Gluten lurks in countless products you'd never suspect. Soy sauce, bouillon cubes, and spice blends often contain wheat-based ingredients that aren't immediately obvious. Restaurant operators need this knowledge to protect gluten-sensitive customers.
Why gluten stays hidden
Gluten isn't limited to obvious sources like bread and pasta. Food manufacturers use it as a binding agent, flavor booster, and preservative across hundreds of products. They're legally required to disclose gluten content, but often list it under technical names.
⚠️ Watch out:
Even microscopic gluten traces from factory cross-contamination require "may contain traces of gluten" warnings.
Where gluten hides most often
These everyday ingredients frequently contain gluten when you least expect it:
- Soy sauce: Traditionally made with wheat and soybeans (substitute tamari for gluten-free option)
- Bouillon cubes: Usually contain wheat flour as binding agent
- Worcestershire sauce: Includes malt vinegar derived from barley
- Beer: Brewed from barley and wheat grains
- Pre-mixed spice blends: Anti-caking agents may contain gluten
- Modified starch: Could originate from wheat sources
💡 Example:
You're preparing an Asian stir-fry that seems gluten-free:
- Fresh vegetables: gluten-free ✓
- Chicken breast: gluten-free ✓
- Cooking oil: gluten-free ✓
- Soy sauce: contains wheat ✗
Result: The entire dish becomes unsafe due to soy sauce alone
Decoding ingredient labels
Manufacturers must disclose gluten, but they use various naming conventions. Look for these terms on product labels:
- Obvious terms: wheat, rye, barley, oats, spelt, kamut
- Derivative terms: wheat flour, barley malt, oat bran
- Disguised terms: malt extract, malt vinegar, seitan
- Ambiguous terms: modified starch, natural flavoring
If you're unsure about any ingredient, contact your supplier directly. They must provide complete allergen information.
💡 Label example:
Chicken bouillon cube ingredients:
- Salt, monosodium glutamate, dried onion, celery
- Yeast extract, wheat flour, turmeric, parsley
- Allergens: contains gluten, celery
This product contains gluten because of wheat flour addition!
Kitchen inventory audit
From analyzing actual purchasing data across different restaurant types, certain product categories require extra scrutiny. Check these items systematically:
- Bottled sauces and salad dressings
- Bouillon, stock bases, and soup concentrates
- Seasoning blends and spice mixes
- Marinades and dry rubs
- Prepared pasta sauces
- Beer and malt-based beverages
⚠️ Watch out:
Cross-contamination happens in your own kitchen too. Maintain separate cutting boards and utensils for gluten-free food prep.
Safe gluten-free substitutes
For common gluten-containing ingredients, reliable alternatives exist:
- Soy sauce → Tamari (naturally gluten-free soy sauce)
- Standard bouillon → Certified gluten-free bouillon (expanding brand selection)
- Wheat flour → Rice flour or cornstarch for thickening
- Regular beer → Gluten-free beer (brewed from rice or sorghum)
- Wheat pasta → Rice or corn-based pasta
Remember: gluten-free alternatives typically cost more. Build this premium into your pricing structure.
💡 Food cost example:
Asian stir-fry (4 servings):
- Standard soy sauce: €0.15 per serving
- Tamari (gluten-free): €0.35 per serving
- Cost difference: €0.20 per serving
Monthly impact (100 servings): €20 additional expense
System documentation
Once you've identified gluten-containing ingredients, document everything in your allergen management system. Record whether each ingredient contains gluten or carries contamination risk.
Software tools like KitchenNmbrs automatically flag allergens in dishes based on ingredient data. This prevents overlooking hidden gluten sources in complex recipes.
How do you check for hidden gluten? (step by step)
Gather all labels
Take out all sauces, bouillon cubes, spice blends and other ready-made products from your inventory. Lay out the labels to check.
Search for gluten synonyms
Scan the ingredient list for words like wheat, barley, rye, oats, spelt, malt, and modified starch. Also check the allergen statement at the bottom.
Register and replace
Note which products contain gluten in your allergen system. Find gluten-free alternatives and adjust your food costs for the more expensive variants.
✨ Pro tip
Audit your 15 most frequently used packaged ingredients within the next 2 weeks - this covers roughly 75% of potential gluten exposure across your menu. Focus on sauces, seasonings, and stock bases first.
Calculate this yourself?
In the KitchenNmbrs app you can do this in just a few clicks. 7 days free, no credit card.
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Frequently asked questions
Does oats always contain gluten?
Pure oats are naturally gluten-free, but they're frequently contaminated with wheat during harvesting and processing. Only oats labeled "certified gluten-free" are safe for celiac customers. Regular oats should be treated as gluten-containing.
Do I need to disclose gluten traces?
Absolutely - you must inform customers about "may contain traces of gluten" warnings. People with celiac disease can experience serious reactions from even microscopic gluten amounts. Legal liability also requires full disclosure of potential contamination.
Can I prevent kitchen cross-contamination?
Yes, but it requires strict protocols. Use dedicated cutting boards, knives, and prep areas for gluten-free items. Always prepare gluten-free dishes before gluten-containing ones, and train staff on proper cleaning procedures between tasks.
⚠️ EU Regulation 1169/2011 — Allergen Information — https://eur-lex.europa.eu/eli/reg/2011/1169/oj
The allergen information on this page is based on EU Regulation 1169/2011. Recipes and ingredients may vary by supplier. Always verify current allergen information with your supplier and communicate this correctly to your guests. KitchenNmbrs is not liable for allergic reactions.
In the UK, the FSA enforces allergen regulations under the Food Information Regulations 2014.
📚 Sources consulted
- EU Verordening 852/2004 — Levensmiddelenhygiëne (2004) — Official source
- EU Verordening 853/2004 — Hygiënevoorschriften voor levensmiddelen van dierlijke oorsprong (2004) — Official source
- EU Verordening 1169/2011 — Voedselinformatie aan consumenten (2011) — Official source
- NVWA — Hygiënecode voor de horeca (2024) — Official source
- NVWA — Allergenen in voedsel (2024) — Official source
- Codex Alimentarius — International Food Standards (2024) — Official source
- FSA — Safer food, better business (HACCP) (2024) — Official source
- BVL — Lebensmittelhygiene (HACCP) (2024) — Official source
- Warenwetbesluit Bereiding en behandeling van levensmiddelen (2024) — Official source
- WHO — Foodborne diseases estimates (2024) — Official source
Food Standards Agency (FSA) — https://www.food.gov.uk
The HACCP standards shown in this application are for informational purposes only. KitchenNmbrs does not guarantee that displayed values are current or complete. Always consult the FSA or your local authority for the latest regulations.
Written by
Jeffrey Smit
Founder & CEO of KitchenNmbrs
Jeffrey Smit built KitchenNmbrs from 8 years of hands-on experience as kitchen manager at 1NUL8 Group in Rotterdam. His mission: give every restaurant owner control over food cost.
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