Where celery hides
The celery stick is the easy bit.
The difficult celery is the celery somebody used because it makes food taste better.
Celery contributes savoury flavour and is frequently used as a base ingredient rather than the star of a dish.
The Food Standards Agency specifically notes celery in forms including stalks, leaves, seeds and celeriac, and identifies foods such as celery salt, salads, some meat products, soups and stock cubes. Anaphylaxis UK adds examples including sauces, stocks, bouillons, seasonings, stews, tomato juice, sandwiches, crisps, spice mixes, batter for frozen foods and some cured bacon.
Rather than memorising a frightening list, it is better to understand why celery is there.
The soup problem
Many savoury dishes begin long before the ingredient named on the menu enters the pan.
A cook may start with finely chopped aromatic vegetables.
In French cooking, mirepoix traditionally combines onion, carrot and celery.
Italian soffritto commonly uses a similar aromatic base, although recipes vary.
These vegetables are gently cooked to create the underlying flavour on which soups, stews, sauces and braises are built.
By the time the finished food reaches the table, the celery may be:
soft;
blended;
strained;
covered by stronger flavours;
or completely invisible.
The diner sees:
beef stew.
The cook remembers:
onion + carrot + celery → then beef stew.
That is why soups and stocks deserve particular attention for celery allergy.
Celery is often part of the architecture of the flavour, not something intended to be noticed.
Stock cubes and bouillon
Stock is another classic hiding place.
A stock cube or bouillon powder can contain celery or celery-derived seasoning.
That stock may then become an ingredient in:
gravy;
soup;
risotto;
sauce;
casserole;
pie filling;
or countless other dishes.
This creates an ingredient inside an ingredient.
The restaurant's mushroom sauce may contain no visible celery.
But the stock used to make it may.
Fortunately, in the UK, celery's status as a regulated allergen means its deliberate presence cannot simply disappear legally into a generic flavouring without appropriate allergen information where the rules apply.
In a restaurant, however, somebody still needs to check the specification of the stock rather than guess from the finished dish.
Celery salt isn't just salt
The name sounds almost harmless.
Celery salt is commonly made using salt combined with ground celery seed or celery-derived flavouring, although formulations vary.
For somebody with celery allergy, the important word is therefore not salt.
It is celery.
Celery salt can be used in seasoning blends and savoury foods where there is no visible vegetable at all.
It is also famously associated with tomato-based drinks and cocktails such as a Bloody Mary.
So a person can encounter celery without a stalk, leaf or root appearing anywhere near the finished food.
This is one of the most useful things to explain to restaurant staff:
celery seed and celery salt count too.
Celeriac is the one people forget
Celeriac deserves repeating because its appearance is so different.
It can be:
roasted;
mashed;
puréed;
used in soup;
shredded raw into salads such as celeriac remoulade;
or substituted for potato in various dishes.
Someone may conscientiously avoid celery sticks and then order a celeriac purée without realising the relationship.
The FSA explicitly includes celeriac under celery for allergen purposes.
If you have celery allergy, celeriac is not a loophole.
Celery seed can be more difficult to recognise than celery
Celery seed is used as a spice.
Once ground into a seasoning mix, its botanical origin may be visually impossible to identify.
This creates the same practical lesson we encountered with mustard:
recognising the whole food is not enough.
Allergic consumers need reliable ingredient information because food processing destroys visual clues far more effectively than it necessarily destroys allergenic proteins.
UK labels give celery an important advantage
Celery is one of the 14 allergens for which UK food law requires specific allergen information when it is used as an ingredient.
For prepacked food, allergenic ingredients must be emphasised in the ingredients list — commonly using bold type, although other methods of emphasis are possible.
The requirement also applies to relevant additives, processing aids and other substances present in the final product.
So an ingredients list might contain:
vegetable stock (water, onion, carrot, CELERY, herbs...)
The important habit is still to read the whole ingredients list, not simply scan familiar packaging.
Recipes change.
And online information can lag behind the physical product.
EatSafe's general Shopping and Checking Food Information guide covers that problem in more detail.
Processing can make celery harder to see without making it irrelevant
A raw celery stalk is difficult to mistake for anything else.
Process it and the situation changes.
Dice it finely into a mirepoix.
Purée it into soup.
Dry it.
Grind celery seed.
Mix celery powder into seasoning.
Turn it into celery salt.
Incorporate celery into stock.
Now the ingredient may be impossible to identify visually.
This is one reason celery deserves its place among the regulated UK allergens despite many British consumers rarely thinking of it as an allergy risk.
Celery is not merely something eaten as a stick.
It is a flavour-building ingredient.
Celery juice and fashionable health foods don't get an exemption
Celery juice has periodically been promoted as a wellness drink.
For somebody with celery allergy, juicing does not transform celery into something immunologically unrelated.
The proteins originate from the same plant.
Likewise, celery powders, concentrated vegetable products and "green" drinks should not be assumed safe because they are marketed as natural, cleansing or healthy.
As we discovered with mustard:
"Healthy" is not an allergen category.
UK labels give celery an important advantage
Celery is one of the 14 allergens specifically covered by UK food-information rules.
For prepacked food, when celery is used as an ingredient and falls within the applicable allergen-declaration requirements, its presence must be indicated and emphasised in the ingredients information.
So a product might list:
Ingredients: Tomatoes, onions, carrots, CELERY, herbs...
or a compound ingredient might reveal celery within stock or seasoning.
This protection matters enormously precisely because celery can disappear so thoroughly into processed foods.
A shopper does not have to infer from the taste of a soup that somebody probably started with mirepoix.
The label is supposed to tell them.
Celery includes more than the stalk for labelling purposes
The legal allergen category is not limited to familiar green celery sticks.
The regulated category covers celery and products thereof, subject to the relevant legal framework and exemptions.
That is why celeriac, celery seed and celery-derived ingredients cannot simply escape allergen consideration because they look different from a stalk.
This is one of the most useful things a newly diagnosed person can learn:
Allergen law generally follows the biological ingredient more intelligently than supermarket shelving does.
Celeriac may sit with root vegetables.
Celery seed may sit with spices.
Celery salt may sit with seasonings.
For allergy purposes, the relationship remains.