Build an allergen matrix that stays correct

An allergen matrix is a grid that shows, for every dish on the menu, which allergens it contains. Dishes run down one side, allergens across the top, and each cell says yes or no. It sounds like paperwork, and in a sense it is. It is also the record a server reaches for when a guest says "I have a sesame allergy, what can I eat?", and the record that decides whether the answer is right.

Most kitchens have an allergen matrix of some kind. The problem is keeping it correct. Menus change, recipes are adjusted, suppliers swap one product for another with a slightly different label, and a garnish is added at the pass because it looks better. Each change can alter a dish's allergens, and each one has to reach the matrix before the next guest asks. A matrix that was right in March can be quietly wrong by May.

This guide sets out how to build an allergen matrix that stays correct: what it should contain, where the information comes from, the two kinds of ingredient that catch kitchens out most often, how to update it when anything changes, how to use it at the table, and how to check it. It is practical guidance rather than legal advice; the rules on allergen information vary by country, so check what applies where you trade.

An allergen matrix lists every dish against every allergen you are required to declare, and marks which allergens each dish contains. In the UK and the EU, that usually means the 14 allergens set out in food information law: celery, cereals containing gluten, crustaceans, eggs, fish, lupin, milk, molluscs, mustard, tree nuts, peanuts, sesame, soya, and sulphur dioxide and sulphites. Other countries have their own lists, which overlap heavily but are not identical.

A good matrix goes further than ticks. It records which component of the dish carries each allergen, so a server can say "the sesame is in the dressing, and we can leave it off", and it notes when a dish can be adapted. It is dated, so everyone knows which version they are reading. And it is kept somewhere the whole team can reach during service.

The matrix is not a substitute for a conversation with the guest. It is what makes that conversation accurate. Our guide to menu design covers how allergen and dietary information fits on the menu itself.

Matrices rarely go wrong because someone filled them in carelessly on day one. They go wrong because the world changes around them. A recipe is tweaked, a supplier substitutes a product, a new chef makes a dish slightly differently, or a seasonal special is added without being entered. Each change is small, and each one is easy to forget.

The second reason is distance. The matrix is often kept by a manager in an office, while the changes happen in the kitchen. Unless there is a clear route from the change to the record, the record falls behind.

The third is format. A matrix kept as a printed sheet, a spreadsheet and a separate version on the QR menu is three records, not one. When they disagree, nobody knows which is right, and the server at the table has to guess. Our guide to updating the menu in one place, not five covers why every copy of the menu, including its allergens, should come from one source.

The most reliable allergen matrix is built from recipes, not from memory. For each dish, write down every component: the base, the sauce, the garnish, the dressing, the oil it is cooked in and anything added at the pass. For each component, list its ingredients. For each ingredient, record its allergens from the product label or the supplier's specification.

That chain, from dish to component to ingredient to label, is what keeps the matrix honest. It means the allergen and recipe data live together, and when a recipe changes, you can see exactly which allergens might change with it. A matrix built from the chef's recollection of what is in a dish is only as good as that recollection on the day it was written.

Keep the specifications on file. When a supplier changes a product, the new specification is the evidence for the new allergens. Without it, the matrix is a guess.

Two kinds of ingredient are easy to miss, and between them they account for many of the surprises in an allergen matrix.

The first is the compound ingredient: anything bought in that is itself made of several ingredients. Stock powders, sauces, spice blends, dressings, breads, sausages and desserts all fall into this group. Their labels can list allergens that nobody would expect: celery in a stock, mustard in a dressing, milk in a spice mix, nuts in a pesto. And their recipes can change when the manufacturer changes them, without anyone in the kitchen noticing.

The second is the finishing touch: the garnish, oil, dressing, crumb or sauce added at the last moment. A drizzle of sesame oil, a scatter of toasted nuts, a spoon of crème fraîche or a sprinkle of crispy shallots fried in a shared fryer can add an allergen to a dish whose recipe says nothing about it. These touches are often added by whoever is on the pass, which is why they slip through.

