Allergen guide

Peanut in recipes — how Frittu checks and excludes it

Peanuts appear in many cuisines under different names — groundnut in West African and British cooking, arachis oil on pharmaceutical and specialty labels, satay in Southeast Asian dishes. This page explains what Frittu's system does, specifically, when peanut is listed as an excluded ingredient in a user's profile.

Peanut in everyday cooking

Despite the name, the peanut is not a tree nut — it is a legume that grows underground. Its culinary footprint, however, extends well beyond the roasted snack. Ground peanuts form the base of satay sauces across Thai, Indonesian, and Malaysian cooking. Peanut oil — high in monounsaturated fats and with a high smoke point — is a common choice for stir-frying, wok cooking, and deep-frying. In West African cuisines, groundnut stew is a staple dish built around a peanut-and-tomato base.

The naming variation adds complexity. In Britain and much of West Africa, peanuts are called groundnuts and the oil is sold as groundnut oil. On ingredient labels — particularly in pharmaceutical and specialty food products — peanut oil appears as arachis oil, the botanical name derived from the genus Arachis. In informal contexts, peanuts in shells are called monkey nuts; dry-roasted versions at bars and events are often called beer nuts. Mandelonas are a processed form: peanuts reshaped and flavoured to resemble tree nuts.

In recipe contexts, peanut most often appears as peanut butter (in sauces, baked goods, and dressings), peanut oil (as a cooking fat), satay sauce (as a named component), or as whole roasted peanuts in salads and noodle dishes. Each of these forms is covered by Frittu's keyword list.

How Frittu's allergen check works

When your profile lists peanut as an excluded ingredient, Frittu applies a two-layer check to every recipe it generates.

Layer 1 — prompt-side instruction.Before sending a generation request to Claude, Frittu builds an exclusion list from your allergen profile. For peanut, that list includes not just “peanut” but also the aliases most likely to appear in a recipe: groundnut, groundnut oil, arachis, arachis oil, satay, mandelonas, monkey nuts, and beer nuts. Claude receives these as a hard exclusion instruction and is directed to build the recipe without them.

Layer 2 — deterministic post-generation scan. After the recipe is returned, Frittu runs a server-side function that checks every ingredient name against a coded keyword list for peanut. If any ingredient name matches a peanut keyword, the recipe is rejected and the generation is retried automatically before the recipe reaches you. The rejection and retry happen server-side — the user sees only the final recipe that passed the check.

What this check does not cover. The check operates on ingredient names as generated. It does not cover cross-contamination that could occur during home preparation — shared cooking equipment or oils previously used with peanut-containing foods — nor does it account for ingredients a user adds themselves after receiving the recipe. Standard kitchen precautions remain relevant regardless of what a recipe generator produces.

Hidden sources of peanut in cooking

Common hidden sources of peanut in cooking include the following — ingredients that are peanut-derived or peanut-based but may appear in recipes without the word “peanut” being present.

Groundnut / groundnut oil — “Groundnut” is the British and West African term for peanut. Groundnut oil is widely used in West African cuisines — notably in groundnut stew — and in some Asian recipes where the high smoke point makes it a preferred frying oil. Recipes using this terminology would not be caught by a check that only scanned for “peanut,” so both “groundnut” and “groundnut oil” are in Frittu's keyword list.

Arachis oil — The botanical and pharmaceutical name for peanut oil, derived from the genus Arachis. It appears on ingredient labels for certain pharmaceutical preparations, some cosmetics, and specialty food imports, as well as in formal recipe ingredient lists that use the scientific name. A check scanning only for “peanut” would not catch “arachis oil,” so Frittu's keyword list includes “arachis” as a standalone term.

Satay — A Southeast Asian dish in which the dipping or marinating sauce is traditionally made from ground peanuts. Satay appears in Thai, Indonesian, and Malaysian cooking and is increasingly common in contemporary Australian and British menus. A recipe that calls for “satay sauce” contains peanuts but may not list them separately. Frittu's keyword list includes “satay” directly to catch this category.

