Tree nuts

What a tree nut allergy is

“Tree nut” is not a botanical category. It is a labelling category: a list of edible seeds and kernels that grow on trees and happen to cause a lot of reactions. The EU and UK name eight of them — almond, hazelnut, walnut, cashew, pecan, Brazil nut, pistachio and macadamia. That list is what the emphasis rules attach to, and it is narrower than the everyday word “nut”. A pine nut is a conifer seed and is not on it. A coconut is not on it either. Peanut is a legume and is regulated separately, which is the single most useful thing to know when reading a “free-from” claim.

The nuts on the list are also not interchangeable with one another. Cashew and pistachio are closely related; almond sits with peaches and cherries; walnut and pecan are a pair. Someone who reacts to one may be fine with the others, or may not be. So a label saying only “tree nuts” is less useful than one naming the nut, and it is worth reading which nut is there.

The names that do not say “nut”

Confectionery is where most of the aliases live, because the traditional names are older than allergen labelling.

Marzipan and almond paste are ground almond and sugar. They fill stollen, line fruit cake and appear inside chocolates with no other clue on the wrapper.

Frangipane is an almond cream baked into tarts — the sticky layer under the pears or the raspberries.

Praline is nut and caramel ground to a paste. In Belgium and France it is normally hazelnut or almond; in the southern United States pralines are traditionally pecan. The word alone does not tell you which nut.

Nougat is a whipped sugar confection that usually carries almonds or hazelnuts, and gianduja is the hazelnut-and-chocolate paste behind most chocolate hazelnut spreads and a great many filled chocolates.

Filbert and cobnut are both hazelnut. Filbert is the standard American trade word, so a US ingredient list may say filbert where a British one says hazelnut.

Queensland nut is macadamia. Pignoli, pinon and pine kernel are pine nut.

Natural nut extract and almond flavouring are usually derived from bitter almond kernels, though synthetic benzaldehyde is also used and the label rarely says which.

Mortadella is the trap that is not a word at all: the classic Bologna version is studded with pistachio, and on a deli counter there is no ingredient list to check.

Mandelonas run the other way. They are peanuts de-flavoured and soaked in almond flavouring, sold as a cheap almond substitute — a peanut sitting exactly where you would expect a tree nut.

How the label is worded where you are

In the EU and UK the eight named nuts must be picked out of the ingredient list so they stand apart from everything else, usually in bold. Because the rule attaches to the nut and not to the product name, marzipan has to declare almond and gianduja has to declare hazelnut. One category of exception is named in the rules: nuts used to make alcoholic distillates, including agricultural ethyl alcohol, are exempt from declaration altogether.

In the United States the requirement is that the specific nut be named in plain English, either in the ingredient list or in a “Contains” line beneath it. Elsewhere there may be no emphasis convention at all, and the confectionery name may be the only thing printed.

Cross-contamination and “may contain”

Tree nuts attract more precautionary labelling than almost anything else, and for a real reason: nuts are shelled, chopped, roasted and coated on shared equipment, and one line will run an almond product and a cashew one the same day. Wording such as “may contain nuts” or “packed in a facility that handles nuts” is voluntary in most places and is not standardised, so no phrase is legally safer than another. Its absence is not evidence that no nut was near the product. Loose bakery goods, pick-and-mix, ice cream counters and refilled bulk bins carry no ingredient list at all, and nut dust travels. PNut reports any such wording as May contain, and what “may contain traces” actually means is the longer answer on how much a nut warning tells you.

Reading a tree nut label abroad

Two things go wrong abroad. The umbrella term changes into something that does not resemble the English word — fruits à coque, frutta a guscio, Schalenfrüchte — and the individual nut names change too, so you are looking for a set of words rather than one. The second problem is that the emphasis convention you rely on may not exist, leaving the nut mid-list in the same weight as the sugar. The table below lists both the umbrella term and the common individual nuts, and reading a label in a language you don’t speak covers the list they are buried in.

How PNut flags tree nuts

Scan the barcode and PNut looks the product up and reads its published ingredient list; photograph the ingredient panel instead and it reads the text straight off the label, in any of 40+ languages. It checks the eight named nuts, the confectionery aliases on this page and the trade names, then returns one of four verdicts — Safe, Contains allergen, May contain, or Unknown when the label cannot be read. It says Unknown rather than guessing.