To catch both, read every compound ingredient's label when it arrives, not only when it is first bought, and write every finishing touch into the recipe, however small. If it goes on the plate, it goes in the recipe.

Once the recipes are written, building the grid is straightforward. List every dish, every side and every sauce served separately down the side. List every allergen you must declare across the top. Mark each cell from the recipe chain: yes, no, or "may be adapted", with a note of which component carries the allergen.

Include drinks if they contain allergens. Cocktails can contain eggs, milk, nuts or sulphites, and a matrix that covers only food leaves the bar to improvise. Include the kids' menu, the brunch menu and any set menus as well.

Date the matrix and give it a version number. Every printed copy should show the date, so anyone reading it knows whether it is current. When the matrix changes, the old copies should be removed, not left in a drawer to be found during a busy service.

Dietary labels, such as vegetarian, vegan, gluten free or halal, are different from allergen declarations, and the matrix should keep them separate. A dish can be vegetarian and contain milk and eggs. A dish described as gluten free has to meet a standard that goes beyond leaving out the bread; cross-contact matters too.

Use dietary labels carefully and consistently. Define each one once, apply it only when the dish genuinely meets it, and record the reason in the recipe. If a dish is vegan except for a garnish that can be left off, say so in the matrix rather than labelling it vegan.

Guests use dietary labels and allergen information together, so they should agree. A vegan label on a dish whose matrix says it contains milk is the kind of contradiction that causes harm and destroys trust.

An allergen matrix records what is in a dish. It does not, on its own, record what might get into it. Shared fryers, shared boards, shared utensils, flour in the air and sauces stirred with the same spoon all create a risk of cross-contact that the recipe cannot show.

Be honest about the kitchen you have. If the fries are cooked in the same oil as battered fish, the fries are not suitable for a guest with a fish allergy, whatever their recipe says. If every dish is prepared in a small kitchen where nuts are used, say so. Many venues add a clear note to the matrix and the menu about the risk of cross-contact, and train staff to explain it.

Food safety systems, such as a HACCP plan, are where cross-contact controls usually live. The Food Standards Agency's guidance on HACCP is a useful starting point for building allergen controls into the kitchen's routines rather than relying on memory.

The matrix stays correct only if every change reaches it. Write down the triggers that require an update, and make the update part of the change itself:

Make one person responsible for the matrix, and make the update a step in the change, not a task for later. A new dish is not ready for service until its recipe and allergens are in the matrix and the floor team has been briefed. A substitution is not allowed until someone has checked the substitute's label.

Substitutions deserve special care. On a busy day, it is tempting to use whatever is in the store when a product runs out. If the substitute carries different allergens, the matrix is wrong from that moment. Agree in advance which substitutes are safe, and require a check for anything else.

The matrix only protects guests if it is used. Every server should know where it is, how to read it and when to involve the kitchen. When a guest mentions an allergy, the server should check the matrix, confirm with the kitchen for anything unclear, and make sure the allergy is clearly marked on the order so the cook preparing the dish sees it.

Train staff to take allergies seriously without making guests feel like a problem. A calm "thank you for telling us, let me check exactly what we can do" is reassuring. A guess, or "it should be fine", is not. Our guide to allergen rules and the conversation at the table covers that conversation in detail.

Make sure the information reaches the kitchen in a form that cannot be missed. A verbal message shouted down the line is easily lost; an allergy printed clearly on the ticket travels with the order to the cook who prepares it.

A digital menu can make allergen information easier to use. Guests can filter dishes by the allergens they need to avoid, see each dish's allergens before they order and confirm that they have read the information. That helps guests with allergies find suitable dishes without reading every description, and it gives servers a starting point for the conversation.

It also raises the stakes for accuracy. A filter that shows a dish as safe when it is not is worse than no filter, because guests may trust it without asking. The digital menu's menu allergens must come from the same record as the matrix, and change when it changes.

