Is flour ultra-processed?

Wholemeal flour is group 1: milled wheat, nothing added, nothing removed beyond what milling does.

White flour is where it gets genuinely difficult, and the reason is the law rather than the manufacturer.

UK flour is fortified by statute

The Bread and Flour Regulations require that flour sold in the UK, other than wholemeal, has calcium, iron, thiamin and niacin added to it. This is not a choice a mill makes and it is not printed as a marketing claim. It has been the law since the 1940s and it exists for public health reasons.

Fortification is a group 4 marker under NOVA. Added vitamins and minerals are substances added to a formulation rather than something present in a food, which is why most breakfast cereal is group 4 even where the rest of the list is short.

Applied strictly, that puts a bag of plain white flour in the same group as a fizzy drink. Almost nobody would defend that as a useful statement about the two products.

What to make of it

In practice most published work treats statutory fortification of a staple differently from a manufacturer choosing to add vitamins to a product, and classifies plain flour as group 1. That is a defensible reading and it is not what the definition says on its face. It is the clearest example on this site of the reproducibility problem set out in the criticisms.

The parts that are not ambiguous

• Wholemeal flour: group 1, and legally exempt from fortification.
• Self-raising flour: group 3, since the raising agent is added.
• Bread mixes and cake mixes: group 4, from the emulsifiers and improvers.
• Gluten-free flour blends: usually group 4, being built from starches and gums.

It is also worth knowing when reading a loaf. Most sliced bread is group 4 on its emulsifiers regardless of this argument, so the flour question rarely changes the answer for a finished product.

Working this out from a receipt is harder than from a packet, because a till prints about twenty characters of product name and no ingredients list. That is the problem Bagged exists to solve, and how a receipt is structured explains why it is the hard part.