Barley tea is not gluten free. Barley is one of the three primary gluten-containing grains alongside wheat and rye, and traditional barley tea, made by steeping roasted barley grains in water, contains gluten proteins called hordeins. If you have celiac disease or a gluten sensitivity, barley tea in any of its common forms (Japanese mugicha, Korean boricha, or loose roasted barley) is not safe to drink.
Why Roasting Doesn’t Remove the Gluten
A reasonable assumption is that roasting barley at high temperatures might break down or destroy gluten proteins. Research on this tells a more complicated story. When barley grains undergo dry heating (like oven roasting at 100°C), the hordein proteins show no measurable reduction even after two hours. Wet heating, such as steaming, does reduce the extractability of one type of hordein (B-hordein) over time, but another type (C-hordein) remains unchanged even after 120 minutes of steaming.
What’s happening at a molecular level is that heat causes some hordein proteins to bond together and become less soluble, not that they disappear. The proteins are still present in the grain. When you steep roasted barley in hot water to make tea, some of those proteins leach into the liquid. The roasting process changes solubility, not safety.
What FDA Rules Say About Barley
Under FDA labeling rules, a product cannot be labeled “gluten-free” if it contains any type of barley or an ingredient derived from barley that hasn’t been processed to remove gluten. Even barley-derived ingredients that have been processed must test below 20 parts per million (ppm) of gluten to qualify. Standard barley tea has not undergone any gluten-removal process, so it cannot legally carry a gluten-free label in the United States.
The National Celiac Association explicitly lists barley seed tea, boricha, and malted tea in its “contains gluten” category. Clinical research in the Postgraduate Medical Journal found barley to be harmful to celiac patients, with its toxic effect produced more readily than that of oats. The recommendation from that study was clear: exclude barley from the celiac diet entirely.
Barley Grass Tea Is Different
There’s one important distinction worth knowing. Barley grass, the young green shoots of the barley plant harvested before the grain develops, is not the same as the mature barley grain. The National Celiac Association notes that the young grasses of wheat and barley plants do not contain the same gluten proteins found in the mature grains. Some barley grass teas and powders are marketed as gluten-free for this reason.
The catch is cross-contamination. If barley grass is harvested too late, even small seed heads forming on the plant can introduce gluten. Unless a barley grass product is tested and certified gluten-free, there’s a real risk it contains trace amounts of grain protein. For people with celiac disease, this is a gamble that may not be worth taking.
Hidden Barley in Other Teas
Barley doesn’t only show up in products labeled as barley tea. Some herbal tea blends and flavored teas include roasted barley as an ingredient, sometimes without making it obvious on the front of the package. Barley malt can also hide in flavorings. If the source of a flavoring isn’t disclosed on the label, it’s worth contacting the manufacturer before assuming a tea is safe.
Any tea blend listing “roasted barley,” “barley malt,” or “malted barley” among its ingredients contains gluten. Pure teas made from the Camellia sinensis plant (black, green, white, oolong) are naturally gluten free, as are most single-ingredient herbal teas like chamomile, peppermint, and rooibos.
Gluten-Free Alternatives With a Similar Taste
If you enjoy barley tea’s toasty, nutty flavor, several naturally gluten-free options come close. Buckwheat tea (sobacha) is gluten free despite its name, since buckwheat is a seed, not a grain related to wheat. It has a nutty, earthy flavor that’s the closest match to barley tea’s roasted character. Roasted corn tea (oksusu-cha), popular in Korea, offers a mildly sweet, nutty taste and is made from a naturally gluten-free grain. Roasted brown rice tea (genmaicha, when sold without added barley) is another option with a warm, toasted profile, though you should check the label since some versions blend in roasted barley.