Navigating Hydrolyzed and Fermented Products in the Gluten-Free World

The gluten-free market has exploded with innovative products, often labeled with terms like hydrolyzed and fermented. These products can be a source of confusion—especially for people with celiac disease or gluten intolerance. Let’s break down what these terms mean, the science behind them, and which foods are truly safe.

What Are Hydrolyzed and Fermented Products?

Hydrolyzed: Proteins—including gluten—are broken down into smaller pieces (peptides or amino acids) by enzymes or acids. These fragments may or may not trigger immune responses in people with celiac disease.
Fermented: Microorganisms (like yeast or bacteria) break down food components during processing—such as in beer, soy sauce, or sauerkraut. If gluten grains are used, fragments can remain even after fermentation.

Why This Matters for Celiacs and Gluten-Intolerant Individuals

Standard gluten detection tests may not reliably identify gluten fragments found in hydrolyzed or fermented foods. Because of this:

The US FDA only allows foods with hydrolyzed or fermented ingredients to be labeled “gluten free” if the original ingredients were gluten-free before processing, not because the processing made them safe.
For products like certain beers or soy sauces, “gluten-reduced” does not mean safe for celiacs—there could still be harmful fragments present.

What Is Gluten-Reduced Beer?

Gluten-Free Beer: Brewed from non-gluten grains (sorghum, rice, corn). Safe for celiacs.
Gluten-Reduced Beer: Brewed from wheat/barley, then treated to break down gluten. While this lowers detectable gluten, it does not guarantee safety for those with celiac disease.

“There is currently no scientifically validated method to quantify the gluten content in fermented foods, including beer, so the FDA prohibits beers made from gluten-containing grains from being labeled as ‘gluten-free’.”

Common Hydrolyzed and Fermented Ingredients That Contain Gluten

Hydrolyzed Products That Contain Gluten:

Hydrolyzed Wheat Protein: Used in soups, sauces, processed meats, snack foods, seasonings, baked goods, and some cosmetics—if not specified as gluten-free, assume it contains gluten.
Hydrolyzed Wheat Gluten: Found in some protein supplements, food texturizers, animal feeds, and bakery products—contains gluten.
Hydrolyzed Vegetable Protein (HVP): Often made from wheat unless labeled gluten-free.

Fermented Products That Contain Gluten:

Traditional Soy Sauce & Teriyaki Sauce: Most are brewed with wheat—unless labeled gluten-free, they contain gluten.
Malt Vinegar: Made from barley malt, contains gluten fragments and is not safe for celiacs.
Beer (regular and gluten-reduced): Brewed from barley or wheat. Even “gluten-reduced” is not considered safe.
Sourdough Bread (from wheat or rye flour): Fermentation doesn’t remove gluten, so these are not safe.
Miso (made with barley or wheat koji): Will contain gluten unless specifically gluten-free.

Other Processed Foods and Seasonings:

Packaged broths, powdered stocks, salad dressings, marinades, barbecue sauces, and certain lunch meats may use hydrolyzed wheat protein or malt vinegar. Always check labels.

Gluten-Free Hydrolyzed Vegetable Proteins

Hydrolyzed soy protein
Hydrolyzed pea protein
Hydrolyzed plant protein (from non-gluten sources)

These proteins are safe for celiacs if from non-gluten sources and labeled gluten-free.

Safe, Fermented Gluten-Free Foods

If the original ingredients are gluten-free and labeled as such, these are safe:

Yogurt, kefir, cheese, pickles, olives, sauerkraut, kimchi, gluten-free labeled beers and wines (brewed from gluten-free grains)

Bottom Line: Stay Safe, Stay Informed:

Avoid hydrolyzed/fermented products from gluten grains unless they’re specifically labeled gluten-free (meaning the ingredients were gluten-free before processing).
Gluten-reduced beers and processed foods are not safe for celiac disease—choose only products brewed or made entirely from non-gluten ingredients and labeled gluten-free.
Always look for transparent sourcing, certifications, and consult a healthcare professional when in doubt.

Awareness and label reading are your best tools in staying healthy and informed in the gluten-free world!