Cross-Contamination 4 min read

Invisible Gluten: Hidden Sources You're Missing

The surprising places gluten hides, beyond the obvious bread and pasta.

By Taylor Clark |

You’ve cut out bread, pasta, and obvious wheat products. You’re reading labels. You’re asking at restaurants. But you’re still getting glutened.

Where is it coming from?

Here are the hidden sources many celiacs miss.

Food Sources

Soy Sauce

The big one. Traditional soy sauce is made with wheat. It’s in:

  • Asian dishes (obviously)
  • Marinades and sauces
  • Salad dressings
  • Anything “teriyaki”
  • Fried rice seasonings

Solution: Use tamari or coconut aminos. Ask at restaurants: “Does this contain soy sauce?”

Malt

Malted barley is in more than you’d expect:

  • Malt vinegar (fish and chips, some dressings)
  • Malted milkshakes
  • Some cereals
  • Beer (obviously)
  • Malt flavoring in candy

On labels: “Malt extract,” “malt flavoring,” “malt syrup”

Oats (Uncertified)

Oats don’t naturally contain gluten, but they’re almost always cross-contaminated from growing and processing.

Only safe oats: Certified gluten-free oats

Breading and Battering

Anything fried that isn’t explicitly GF:

  • Fried chicken
  • Onion rings
  • Calamari
  • Tempura
  • Some french fries (coated)

Processed Meats

Some contain fillers:

  • Sausages
  • Hot dogs
  • Deli meat
  • Meatballs
  • Meat patties

Check labels or ask: Many are fine, but some aren’t.

Soup and Broth

Flour is a common thickener:

  • Cream soups
  • Gravy
  • Stock cubes (some)
  • Restaurant soups

Salad Dressings

Hidden wheat in:

  • Some vinaigrettes
  • Creamy dressings
  • Marinades used as dressings

Sauces and Gravies

Flour-thickened:

  • Gravy
  • White sauce
  • Some tomato sauces
  • Chinese sauces
  • BBQ sauce (check ingredients)

Communion Wafers

Obviously. But worth mentioning, standard hosts are wheat.

Solution: Low-gluten hosts or chalice only.

Non-Food Sources

Medications and Supplements

Gluten is used as a binder in some pills:

  • Prescription medications
  • Over-the-counter drugs
  • Vitamins and supplements

How to check: Ask your pharmacist, or look up the inactive ingredients. Many manufacturers now specify GF.

Lip Products

You swallow what’s on your lips:

  • Lipstick
  • Lip balm
  • Lip gloss

Solution: Check ingredients or use explicitly GF products.

Toothpaste and Mouthwash

Some contain gluten-derived ingredients:

  • Most major brands are fine
  • Check specialty/natural brands

Play-Doh

If you have kids (or teach):

  • Play-Doh is wheat-based
  • Kids put it in their mouths
  • You touch it, then eat

Solution: GF play dough exists. Or just be careful about handwashing.

Envelopes and Stamps

Old-style lick-and-stick:

  • Some use wheat-based glue
  • Most modern products are synthetic

Solution: Use self-adhesive or wet with a sponge.

Communion

We’ve covered it, but: standard hosts contain wheat. Low-gluten hosts or wine-only are safe options.

Restaurant Traps

Shared Fryers

Even if your food is GF, if it’s fried in oil that also fries breaded items:

  • Fries fried with chicken nuggets
  • GF fish fried with regular fish
  • “GF” items in shared oil

Pasta Water

Cooking GF pasta in water that cooked regular pasta.

Shared Grills

Bread toasted on the grill, then your meat cooked there.

”We’ll Just Remove It”

  • Croutons picked off salad
  • Bun removed from burger
  • Bread pulled out of a sandwich

Cross-contact has already happened.

Seasoning Blends

House seasonings may contain wheat. Ask.

”Modified” Dishes

When you ask for modifications, there’s more room for error:

  • Sauces on the side that still dripped
  • Items that “usually come with” something that touched yours

Sneaky Ingredient Names

On labels, gluten hides as:

  • Wheat (obvious)
  • Barley
  • Rye
  • Malt (barley)
  • Brewer’s yeast
  • Hydrolyzed wheat protein
  • Seitan
  • Kamut
  • Spelt
  • Triticale
  • Farina
  • Semolina
  • Durum

Less obvious (usually safe but check):

  • Modified food starch (usually corn, if wheat, must be labeled in US)
  • Maltodextrin (usually corn-derived in US)
  • Dextrin (check source)
  • Natural flavors (rarely contain gluten but possible)

The Detective Process

When you’re still getting sick despite being “careful”:

  1. Food journal: Write everything you eat for 2 weeks. Note symptoms.

  2. Pattern recognition: What were you eating when you got sick?

  3. Label audit: Re-read labels on things you assumed were safe.

  4. Medication check: List all pills and verify they’re GF.

  5. Kitchen audit: With a dietitian if possible.

  6. Lifestyle check: Lip products, toothpaste, etc.

  7. Restaurant audit: Are you eating out more than you realized? Which places?

Often the source is something you’ve been eating regularly without suspecting it.

The Upside

Once you identify hidden sources, you eliminate them. The detective work is temporary. The knowledge is permanent.

And once you’ve found the culprit, the symptoms stop.

Keep investigating. The source is findable.

hidden gluten labels awareness