Hidden Gluten in Packaged Foods: What I Wish I'd Known Sooner

When my daughters were diagnosed with celiac disease, I thought going gluten free was straightforward. I replaced everything obvious: flour, pancakes, cereal, granola, waffles, bagels, bread, crackers, tortillas, pasta, cookies, cake, muffins, breadcrumbs. All swapped for gluten free versions. Done, right?

Not quite.

A few months in, I noticed a pattern: random stomach aches I couldn't explain. So I started keeping a food journal- every meal, every ingredient. After a few weeks, the culprits emerged: a grilled steak marinated in homemade sauce. A fresh salad with store-bought dressing. A bowl of Rice Krispies for breakfast.

I had no idea I was still making them sick.

Gluten Hides in Plain Sight

Here's what I discovered the hard way:

What surprised me most was my own assumption: if the ingredient list didn't say "wheat," I thought we were safe. We weren't.

Why Labels Don't Always Help

The FDA does have a standard for "gluten free" labeling; products must contain fewer than 20 parts per million of gluten. But not all manufacturers choose to use that label, and there's no required placement on the package and no FDA-approved certification body in the U.S. to verify it. That inconsistency makes it genuinely hard to shop with confidence.

If you are curious you can read more on FDA labeling guidelines can be found on the government's Food Safety website.

How to Read a Label Like a Pro

The first thing is to obviously look for a “certified gluten free” label or the text “gluten free” on the front of the food packaging. However, as this isn’t required in the US, you won’t always have this easy shorthand, so here are a few shortcuts that have become second nature for me:

  • Check the allergen statement first. Look for "Contains: Wheat" at the bottom of the ingredient list. This is required disclosures in the U.S. and is the fastest check.
  • "Malt" is a red flag. Malt and malt flavoring are almost always derived from barley.
  • Watch for vague terms. "Natural flavors," "dextrin," and "stabilizers" can all be sources of hidden gluten.
  • Look for certified gluten free logos when available as they indicate third-party testing, not just a manufacturer's claim. Beyond Celiac has great visuals of what these labels look like.

🛒 Ingredients to Watch Out For

Even tiny amounts of gluten can trigger symptoms in people with celiac disease or gluten sensitivity which is what makes hidden sources so frustrating. The checklist below covers the ingredients most likely to catch you off guard: things that aren't obviously wheat-based but can absolutely derail a gluten free diet.

1. Grain-derived ingredients

(Not always labeled clearly)

  • Malt / Malt extract / Malt syrup / Malt flavoring → almost always from barley
  • Barley enzymes / Barley malt vinegar
  • Brewer’s yeast (can be a byproduct of beer brewing)
  • Wheat starch (sometimes processed to remove gluten, but not always safe unless labeled GF)
  • Hydrolyzed wheat protein
Example: Rice Krispies cereal seems like it is gluten free as it is made with rice, but it contains a malt flavoring that coats the cereal that contains gluten.
2. Ambiguous additives & flavorings

These can be gluten-free—but sometimes aren’t depending on the source:

  • Natural flavors / Artificial flavors
  • Smoke flavoring
  • Caramel color (usually safe in the U.S., but varies globally)
  • Seasoning blends / spice mixes
  • Modified food starch (in the U.S. typically corn, but check if outside U.S.)
  • Hydrolyzed vegetable protein (HVP)
  • Textured vegetable protein (TVP) (may include wheat)
Example: Doritos Nacho Cheese Flavored Tortilla Chips – Ingredients like “natural flavors” and seasoning blends can include hidden gluten sources, depending on formulation and region. But more importantly Doritos are made in facilities that share production lines with products that contain gluten so have higher cross contamination possibilities.
3. Sauces, condiments & flavor bases

Very common gluten traps. Look specifically for wheat-containing thickeners or soy sauce bases as these indicate a sauce/condiment that is not gluten free.

  • Soy sauce (traditionally brewed with wheat)
  • Teriyaki sauce
  • Gravy mixes / bouillon cubes
  • Salad dressings
  • Marinades
  • Barbecue sauce
Example: Wish-Bone Creamy Caesar dressing contains soy sauce which has wheat in it so this salad dressing is not gluten free.
4. Processed & packaged foods

These categories often contain hidden gluten even if they don’t seem like “bread products”:

  • Deli meats / processed meats (fillers, binders)
  • Plant-based meats (often use wheat gluten / seitan)
  • Soups (especially creamy or thickened)
  • Snack foods (chips, crackers, flavored nuts)
  • Candy (especially licorice, malted products, crispy inclusions)
  • Ice cream (cookie pieces, brownie bits, thickeners)
  • Pre-seasoned rice or grain mixes
Example: Campbell's New England Clam Chowder contains wheat flour as a thickener, even though it doesn’t seem like a “gluten food.”
5. Thickeners & stabilizers
  • Roux (flour-based thickener)
  • Wheat flour (obviously, but sometimes buried in blends)
  • Farina / semolina / durum (forms of wheat not always recognized)
  • Einkorn, spelt, kamut (ancient wheat varieties)
Example: Knorr Chicken Flavor Bouillon Cubes contain autolyzed yeast extract (barley) thickeners to enhance texture.
6. Alcohol & fermented products
  • Beer / ale / lager (barley-based unless labeled gluten-free)
  • Malt beverages
  • Some flavored alcoholic drinks
Example: Guiness Beer is made with barley, which contains gluten, even though it’s not always top-of-mind as a “wheat product.” This is important to keep in mind as you cook when some recipes such as chili call for beer in the cooking process!
"Looks safe but check anyway"

These are often gluten-free, but worth verifying:

  • Oats (can be cross-contaminated unless labeled GF)
  • Corn products (possible cross-contact)
  • Chocolate (shared facilities)
  • French fries (cross-contact in fryers or coatings)