Explainers
Why food contains gluten
Eight mechanisms account for almost every "no" on this site. Each verdict page links up to the ones it rests on, so the reasoning is written once and checked once.
Why barley malt is in your cereal (and what it means)Malt is barley, barley is a gluten grain, and in the US barley never has to be named on the label, so "malt" is the whole warning you get.Certified gluten-free vs "no gluten ingredients"A certification means an audited 10 ppm; a gluten-free claim means an enforceable 20 ppm; a clean ingredient list means neither has been checked.Why distilled spirits are gluten-free even when made from grainGluten proteins are too large to evaporate, so they stay in the still, which is why grain whisky is gluten-free and grain beer is not.Modified food starch, and what US labelling law actually tells youOn an FDA-regulated US label, unqualified "modified food starch" is not wheat, but the same law lets barley hide inside "natural flavouOats, avenin, and why gluten-free oats existOats contain avenin, not gluten. The problem is the supply chain they travel through, which is why "gluten-free oats" is a real category.The shared fryer problemA naturally gluten-free food fried in oil shared with battered items is not gluten-free, measured contamination is unpredictable and sometimes far aboSoy sauce is made with wheatStandard brewed soy sauce is roughly half wheat by grain weight, which is why it turns up as the hidden gluten in food that has no obvious flour in itWhat 20 ppm actually means20 ppm is the legal ceiling for making a gluten-free claim, not a measure of what any individual can safely eat.