Barley contains gluten, and enough of it to be off-limits for anyone with celiac disease or gluten sensitivity. Raw barley averages about 7.2 grams of gluten per 100 grams of grain, which is lower than most bread wheats but still well above the threshold that triggers an immune response. The FDA classifies barley as a gluten-containing grain alongside wheat and rye, and any food made with barley cannot carry a “gluten-free” label unless it has been processed to contain fewer than 20 parts per million of gluten.
How Barley Gluten Compares to Wheat
The gluten-forming protein in barley is called hordein, which plays the same role that gliadin and glutenin play in wheat. Hordein belongs to a family of storage proteins called prolamins, all rich in the amino acids proline and glutamine. These are the specific protein sequences that the immune system of someone with celiac disease reacts to. Wheat, rye, and barley all contain their own version of prolamins, which is why all three grains are grouped together as gluten sources.
At 7.2% gluten by weight, barley carries a meaningful amount of these proteins, though wheat flour typically runs higher (often 10% to 14% depending on the variety). That difference matters for baking, since wheat’s higher gluten content is what gives bread its stretch and chew, but it does not matter for safety. Even a small fraction of barley’s gluten content is enough to damage the intestinal lining in someone with celiac disease. The 20 ppm cutoff for “gluten-free” labeling translates to 0.002%, so barley at 7.2% is roughly 3,600 times above that limit.
Barley’s Protein Breakdown
Not all of the protein in barley is hordein. A study analyzing 35 barley cultivars found that the grain’s protein (averaging 11.2% of the grain by weight) breaks down into several categories. About 25% consists of albumins and globulins, which are water-soluble proteins that do not trigger gluten-related immune responses. The remaining 75% is made up of hordein subtypes: B and gamma hordeins account for about 45%, C-hordeins for 19%, and D-hordeins for 11%.
This matters because gluten testing kits were originally designed around wheat proteins, and they don’t always measure barley hordein accurately. Standard antibody-based tests tend to underestimate or inconsistently measure barley gluten, particularly in processed foods and beverages. The ratio of protein subtypes in barley differs from wheat in ways that throw off these tests, which is why researchers have called for newer mass spectrometry methods to replace older testing approaches for barley-containing products.
Hidden Barley in Processed Foods
Whole barley and pearl barley are easy to spot on a label, but barley-derived ingredients are widespread in processed foods and not always obvious. Malt extract, malt syrup, malt flavoring, and malt vinegar are all typically made from barley. The word “malt” on a label, without further qualification, almost always means barley malt. You’ll find these in breakfast cereals, granola bars, candy, salad dressings, and some soy sauces.
Current U.S. labeling law does not require manufacturers to call out barley the way they must call out wheat. Wheat is classified as a major food allergen, so any wheat-derived ingredient must be declared as “wheat” in the ingredients list or a “Contains” statement. Barley has no such requirement. An ingredient can legally appear as “malt extract” or “malt syrup” without disclosing that it comes from barley. A citizen petition currently before the FDA is pushing to change this, requesting that barley, rye, and oats be added to the major allergen list, a step already taken in more than 85 other countries.
If you are avoiding gluten, reading past the allergen statement and scanning the full ingredient list is essential. Look for any form of the word “malt” and assume it contains barley gluten unless the product is explicitly labeled gluten-free.
What About Beer and Fermented Barley?
Beer is the most common fermented product made from barley malt, and conventional beer contains gluten. The concentration varies widely. Testing of commercial beers has found gluten levels ranging from below 5 ppm (the detection limit) to over 100 ppm, depending on the brewing process and ingredients used.
Some brewers reduce gluten by using enzymes that break down hordein during brewing, or by partially replacing barley malt with rice, corn, or sugar. Beers treated this way may test below 20 ppm on standard tests, but there’s a significant catch: the antibody-based tests approved for measuring gluten perform poorly on fermented and hydrolyzed products like beer. The brewing process fragments hordein proteins in ways that make them harder for test kits to detect, even when immunologically active peptides may still be present. Research comparing antibody tests to mass spectrometry found no consistent relationship between the two methods when applied to beer.
Beers labeled “gluten-free” that are brewed from naturally gluten-free grains (sorghum, rice, millet) are a safer choice than “gluten-reduced” beers made from barley. The distinction between those two labels is important for anyone with celiac disease.
Barley’s Nutritional Upside for Non-Celiac Individuals
For people who tolerate gluten, barley is one of the more nutritious whole grains available. It is particularly rich in beta-glucan, a soluble fiber that lowers LDL cholesterol. The FDA approved a heart-health claim for barley products back in 2008, the same type of claim allowed on oatmeal packaging. Beta-glucan also slows the absorption of sugar after meals, which helps with blood sugar management.
Pearl barley, the most common form sold in grocery stores, has had its outer hull removed but retains much of its fiber. Hulled barley keeps the bran layer intact and offers more fiber and nutrients, though it takes longer to cook. Both forms contain gluten and are unsuitable for a gluten-free diet regardless of how they are processed or prepared. Cooking, soaking, or sprouting barley does not remove or deactivate its hordein proteins.