Keep the human check in place. Even with a digital menu, encourage guests with allergies to speak to a member of staff, and make sure staff confirm with the kitchen. The digital menu supports the conversation; it does not replace it.

Check the matrix regularly against reality. Once a month, pick a few dishes and trace each one from the plate back to the labels: watch it being prepared, list every component and finishing touch, and compare the result with the matrix. Check the labels on the shelf against the specifications on file.

Look especially at dishes that have changed recently, specials, and anything with a bought-in compound ingredient. These are where errors are most likely. Record each check, what you found and what you corrected.

Ask the team too. Cooks often know about small changes that never reached the recipe: a different oil, an extra garnish, a substitute product used last week. A short conversation during each check finds these before a guest does.

A correct matrix is only half the job; the team has to know how to use it under pressure. Make allergen training part of every new starter's first week, before they serve a guest on their own. Show them where the matrix is, how to read it, which dishes can be adapted and when to go to the kitchen.

Practise the conversation. A short role-play, in which one person plays a guest with an allergy and another takes the order, shows quickly who is confident and who would guess. Repeat it whenever the menu changes, and include the kitchen team, who need to know how allergy orders reach them and what to do when they are unsure.

Keep a record of who has been trained and when. When the menu changes, brief everyone on the new dishes' allergens before the first service, and update the record.

Groups with several venues face an extra risk: the same dish can carry different allergens at different sites. One kitchen buys its bread from a different baker, another uses a different stock, a third adds a garnish the others do not. A single group matrix that assumes every site is identical can be wrong at some of them.

Either keep one matrix per venue, or make the shared matrix specify the exact products each venue must use, and check that they do. When a supplier differs by site, the matrix must differ too. The same discipline applies to substitutions, which are often made locally without anyone at the centre knowing.

Here is an illustrative case of how an allergen matrix goes wrong and how it is caught. The dish and details are examples.

The matrix was wrong for a month, and the human check caught it. The lasting fix was simple: every finishing touch written into the recipe, and a regular trace from plate to label.

In servearound, every dish carries its allergens, dietary tags and ingredients on the item itself, which is the information an allergen matrix records. Because a dish lives in one library and appears on every menu from there, the allergens a guest sees on the QR code menu come from the same record the team uses, and change when it changes.

Guests can filter the menu to show only what suits them or to avoid an allergen, and before ordering they confirm they have read the allergen information. A note on any dish reaches the kitchen, and a guest's allergy is called out on the kitchen ticket, where the cook preparing the dish will see it. The recipes, labels and checks behind the matrix are still the kitchen's responsibility. See the menus module, or get in touch to see how allergens appear on your menu.

It depends on where you trade. In the UK and the EU, there are 14 allergens set out in law. Check the rules in your own country, and the guidance your food safety authority publishes.

Every time a recipe, supplier or product changes, at the moment it changes. Check it against reality at least once a month.

The menu usually carries a clear statement about allergens and how to ask. The full matrix is often kept for staff to show guests on request, or on a digital menu.

Be very careful. Cross-contact in a shared kitchen makes absolute claims risky. Say what the dish contains and explain the cross-contact risk honestly.

One named person, usually the head chef or kitchen manager, with the authority to stop a change until the matrix is updated.

Include them. Cocktails and some wines and beers contain allergens, and the bar needs the same information as the kitchen.

An allergen matrix is a grid of every dish against every allergen you must declare, and it is only useful if it stays correct. Build it from recipes and labels rather than memory, record which component carries each allergen, and keep allergen and recipe data together so changes show up.

Watch the two kinds of ingredient that catch kitchens out, compound ingredients and finishing touches, keep dietary labels separate, and be honest about cross-contact. Update the matrix as part of every change, make sure allergies reach the kitchen on the ticket, keep one record behind every menu, and trace dishes from plate to label every month. Food safety depends on it.