Is modified food starch gluten-free?

This one has a satisfying answer, because the labelling rules let you infer something rather than leaving you guessing.

The inference

Modified food starch can be made from corn, potato, tapioca or wheat. In the US it is most often corn.

Wheat is one of the nine major US allergens. If the starch were made from wheat, allergen labelling would require the source to be declared. So a US label that says only “modified food starch”, with no mention of wheat anywhere on the package, is not a wheat starch.

That is a real, enforceable inference rather than an optimistic reading.

In the EU and UK, cereals containing gluten must be named and emphasised within the ingredient list, which gets you to the same place by a different route.

Two caveats worth keeping

Labelling conventions differ elsewhere. The inference above is about the market you are shopping in, not a universal property of the ingredient.

A claim beats an inference. If the product also carries a gluten-free claim, the under-20-ppm threshold applies to the finished food regardless of what the starch was made from. For coeliac disease that is a materially stronger assurance than an ingredient list with nothing obvious in it.

The other worry, while we are here

“Modified” does not mean genetically modified. It means the starch has been physically or chemically treated so it thickens properly, resists heat and survives freezing. It is a process applied to an extracted starch, not a change to a plant’s DNA. The two words are unrelated and the label is using the technical one.

The full page is Modified food starch, and the ingredient that actually catches people out in this category is Barley malt extract, because barley carries no allergen warning at all. Both sit on the gluten-free page.