How to build an allergen matrix for a restaurant menu or deli counter

A guest tells your waiter she is allergic to peanuts and asks whether the chicken curry is safe. The waiter asks the kitchen, the cook says “I think so”, and everyone hopes. An allergen matrix for restaurant menu items replaces “I think so” with a written answer that comes from recipes and labels, not from memory.

This is how we build one with kitchens and deli counters, and how to keep it honest once it is on the wall.

What an allergen matrix is and who uses it

An allergen matrix is a table. Every dish or product you sell runs down the side, the allergens run across the top, and each cell says whether that allergen is present in the dish. That is all it is, but it does three jobs:

• Front of house uses it to answer a guest’s question accurately and quickly.
• The kitchen uses it to see which dishes need special handling when an allergy order comes in.
• Management uses it as the single reference that must be updated when a recipe or supplier changes.

For the allergen columns, use South Africa’s labelling regulations (R146) as your reference. R146 defines the common allergens that must be declared on prepacked food: egg, milk, crustaceans and molluscs, fish, peanuts, soya, tree nuts and cereals containing gluten (wheat, rye, barley and oats). These are also the allergens your suppliers’ labels will declare, which makes the matrix easier to build. Guests also ask about sesame, mustard, celery or sulphites, which are not on the R146 list. You can add columns for them, but only if you check them as carefully as the rest, and be clear which ones you track and which you do not.

Start from recipes and labels, not memory

The most common mistake we see is a matrix written by the chef from memory in one afternoon. It looks complete, and it is wrong in five places. Memory forgets the stock powder, the marinade and the brand of mayonnaise that changed in March.

Build it this way instead:

1. Get a written recipe card for every dish, including sub-recipes: sauces, dressings, marinades, spice mixes, batters and bases.
2. List every ingredient on each card, down to the oil, the garnish and the dusting flour.
3. For each bought-in ingredient, find the current label or supplier specification. Read the ingredient list and the allergen declaration.
4. Note any precautionary “may contain” statements separately from ingredients that are actually in the product.
5. Roll the allergens up from each ingredient to the sub-recipe, and from the sub-recipe to the dish.

If you cannot find a label or specification for an ingredient, the honest entry in the matrix is “unknown”, not “free from”. Then go and get the specification from the supplier.

Sauces, oils, garnishes and fryers: the hidden sources

The main ingredient of a dish is rarely the problem. The allergen hides in what goes on, under or around it. On audits we regularly find:

• Sauces and gravies thickened with wheat flour, or made with stock powders that contain milk or soya.
• Soy sauce and Asian-style marinades, which usually bring both soya and wheat.
• Pesto and dukkah, which often contain nuts, and crunchy salad toppings made with nuts.
• Butter used to finish vegetables or baste steaks on a dish the menu describes as plain.
• Egg wash on pastries, and egg in batters and some mayonnaise-based dressings.
• Shared fryers. Chips fried in the same oil as crumbed fish or battered calamari can pick up fish, mollusc and gluten traces.
• Shared griddles and boards, where a cheese toastie was made just before a “dairy-free” wrap.

Shared equipment is not an ingredient, so it never appears on a recipe card. Walk the line with the cook for each dish and ask: what does this touch on its way to the plate?

Laying out the allergen matrix for restaurant menu items

Keep the layout plain so a waiter can read it at a glance during a busy service. A section of a matrix might look like this:

Dish	Egg	Milk	Fish	Crustaceans and molluscs	Peanuts	Tree nuts	Soya	Gluten
Grilled chicken, chips, salad		Contains (basting butter)	Shared fryer	Shared fryer				Shared fryer
Beef curry and rice		Contains (cream)			May contain (spice mix)			Contains (stock)
Calamari strips	Contains (batter)		Shared fryer	Contains				Contains (batter)

A few rules make it work:

• Use three clear entries only: contains, may contain or shared equipment, and blank for not present.
• Say where the allergen comes from in brackets. It helps the kitchen offer a safe swap, such as chips from a dedicated fryer or no butter on the chicken.
• Put the date and version number at the top, and the name of the person who approved it.
• Keep one master copy. Printed copies at the pass and the till are controlled copies and are replaced, not hand edited.

Supplier and recipe changes: keeping it current

A matrix is only right on the day it was checked. After that, it drifts. The risky moments are predictable:

• a supplier is out of stock and sends a substitute brand;
• a supplier changes their recipe without telling you;
• the chef tweaks a special and it becomes a permanent menu item;
• a new menu goes live and the old matrix stays on the wall.

Build the check into receiving. When a delivery arrives with a different brand or a changed label, the receiver sets it aside and calls the chef or manager before it goes into the store room. The chef reads the label, updates the matrix if needed, and only then releases the product. For new dishes, the matrix is updated before the dish goes on the menu, not after.

A worked example. A deli and bakery in Pretoria changed its chicken basting sauce when the usual supplier ran short. The substitute contained soy sauce, so it brought soya and wheat. The receiver noticed the different label, put the bottles on a separate shelf and phoned the manager. The manager updated three lines on the matrix, briefed the counter staff at the next shift start and kept the old label in the file for reference. Ten minutes of work, and the “gluten-free roast chicken” sign came down before anyone with coeliac disease ate it.

Review the full matrix at least whenever the menu changes, and spot check a few dishes against current labels during your internal food safety audits.

Front of house: using the matrix to answer a guest

A good matrix is wasted if the waiter guesses. Train front of house to follow the same steps every time:

1. Listen and write it down. Which allergen, and how severe? A guest who says “even a trace makes me ill” needs a different answer from one who simply prefers to avoid dairy.
2. Check the matrix, not your memory. Read the line for the dish the guest wants.
3. Speak to the kitchen in person. Tell the chef or the person in charge of the pass, and mark the order clearly.
4. Tell the guest what you found, including any “may contain” or shared equipment risk.
5. Deliver the dish separately and confirm it at the table.

The most useful sentence a waiter can learn is: “Let me check the allergen chart and confirm with the chef before I answer.”

When you cannot guarantee a dish is free from an allergen

Most small kitchens share fryers, boards, ovens and hands. You often cannot promise that a dish has had no contact at all with an allergen, and you should not try to. What you can do is be honest:

• Never write “allergen free” or “safe for allergies” on a menu unless you have the separate equipment, storage and procedures to back it up.
• Tell the guest exactly what the risk is: “The dish does not contain nuts, but our desserts are made in the same area as nut products, so we cannot guarantee it is free from traces.”
• Let the guest decide with full information. Do not talk them into a dish to save the sale.
• If the risk is too high for a guest with a severe allergy, say so and suggest a dish you can control, such as one cooked in a cleaned pan with sealed ingredients.

For more on the kitchen controls that sit behind the matrix, see our allergen management support. To train your chefs, counter staff and waiters on building and using the matrix, our allergen management course for food service, retail and catering walks through it step by step.

What to do this week

• Collect a written recipe card for every dish and sub-recipe on the current menu.
• Pull the current label or specification for every bought-in ingredient.
• List shared fryers, grills, boards and ovens for each dish.
• Draft the matrix with the R146 allergens across the top and date it.
• Add a “different brand or label” check to your receiving procedure.
• Run a ten minute briefing with front of house on the five steps for answering a guest.