Allergen guide

Gluten in recipes — how Frittu checks and excludes it

Gluten is a protein found in wheat and related grains. It turns up in dozens of everyday cooking ingredients — sometimes in places you would not expect. This page explains what Frittu's system does, specifically, when wheat or gluten is listed as an excluded ingredient in a user's profile.

Gluten in everyday cooking

Gluten is formed when two proteins in wheat — glutenin and gliadin — bond with water. It gives bread its spring, pasta its bite, and pastry its structure. That structural role means wheat flour turns up as a thickener, coating, or binder in many dishes where you might not immediately look for it: gravies, tempura batter, some salad dressings, and certain fried foods.

The grains that contain gluten extend well beyond modern wheat. Spelt, kamut, einkorn, and emmer are ancient wheat relatives that all contain gluten. Barley provides the base for malt vinegar and many beers. Rye is used in Scandinavian and Eastern European baking. Triticale is a wheat-rye hybrid. Farro — a name applied loosely to spelt, emmer, or einkorn — and freekeh (roasted green wheat) are increasingly common in restaurant-style grain dishes and salads. None of these are alternative grains in the sense of avoiding gluten; they are wheat or wheat relatives.

Fermented and processed products add another layer. Most commercially sold soy sauce is brewed with wheat as a fermentation substrate. Panko and standard breadcrumbs are made from wheat bread. Seitan is concentrated wheat gluten marketed as a meat alternative. Couscous is a pasta product made from semolina. These are the categories where gluten most often appears unexpectedly in a recipe.

How Frittu's allergen check works

When your profile lists wheat or gluten 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 wheat, that list includes not just “wheat” and “flour” but also the aliases most likely to appear in a recipe: soy sauce, spelt, barley, rye, panko, couscous, semolina, seitan, atta, maida, farro, freekeh, and others. 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 wheat. The check matches ingredient names carefully to avoid false positives — for example, ingredient names that contain wheat-flagged substrings but refer to non-wheat products (such as rice noodles or corn tortillas) are distinguished from wheat-based forms by examining what precedes the flagged term. 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 cross-contamination that could occur during home preparation — shared cutting boards, cookware, or oil used for wheat-containing foods — nor does it account for ingredients a user adds themselves after receiving the recipe. If you prepare food for someone with coeliac disease or a significant wheat sensitivity, kitchen cross-contamination controls remain your responsibility.

Hidden sources of gluten in cooking

Common hidden sources of gluten in cooking include the following — ingredients that contain gluten but may appear in a recipe without the word “wheat” being present.

Soy sauce — Most standard soy sauces — including varieties sold as “light soy sauce” or “dark soy sauce” — are brewed by fermenting a mixture of soybeans and roasted wheat. The wheat is a fermentation substrate, not a flavour note, so it is easy to miss when reading a recipe.

Seitan — Made by washing wheat flour dough to remove starch, leaving behind concentrated wheat gluten. It is the wheat-derived meat alternative used in many plant-based recipes and is sometimes listed under the Japanese name fu.

Fu (Japanese dried wheat gluten) — A traditional Japanese ingredient made from dried wheat gluten, used in soups, simmered dishes (nimono), and some religious vegetarian cooking. It appears under the name fu, usually preceded by a space, which is how Frittu's keyword list catches it without false-matching words that end in “fu”.

Atta and maida — Two wheat flours common in South Asian cooking. Atta is a whole-wheat flour used for rotis, parathas, and chapati. Maida is a fine refined wheat flour used in naan, some pastries, and fried coatings. Both appear by name in recipe ingredient lists and are in Frittu's keyword list.

Spelt, kamut, einkorn, emmer — Ancient wheat relatives that contain gluten. They are sometimes presented as “heritage grains” or described as more digestible than modern wheat, but they are wheat and they contain gluten.

Farro and freekeh — Farro is a collective name applied to emmer, spelt, or einkorn — all wheat. Freekeh is roasted green wheat common in Middle Eastern and Mediterranean cooking. Both commonly appear in grain bowls and salads.

Semolina and durum — Semolina is the coarsely milled endosperm of durum wheat, used in most dried pasta, couscous, and some pizza dough. Durum appears as an ingredient name in some specialty pasta recipes. Both are flagged by Frittu's keyword list.

Bulgur and couscous — Bulgur is parboiled and dried cracked wheat, common in Middle Eastern cooking. Couscous is made from semolina — despite being shelved near rice or lentils in many supermarkets, it is a pasta product. Both are flagged.

Panko and breadcrumbs — Panko is a Japanese-style breadcrumb made from crustless wheat bread. Standard breadcrumbs are also wheat-based. Both are caught by Frittu's keywords (panko and crumb).

Barley and rye — Both are gluten-containing grains used in baking and as whole grains. Barley also appears in malt vinegar and in the description of some beer-based marinades. Both are in Frittu's wheat keyword list.

Triticale — A hybrid of wheat and rye developed in the 20th century. It appears occasionally in specialty grain products and health-food recipes.

Graham flour and wheat starch / wheat germ — Graham flour is a coarsely ground whole-wheat flour used in crackers and some baked goods. Wheat starch and wheat germ are wheat-derived ingredients sold in health and specialty food stores — all three are flagged by Frittu's keyword list.

Ingredient names with shared terms. Some ingredient names contain wheat-associated terms but refer to non-wheat products — for example, “rice noodles,” “corn tortilla,” and “chickpea pasta.” Frittu's post-generation check distinguishes these from their wheat-based equivalents by examining the ingredient name as a whole. A plain “noodle” or “pasta” without a qualifying prefix is flagged.

Frequently asked questions

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

Frittu uses a two-layer process. First, before generating a recipe, Claude is given an exclusion list covering wheat and its common aliases — including fermented products that contain wheat (such as soy sauce), ancient wheat varieties (spelt, farro, and others), regional wheat flours (atta, maida), and wheat-derived meat alternatives (seitan). 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 wheat. Any match causes the recipe to be rejected and Frittu attempts to generate an alternative.

Does Frittu's check allow rice noodles in a recipe where wheat is excluded?

Yes. The check recognises that some ingredient names share terms with wheat-based products without actually containing wheat — for example, "rice noodles" and "corn tortillas." Frittu's post-generation check examines the ingredient name as a whole to distinguish these from their wheat-based equivalents. A plain "noodle" or "egg noodle" without a qualifying prefix would be flagged and the recipe rejected.

Why does Frittu check soy sauce when excluding wheat?

Most commercially available soy sauces are brewed using a mixture of soybeans and wheat. The wheat serves as a fermentation substrate — it is not a prominent taste or visible ingredient, which is why it is easy to overlook in a recipe. Frittu's wheat keyword list includes "soy sauce" directly, so any recipe that calls for soy sauce is flagged and regenerated when wheat is excluded from a user's profile.

What happens when a generated recipe triggers the wheat 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.

Does the check cover gluten introduced during kitchen preparation?

No. The check operates on ingredient names as listed in the generated recipe. It does not cover shared equipment, oils used for cooking wheat-containing foods, or ingredients a user adds after receiving the recipe. Standard kitchen precautions — dedicated equipment, careful cross-contamination controls — remain relevant regardless of what a recipe generator produces.

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