Allergen guide
Egg in recipes — how Frittu checks and excludes it
Egg turns up in everyday cooking well beyond obvious dishes — in dressings emulsified with yolk, in desserts built on whipped whites, and in processed foods that use egg proteins as binders. This page explains what Frittu's system does, specifically, when egg is listed as an excluded ingredient in a user's profile.
Egg in everyday cooking
Egg serves several different roles in cooking, and each one can appear in a recipe under a different name or form. The whole egg is used as a binder in meatballs, fritters, and baked goods. The yolk alone enriches sauces, curds, and pasta dough. The white, when whipped, provides structure in meringues, soufflés, and some mousse recipes. Egg wash is applied to pastry before baking to produce a golden glaze.
The less obvious appearances come through emulsified condiments. Mayonnaise is an oil-in-water emulsion stabilised by egg yolk lecithin — it appears in dressings, coleslaws, sandwich fillings, and some baked goods used as a moisture carrier. Aioli is a garlic-forward variant of the same emulsion. Both are common recipe ingredients that carry egg without naming it in the dish title.
Egg proteins also appear in processed and sports nutrition contexts. Albumen — the dried form of egg white — is used as a binder in some processed foods and as a clarifying agent in wine production. Albumin (an alternative spelling used in food labelling and nutrition products) refers to the same family of proteins. These are the forms most likely to appear under a name other than “egg” in a recipe ingredient list.
How Frittu's allergen check works
When your profile lists egg 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 egg, that list includes not just “egg” and “eggs” but also the aliases most likely to appear in a recipe: yolk, albumen, albumin, mayonnaise, mayo, meringue, and aioli. 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 egg. The check matches egg as a whole word, so ingredient names that merely contain those letters — such as eggplant — are not flagged. If a recipe still contains a matched keyword after generation, it is rejected and Frittu attempts to generate an alternative before showing you a result.
What this check does not cover. The check operates on ingredient names as generated. It does not cover egg introduced through shared cooking equipment, egg added by the user to a recipe after receiving it, or egg present in a manufactured product under a trade name not in the keyword list. If you prepare food for someone with a significant egg allergy, standard precautions around cross-contamination and label reading remain relevant.
Hidden sources of egg in cooking
Common hidden sources of egg in cooking include the following — ingredients that contain egg but may appear in a recipe without the word “egg” being visible.
Frequently asked questions
How does Frittu's system check for egg in a generated recipe?
Frittu uses a two-layer process. First, before generating a recipe, Claude is given an exclusion list derived from your allergen profile. For egg, that list includes not just "egg" but also the forms and derivatives most likely to appear in a recipe: yolk, albumen, albumin, mayonnaise, mayo, meringue, and aioli. 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 egg. Any ingredient name that matches an egg keyword causes the recipe to be rejected and the generation retried automatically before the recipe is shown to you.
Why doesn't Frittu flag eggplant as an egg-containing ingredient?
Frittu's post-generation check distinguishes "egg" as a standalone ingredient from words that merely contain those letters. Eggplant is not flagged because the check matches egg as a word, not as a fragment of a longer word. This is a deliberate design choice — without it, any ingredient whose name begins with the letters e-g-g would be incorrectly rejected.
Does aioli trigger the egg check?
Yes. Aioli is traditionally an emulsion of egg yolk, garlic, and oil — closely related to mayonnaise. The word "aioli" appears directly in Frittu's egg keyword list. Any recipe that calls for aioli as an ingredient is flagged and the generation retried when egg is excluded from a user's profile. Many commercial aioli products also contain egg in their listed ingredients, making this an important inclusion in the keyword list.
What happens when a generated recipe triggers the egg check?
The recipe is rejected before it is saved or shown to the user. Frittu attempts to generate an alternative; if none passes the check, no recipe is returned for that slot.
Does the check cover egg used as a binding or coating that might not be listed as "egg"?
The keyword list is designed to catch the most common disguised forms. Albumen and albumin are the egg white proteins — they appear in some sports nutrition products, processed foods, and wine-clarifying agents, and both are in Frittu's keyword list. Meringue is a flagged keyword that catches egg white in dessert and cake-decoration contexts. Aioli and mayonnaise catch emulsified egg yolk in dressings and condiments. Yolk catches the component form used in curds, sauces, and some enriched doughs. That said, the check operates on ingredient names as generated. If a user adds their own coating to a recipe after receiving it, or if a product ingredient label lists egg under a name not in the keyword list, that falls outside what the check can cover. Standard precautions around label reading and kitchen preparation remain relevant.
Try Frittu with your allergen list
Set your allergens once. Every recipe Frittu generates is then checked against them before it reaches you.
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