough, stickers (esp mailer adhesive). Dish detergent, and laundry detergent.

  2. Heather says:

    I had no idea that some brands of bouillon cubes had wheat in them. It didn’t even dawn on me till I got them home and happened to glace at the label. Also some taco seasonings. I get mine at Penzey’s Spices now. It’s GF and super yummy.

  3. Bill Donnelly says:

    Lindsey: if your grocery store carries Sweet Baby Ray’s BBQ sauce, it is labeled GF and my Celiac wife (very sensitive) loves it. Here (central NJ) it is available in most every grocery store, with several varieties (not sure all are GF), and not super expensive.

  4. Bill Donnelly says:

    My wife is very sensitive, and she has no problem at all with the Progresso soups with modified food starch. (Finding them on sale is a whole different question!)

    My stealth gluten source is Red #5 food coloring. My wife has had reactions to this even in minuscule amounts. It shows up in things like store-brand NyQuil (the real stuff from Vicks is safe) or maraschino cherries, and no we’re wary of anything that’s unnaturally red.

  5. Susan Ashton says:

    Dry mustard – they use it as an anti-clumping agent!!

  6. Susie says:

    I had a really bad allergic reaction (wheezing and numb lips) to some frozen ravioli I bought. I don’t remember the brand, but it claimed to be gluten-free. I read the package and the only sign something might be wrong was it said “We take great care to separate our ingredients in a facility that also makes products containing wheat.” Yep. Should have left it there, but I thought sure…they’re separating them. All is good.

    Oh…and sometimes hamburgers in restaurants come from a box and often those boxed burgers have wheat filler in them. You really won’t know that unless you ask to read the label. I always assumed a burger would naturally be wheat free.

  7. Dee says:

    Not all Worcestshire sauce is GF. Lea and Perrins is, but some others aren’t. Many cocktail drink mixes (like Bloody Mary mixes) will use unsafe Worcestshire sauce. Never order one from a bar without first checking that the mix they use is okay. I found this out the hard way from drinking Zing Zang mixer.;)

  8. Kim Rylee says:

    Immitation crab meat and pre packaged chicken, tuna, and seafood salads all have wheat in them.

  9. Cyndi Ivy says:

    The only times I have been surprises are the times I have gotten ill from a “gluten free” menu selection. Unfortunately, those items have taught me to ask first and trust later. A lot of restaurants offer “gluten free” and have an open air kitchen in which they are not able to protect plates. Even if your food is gluten free, there may be trace amounts from flour and other things in the air at those places. I actually got sick from a garden salad due to this.

  10. Carol says:

    Many stores are unclear about the gluten free concept. They label their shelves gluten free and stock them with organic items that are not gluten free.

  11. Barb says:

    Lea and Perrins contains high fructose corn syrup. That is as bad as gluten!

  12. Diane Gibson says:

    Sweet Baby Ray’s barbecue sauce is gluten free and very good too!

  13. Mike says:

    Will this new labeling criteria really help if they are allowing *some* gluten to be labeled as GF?

  14. Cathy says:

    Cracker Jack’D (the new spicy Cracker Jacks) all have wheat in them.

  15. Mary says:

    It is my understanding that if wheat is contained in a product, it must say so on the label. Therefore, if a product contains “modified food starch”, and the label does not say “wheat”, the modified food starch is NOT FROM WHEAT. This is a common misinterpretation and comes from the days before it was a requirement to disclose wheat as an ingredient.

  16. Ron Goossen says:

    Make sure you check out french fries. Many fast food chains have put flour on their fries.

  17. Mary says:

    Sweet Baby Ray’s is gluten free!

  18. nancy says:

    Godiva chocolate has gluten !

  19. Leisa PS says:

    EPICURE spices and products are gluten-free (and state this in their catalogues). I highly recommend their Balsamic Viniagrette spices: I toss diced potatoes with a little olive or canola oil and sprinkle them with this before baking, use it in soups, stews and stir fries, sauté onions, zucchini, garlic and mushrooms with it, sprinkle it on meat such as chicken breasts, roasts and pork chops, and, of course, combine it with balsamic vinegar and oil to make it into an exceptional salad dressing! (I don’t sell the stuff, but I certainly do order lots of it!)

  20. Matt says:

    I have read and heard something about modified food starch and corn starch in the US. According to what I’ve been told and read, companies have to specify if that modified corn or food starch has wheat in it. You can usually see allergen information as well below the ingredient list. So if someone used wheat in their modified starch it would say Contains: Wheat below the ingredients. I have noticed that most western family brand items do not have gluten, by the way. I have some of their worchestire sauce at home. Also Stubbs BBQ sauce is a great brand that is gluten free and not terribly expensive and found in most grocery stores.

Leave a Reply

Your email address will not be published.

Time limit is exhausted. Please reload the CAPTCHA.