The flours, and what actually separates them

PROTEIN decides how much gluten can form. High-protein flours build a strong elastic network that holds gas — bread wants that. Low-protein flours build little, so the crumb stays tender and is held by set egg and gelatinised starch instead — cakes want that. Almost every name on a British shelf is a position on this scale: cake flour lowest, plain in the middle, strong or bread flour highest.\n\nEXTRACTION decides how much of the grain is left. White flour is endosperm only. Wholemeal contains the bran and germ too, which brings flavour and nutrition and cuts the gluten network as it forms — which is why a wholemeal loaf is denser than its protein content suggests.\n\nEverything else is a modifier: self-raising is plain flour with baking powder in it, 00 is a fineness of milling rather than a protein grade, and rye is a different grain that behaves by different rules entirely.

BREAD, PIZZA, BAGELS: strong or bread flour. The chew is a developed gluten network and there is no substitute for the protein to build it from.\n\nCAKES AND DELICATE SPONGES: cake flour where you can get it, plain flour with some replaced by cornflour where you cannot. Gluten here is the enemy.\n\nMOST EVERYDAY BAKING: plain flour. It is a compromise by design and a good one — pastry, biscuits, sauces, ordinary cakes.\n\nSCONES AND QUICK BAKES: self-raising, with the caveat that its raising agent ages in the bag.\n\nPASTRY: plain flour, and lower protein is better. A strong flour makes a tough shortcrust.\n\nWholemeal and rye are not substitutions for these; they are different ingredients with their own behaviour, and blending them with white flour is standard rather than a compromise.

British plain flour and American all-purpose flour occupy the same slot and are not identical: American all-purpose is typically a little higher in protein, and American cake flour is usually chlorinated in a way British soft flour is not.\n\nItalian 00 confuses people because it is a MILLING grade rather than a protein grade — it describes how finely the flour is ground, and 00 flours exist across a wide protein range. Buying 00 for pizza and getting a soft one is a common and invisible disappointment.\n\nThe practical response is to read the protein figure on the packet where one is given, because it says what the name only implies.