Hidden Sources of Gluten: What Every Gluten-Free Eater Needs to Know

Common condiments and treats can undermine strict diets before you even notice.

By Medha deb

Created on Sep 24, 2025

Common condiments and treats can undermine strict diets before you even notice.

Adopting a gluten-free diet is a necessity for individuals with celiac disease, gluten intolerance, or those choosing to avoid gluten. While common culprits like bread and pasta are obvious sources, gluten can hide in far less expected places. Knowing these hidden sources of gluten is crucial for anyone needing to maintain a truly gluten-free life.

What is Gluten?

Gluten is a protein found primarily in wheat, barley, rye, and their derivatives. It provides elasticity to dough and helps baked goods hold their shape. However, for some individuals, even tiny amounts of gluten can trigger serious health issues. That’s why recognizing unexpected sources matters just as much as avoiding the main offenders.

Common Grains and Ingredients That Contain Gluten

Wheat (including varieties like durum, spelt, emmer, farro, kamut, and einkorn)
Barley
Rye
Triticale (a wheat-rye hybrid)
Malt and malt derivatives (from barley)
Wheat starch (unless processed to remove gluten)

Additionally, several wheat-based flours and products are not gluten-free:

Enriched wheat flour
Self-rising flour
Graham flour
Semolina
Farina

Obvious Food Sources of Gluten

Most people on a gluten-free diet already know to avoid foods made directly from wheat, barley, or rye. These include:

Bread and baked goods: breads, bagels, muffins, doughnuts, croissants, cakes, and cookies
Pasta and noodles: spaghetti, macaroni, lasagna, ravioli, dumplings, egg noodles, couscous
Cereal and granola: many breakfast cereals, granola bars
Crackers and pretzels: crackers, pretzels, pita chips, croutons
Beer and malt beverages

Hidden Gluten: Where It Lurks Unexpectedly

“Gluten isn’t really hiding, but you have to check ingredients carefully,” emphasizes experts. Many items that appear gluten-free at first glance might have gluten-containing additives, thickeners, or flavorings. Here are some of the most common—but less obvious—places where gluten can sneak into your diet:

Sauces & Condiments

Soy sauce and Teriyaki sauce: Typically brewed with wheat, unless labeled gluten-free.
Salad dressings: May contain malt vinegar, flour, or soy sauce.
Marinades & Barbecue sauces: Sometimes thickened with wheat flour or include malt vinegar.
Gravies and creamy sauces: Often thickened with a “roux” (mixture of wheat flour and fat).
Malt vinegar: Made from barley malt and not gluten-free.
Soup bases and bouillon cubes: Sometimes include wheat-based thickeners.

Processed Foods and Snack Items

Corn flakes & crisp rice cereal: Some brands use malt flavoring from barley.
Flavored chips and snack mixes: May contain wheat-based flavorings or batter.
Granola and energy bars: Unless certified gluten-free, may use regular oats or wheat-based sweeteners.
Licorice and malted milk balls: Contain wheat flour or barley malt.
Ice cream: Some flavors add cookie dough, brownies, or malt flavoring.
Trail or snack mixes: May include pretzels or wheat-based seasonings.

Seasonings & Mixes

Taco seasoning: Some varieties include wheat flour as a filler or thickener.
Breading and coating mixes: panko, seasoned flour mixes.
Pancake and waffle mixes: Unless gluten-free, these are based on wheat flour.
Stuffing/dressing mix and croutons: Most use wheat bread as the base.

Beverages & Alcohol

Beer, ale, lager, and stout: Made from barley and not gluten-free unless specified.
Malt beverages or flavored alcoholic drinks: Often contain barley malt.
Wine coolers: Sometimes made with malt.
Malted milkshakes: Contain malt powder from barley.

While most distilled spirits are considered gluten-free due to the distillation process, always double-check for potential additives.

