How to Figure Out What Has Gluten in It?

October 21, 2025 •

4 min read

According to the Celiac Disease Foundation, more than 3 million Americans have celiac disease, requiring them to avoid gluten entirely. Learning how to figure out what has gluten in it is a vital skill for managing a gluten-free lifestyle, and involves more than just avoiding bread and pasta.

Quick Summary

This guide provides a comprehensive approach to identifying gluten sources, from understanding common ingredients to navigating complex food labels and preventing cross-contamination in the kitchen.

Key Points

Know the Core Grains: Identify the main gluten-containing grains: wheat, barley, and rye, and their derivatives.
Master Label Reading: Look for 'certified gluten-free' labels and always read the full ingredient list for hidden sources and additives.
Beware of Hidden Gluten: Many processed foods, from sauces and seasonings to lunch meats and candy, contain unexpected gluten.
Prevent Cross-Contamination: Separate cooking surfaces, utensils, and condiments from gluten-containing foods, especially if you have celiac disease.
Trust Certifications: 'Certified gluten-free' labels provide greater assurance of low gluten levels and manufacturing safety than self-declared 'gluten-free' claims.
'Wheat-Free' ≠ 'Gluten-Free': Do not mistake a 'wheat-free' label for a 'gluten-free' one, as it can still contain other gluten grains like barley or rye.

Navigating a gluten-free diet can be challenging, but with the right knowledge and tools, it becomes a manageable part of everyday life. Identifying gluten requires vigilance, as it appears in many obvious foods as well as in surprising, hidden forms. The first step is to recognize the grains that naturally contain gluten: wheat, barley, and rye. However, the presence of gluten extends far beyond these simple grains.

Reading Food Labels for Obvious and Hidden Gluten

Reading a food label effectively is the most critical skill for anyone managing a gluten-free diet. The FDA defines a product as 'gluten-free' if it contains less than 20 parts per million (ppm) of gluten. In some countries, including the UK and EU, allergens like wheat must be emphasized in bold within the ingredients list. However, this is not a universal standard and doesn't cover barley and rye in all regions, requiring extra attention to detail.

Always Check for These Gluten-Containing Ingredients:

Wheat: Found in wheat flour, spelt, durum, semolina, kamut, farro, and more.
Barley: Look for barley flakes, flour, malt extract, malt syrup, and brewer's yeast.
Rye: Commonly found in rye flour, rye bread, and triticale.
Malt: A flavoring often derived from barley, found in cereals, candies, and malt vinegar.
Oats: While naturally gluten-free, oats are highly susceptible to cross-contamination during processing and must be labeled 'certified gluten-free' to be considered safe.

Watch Out for Hidden or Disguised Gluten

Many processed and packaged foods contain gluten in unexpected places. You need to look beyond the main ingredients for additives that can contain gluten.

Thickeners and Stabilizers: Modified food starch, dextrin, and hydrolyzed vegetable protein (HVP) can be derived from wheat.
Seasonings and Flavorings: Many pre-made seasoning blends, soy sauce, teriyaki sauce, and even some vinegars contain wheat or malt.
Meat Products: Processed lunch meats, hot dogs, and meat substitutes like veggie burgers often use gluten as a binder or filler. Self-basting poultry may also contain added gluten.
Condiments and Sauces: Besides soy sauce, many salad dressings, marinades, and gravies are thickened with wheat flour or contain malt vinegar.
Candy and Snacks: Flavored chips, snack bars, and certain candies can contain gluten in their coatings or binders.

Avoiding Cross-Contamination in the Kitchen

Even if you are vigilant about ingredients, gluten can accidentally transfer to gluten-free foods during preparation, a process known as cross-contamination. For individuals with celiac disease, even a tiny amount of gluten can be harmful.

How to Minimize Risk at Home

Dedicated Equipment: Use separate cutting boards, colanders, toasters, and utensils for gluten-free cooking. Porous materials like wood are especially risky.
Separate Condiments: Use separate jars of butter, jam, and spreads to prevent contamination from crumb-covered knives. Squeeze bottles for condiments are a safer shared option.
Storage Protocols: Store gluten-free foods on higher shelves than gluten-containing items to prevent spills from falling onto them. Use clearly labeled, airtight containers.
Cooking Surfaces: Thoroughly clean counters, pots, and pans with hot, soapy water before preparing gluten-free food. Consider using separate pots for cooking gluten-free pasta.
Frying Oil: Never fry gluten-free items in oil that has been used for breaded or battered foods, as gluten particles can remain in the oil.

Comparison Table: Common Ingredients and Gluten Status


Ingredient	Gluten Status	Notes
Wheat Flour	Contains Gluten	Used in breads, pastas, cakes, and as a thickener.
Rice Flour	Gluten-Free	Safe for baking and thickening, a common substitute.
Barley Malt	Contains Gluten	Found in beer, cereals, and some flavorings.
Tamari	Gluten-Free	A gluten-free alternative to traditional soy sauce, check label to be sure.
Malt Vinegar	Contains Gluten	Derived from barley, use distilled vinegar instead.
Distilled Vinegar	Gluten-Free	Gluten is removed during the distillation process.
Oats	Potential Contamination	Only safe if labeled 'certified gluten-free' due to cross-contact risks.
Quinoa	Gluten-Free	A healthy, naturally gluten-free grain.

The Role of Certification and Labels

While you should always read the ingredient list, a 'certified gluten-free' label offers an extra layer of assurance. Third-party organizations often verify that products meet a stricter standard (e.g., less than 10 ppm) and are produced in facilities with stringent cross-contamination controls. A 'wheat-free' label is not the same as 'gluten-free,' as a product can be wheat-free but still contain barley or rye.

Conclusion

Understanding how to figure out what has gluten in it is a process that begins with knowing the primary sources—wheat, barley, and rye—and extends to becoming a proficient label-reader. By checking for hidden ingredients, watching for certified labels, and practicing diligent cross-contamination prevention, you can confidently navigate your diet and protect your health. If you are ever in doubt about an ingredient or product, always err on the side of caution or contact the manufacturer directly for clarification. Knowledge and careful habits are your best defense against accidental gluten exposure, allowing you to live safely and healthily on a gluten-free diet.

Frequently Asked Questions

A 'wheat-free' product does not contain wheat but may still have other gluten-containing grains like barley or rye. 'Gluten-free' means the product contains no wheat, barley, rye, or their crossbred hybrids.

No, oats are naturally gluten-free but are often processed in facilities that also handle wheat, leading to cross-contamination. Only consume oats that are specifically labeled 'certified gluten-free' to ensure safety.

Hidden gluten can be found in a variety of foods, including soy sauce, many salad dressings, marinades, flavored chips, processed meats like hot dogs, some deli meats, and even certain candies.

To prevent cross-contamination, use separate cutting boards, toasters, and colanders for gluten-free foods. Store gluten-free items separately and above gluten-containing ones. Clean surfaces and utensils thoroughly with hot, soapy water.

No, malt vinegar is made from barley and contains gluten. It should be avoided on a gluten-free diet. Distilled vinegars are safe, as the distillation process removes gluten peptides.

A 'certified gluten-free' label indicates that a third-party organization has verified the product meets strict standards, often containing less than 10 ppm of gluten. This offers a higher level of assurance than an uncertified claim.

Not necessarily. Many brands offer certified gluten-free processed foods, such as bread, pasta, and snacks. You must read labels carefully and prioritize certified options to ensure safety.