How do I cook safely for someone with coeliac disease?

Coeliac disease is an autoimmune reaction in which gluten causes the immune system to damage the lining of the small intestine. It is not an allergy, it does not usually cause an immediate dramatic reaction, and that is exactly why it gets treated too casually. The damage happens regardless, and the amounts involved are small enough that most contamination is invisible.

Safety

Step by step

1. Understand the amount that matters.Foods labelled gluten-free in the UK must contain no more than 20 parts per million of gluten. That is a very small quantity — a shared toaster, a wooden spoon used in a wheat sauce, or flour dust settling on a worktop can exceed it. A crumb is a meaningful amount here.
2. Cook their food first, always.Cleaned surfaces, clean equipment, before any bag of flour is opened or any bread is cut. Then cover the gluten-free food and put it aside before you start on anything else. This single ordering rule prevents most contamination.
3. Deal with the equipment that holds crumbs.A toaster is the classic problem — either a dedicated one or reusable toaster bags. Also: a colander used for wheat pasta, a wooden chopping board with knife grooves, a wooden spoon, a scratched non-stick pan, a flour sieve and a bread bin. These hold residue that washing does not fully remove.
4. Separate the shared jars.Butter, spreads, jam, peanut butter, chutney and mayonnaise all get contaminated by a knife that has been in wheat bread. Keep a separate labelled tub of each, or use squeezy bottles.
5. Never share frying oil or pasta water.Chips fried in oil that has cooked breaded food are not gluten-free. Gluten-free pasta cooked in water that has boiled wheat pasta is not either. Fresh oil, fresh water, separate pans.
6. Watch out for flour dust.Flour hangs in the air for a long time and settles on every surface in a kitchen. If you have been baking, that kitchen is not safe for gluten-free preparation until the surfaces have been wiped down properly. Bake after, not before.
7. Learn where gluten hides.Stock cubes and gravy granules, soy sauce, most sausages and burgers, ready-made sauces, some crisps, malt vinegar and malt extract, beer and ales, communion wafers, some medications, and anything dusted or thickened with flour. Barley, rye and spelt all contain gluten. Wheat-free does not mean gluten-free.
8. Treat oats as a separate question.Oats do not contain gluten but are almost always contaminated by wheat during growing and milling, so only oats specifically labelled gluten-free are suitable. A minority of people with coeliac disease also react to avenin in oats themselves, so follow that person's own guidance.
9. Read the label every single time.In the UK, cereals containing gluten must be emphasised in the ingredients list, usually in bold. Look for the crossed grain symbol or a gluten-free claim. Recipes change without notice, so a product that was safe last time still gets checked.
10. Keep the packaging until the meal is finished.It allows anyone to check what was in a dish, and it matters if someone becomes unwell afterwards.

Tips

• Coeliac UK is the reference organisation and publishes an up-to-date food and drink directory, which is far more reliable than working it out from labels alone.
• Naturally gluten-free meals are easier than substituted ones — rice, potatoes, meat, fish, eggs, pulses, vegetables. Building the meal from those avoids most of the problem.
• Gluten-free flours behave differently in baking, and a blend with xanthan gum will get you far closer than a single flour.
• In restaurants, say 'coeliac' rather than 'gluten intolerant'. Kitchens treat the two very differently and coeliac is understood as a medical requirement.

Common mistakes

• Picking gluten-containing items off a dish and serving the rest — Removing croutons, batter or a bread roll leaves gluten behind in the sauce, the oil and on the food itself. It is well above the amount that causes damage, and it is one of the most common well-meaning errors.
• Assuming no immediate reaction means no harm — Many people with coeliac disease have few or no immediate symptoms while the damage to the gut lining continues. It is why the rules cannot be relaxed based on how someone felt afterwards.
• Treating it as a fashionable dietary choice — The rise of gluten-free eating by preference has made kitchens and hosts more casual about it, which is precisely the wrong direction for someone with an autoimmune condition. Say coeliac, and treat it as medical.

Questions people ask