Wheat and gluten

What a wheat allergy is, and what gluten is

Two different things share this page, and separating them is the first practical step. A wheat allergy is a reaction to wheat proteins. Gluten is a group of storage proteins found in wheat, rye and barley; coeliac disease is an immune reaction to gluten that damages the gut lining, and it is not a food allergy. The labelling systems treat them differently, and so do the claims on the front of the pack.

The result is that wheat free and gluten free are not synonyms and neither one is a superset of the other in practice. A rye loaf is wheat-free and full of gluten. A bar of pure barley malt has gluten and no wheat. Meanwhile a product labelled gluten-free is permitted to contain wheat-derived ingredients that have been processed until the gluten is gone — deglutinated wheat starch is the usual example — so gluten free does not guarantee no wheat. If wheat protein is your problem, the ingredient list is the thing to read, not the claim.

The names that do not say “wheat”

Wheat has more aliases than any other allergen, largely because the grain is ancient and every region named its own varieties and grinds.

Semolina is coarsely milled durum wheat; durum is the hard wheat used for pasta. Farina is another milled wheat, sold as a hot cereal. Graham flour is a wholewheat flour.

Spelt, farro, emmer, einkorn and kamut — kamut being a trade name for khorasan wheat — are all wheat species or varieties. They are marketed as ancient alternatives, which makes them the aliases most likely to be chosen deliberately by someone avoiding wheat.

Bulgur, couscous and freekeh are wheat that has been parboiled, rolled or roasted. Couscous is tiny pasta, not a grain in its own right.

Triticale is a wheat-and-rye hybrid, so it carries both.

Seitan is wheat gluten itself, washed free of starch and used as a meat substitute. It is the most concentrated form of the protein on any shelf.

Rusk is dried wheat bread, crumbed and added to British sausages, burgers and stuffings as a binder. The ingredient list may say only “rusk”.

Hydrolysed wheat protein names the grain; modified food starch does not. Starch may be maize, potato, tapioca or wheat, and only where the source has to be declared will you know which.

Malt, malt extract and malt vinegar are made from barley in the great majority of cases. Brewer’s yeast is often grown on a barley substrate and carries gluten with it. Both are gluten without being wheat, which is the gap the US rules leave open.

How the label is worded where you are

The EU and UK treat gluten cereals as a category and name its members — wheat, rye, barley, oats, including spelt and khorasan — and each must be emphasised inside the ingredient list, so semolina and seitan have to be shown as wheat. Several wheat- and barley-derived ingredients are named as exceptions and are exempt from declaration: wheat-based glucose syrups including dextrose, wheat-based maltodextrins, glucose syrups based on barley, and cereals used to make alcoholic distillates including agricultural ethyl alcohol.

The United States is narrower. FALCPA covers wheat alone, so the plain word wheat must appear, but barley malt and rye can sit in the list with no allergen statement at all. Outside both systems there may be no emphasis and no summary line, and the local variety name may be all that is printed.

Cross-contamination and “may contain”

Flour is a dust, which makes wheat unusually mobile. It hangs in the air of a bakery, settles on surfaces and coats shared equipment, and fryers, toasters, conveyors and mills carry it between products. That is why oats are an issue even though oats are not wheat. Precautionary wording — “may contain wheat”, “made in a bakery that handles wheat flour” — is voluntary and unstandardised nearly everywhere, and one phrase is not legally safer than another. Its absence is not evidence that no wheat came near. Loose bakery goods, deli counters and bulk bins have no ingredient list at all. PNut reports any such wording as May contain, and what “may contain traces” actually means explains why a flour warning is not a measurement of anything.

Reading a wheat label abroad

Three patterns matter abroad. The word for wheat changes — blé, trigo, Weizen, 小麦 — and French uses both blé and froment. The word for gluten is recognisable in most European languages but not in Chinese or Arabic script. And the flour and semolina words, maida, sooji, semola, irmik, Grieß, are what actually appear on South Asian, Mediterranean and Turkish packaging, often without the word wheat anywhere nearby. The table below covers all three, and reading a label in a language you don’t speak covers the paragraph they sit in.

How PNut flags wheat and gluten

Scan the barcode and PNut looks the product up and reads its published ingredient list; photograph the ingredient panel instead and it reads the text off the label, in any of 40+ languages. It checks for wheat, for the gluten cereals, and for every variety and grind name on this page, then returns one of four verdicts — Safe, Contains allergen, May contain, or Unknown when the label cannot be read. It says Unknown rather than guessing.