Mandelonas — Peanuts that have been processed, reshaped, and flavoured to resemble tree nuts such as almonds or pecans. They can appear on charcuterie boards or in mixed-nut products where a person avoiding peanuts might not expect them. Frittu includes “mandelonas” in its keyword list so that any recipe referencing this ingredient is flagged and rejected.

Monkey nuts / beer nuts — Colloquial names for peanuts — “monkey nuts” typically refers to unshelled peanuts as sold in Britain and Australia; “beer nuts” refers to dry-roasted or honey-roasted peanuts common in North American contexts. Both terms appear in recipe ingredient lists, particularly in snack recipes, and are included in Frittu's keyword list.

Peanut oil — Widely used as a cooking and frying oil due to its high smoke point and neutral flavour. It is common in stir-fries, wok cooking, and deep-frying — appearing in many Asian and Southern American recipes. Some people with mild peanut sensitivity tolerate highly refined peanut oil because refining removes most protein; however, individual thresholds vary, and Frittu flags peanut oil regardless so that users can make their own assessment.

Frequently asked questions

How does Frittu's system check for peanuts in a generated recipe?

Frittu uses a two-layer process. First, before generating a recipe, Claude is given an exclusion list built from your allergen profile. For peanuts, that list covers the ingredient itself as well as its culinary aliases — botanical names like arachis oil, regional names like groundnut, condiment forms like satay sauce, and processed products like mandelonas. Claude is instructed to build the recipe without those ingredients. After the recipe is returned, a server-side function checks every ingredient name against a coded keyword list for peanut. Any match causes the recipe to be rejected and Frittu attempts to generate an alternative.

Why does Frittu check for "arachis oil" when excluding peanuts?

"Arachis oil" is the botanical and pharmaceutical name for peanut oil. It comes from Arachis hypogaea, the scientific name for the peanut plant. The term appears on food labels — particularly in pharmaceutical products, some cosmetics, and specialty food imports — and can also appear in formal recipe ingredient lists where the writer has used the scientific name. Because "peanut" does not appear in the name "arachis oil," a check that only scanned for "peanut" would miss it. Frittu's keyword list includes "arachis" to catch this form wherever it appears in a generated recipe.

What is "mandelonas" and why is it in the peanut keyword list?

Mandelonas are peanuts that have been processed, reshaped, and flavoured to resemble tree nuts such as almonds or pecans. They are a real cross-allergen risk: a person avoiding peanuts who encounters mandelonas on a charcuterie board or in a mixed-nut product could consume peanuts without realising it. Frittu includes "mandelonas" in its peanut keyword list so that any generated recipe referencing this ingredient is flagged and the recipe rejected before it is shown.

Does the satay keyword catch all peanut-based satay dishes?

The keyword "satay" flags any recipe containing the word satay in an ingredient name. Satay sauce is traditionally made from ground peanuts and is the defining component of satay dishes across Thai, Indonesian, and Malaysian cooking. Because the peanut content is in the sauce rather than listed as a standalone ingredient, a check that only scanned for "peanut" could miss a recipe that called for "satay sauce" by name. Frittu's keyword list includes "satay" directly so that this category of recipe is caught by the post-generation scan.

What happens when a generated recipe triggers the peanut check?

The recipe is rejected before it is saved or shown to the user. Frittu retries the generation automatically. The rejection and retry happen server-side — the user sees only the final recipe that passed the check. If a generated recipe matches a peanut keyword it is rejected and Frittu attempts to generate an alternative; if none passes the check, no recipe is returned for that slot.

What this check covers. Frittu's allergen check operates on ingredient names as generated by the recipe system. It covers the ingredients listed in the recipe. It does not cover cross-contamination from shared equipment during kitchen preparation, peanut residues in oils used for cooking other foods, or ingredients that a user adds to a recipe themselves after receiving it. The check also does not apply to user-added ingredients entered manually into the shopping list or meal planner outside of recipe generation.

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