Nonfood Sources of Hidden Gluten

Because gluten acts as a binding or thickening agent, it is used in several surprising places outside of food. Always check labels or consult manufacturers for the following products:

Medications and supplements: Some chewable tablets and capsules use wheat-based fillers or binders.
Vitamins and nutritional supplements: May contain wheat starch or maltodextrin.
Cosmetics: Lipstick, lip gloss, or lotion can sometimes contain gluten-derived ingredients.
Dental products: Certain mouthwashes and toothpastes.
Children’s modeling clay and craft supplies: Some contain wheat flour as a binder.
Communion wafers: Traditionally made with wheat. Gluten-free versions are available.

Unexpected Foods That Often Contain Gluten

Food/Product	Reason Gluten May Be Present
Soy Sauce	Often brewed with wheat; opt for tamari or labeled gluten-free.
Salad Dressing	Malt vinegar, soy sauce, or flour added.
Soup and Gravy	Thickened with wheat flour (roux).
Flavored Chips/Snacks	Seasonings or coatings with wheat flour.
Beer/Malt Beverages	Brewed from barley. Choose gluten-free beer brands.
Processed Meat/Imitation Seafood	Fillers or coatings with wheat.
Breakfast Meats (sausages, scrapple)	May contain wheat-based fillers.
Ice Cream (Certain Flavors)	Added cookie dough, malt, or brownies.
Baking Powder	Some brands use wheat starch as a filler.
Imitation Crab/Surimi	Typically contains wheat-based binder.
Bouillon Cubes/Soup Base	Sometimes thickened with wheat flour.

How to Avoid Hidden Gluten

Vigilance is your best defense against accidental gluten exposure. Here’s how to stay safe:

Read every label, every time: Ingredients change often! Look for wheat, barley, rye, malt, and their derivatives.
Watch for “modified food starch”: In the U.S., this is usually corn, but if it’s wheat it will be labeled as such.
Check for cross-contamination: Especially with bulk bin items, shared kitchen appliances, or restaurant-prepared foods.
Contact manufacturers or restaurants: When in doubt about a product’s gluten content.
Choose certified gluten-free products: For peace of mind, look for trusted certification logos.

Frequently Asked Questions (FAQs)

Q: What are the most surprising foods that contain gluten?

A: Many salad dressings, soy sauce, flavored chips, processed meats, and even some ice creams contain gluten. Always check the labels, as these foods don’t always make it obvious.

Q: Can gluten be present in medications or supplements?

A: Yes, gluten-derived fillers may be used in some medications and supplements. Always check with your pharmacist and ask manufacturers if a product is safe for a gluten-free diet.

Q: Are oats gluten-free?

A: Pure oats are naturally gluten-free but are often contaminated during processing. Choose oats specifically labeled gluten-free.

Q: What should I do if an ingredient label isn’t clear?

A: If the source of an ingredient like “modified food starch” or “dextrin” isn’t identified as gluten-free, contact the manufacturer directly or choose an alternative with clear gluten-free labeling.

Q: Are alcoholic beverages gluten-free?

A: Most distilled liquors are gluten-free, but beer, ales, and malt beverages are not. Look for specifically labeled gluten-free versions if you must avoid gluten due to medical reasons.

Label-Reading Tips for Gluten-Free Living

Wheat-free does not mean gluten-free: Gluten can be in many grains besides wheat.
Look for gluten-free certification: Certification offers additional safety assurance.
Caution with imported products: Labeling requirements vary by country.
Understand alternative names: Watch for ingredients like “seitan” (pure wheat gluten), “maltodextrin” (from wheat in some countries), “hydrolyzed wheat protein,” and “textured vegetable protein” if not specifically listed as gluten-free.

Final Thoughts: Staying Ahead of Hidden Gluten

While eliminating obvious sources is a good start, knowledge of hidden gluten is essential for anyone with celiac disease or non-celiac gluten sensitivity. Stay informed, vigilant, and proactive when it comes to reading labels and asking questions. The more you know about where gluten can hide, the safer and healthier your gluten-free lifestyle will be.

References

Author

medha deb

Medha Deb is an editor with a master's degree in Applied Linguistics from the University of Hyderabad. She believes that her qualification has helped her develop a deep understanding of language and its application in various contexts.

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