What is the difference between the flours?

The flour shelf looks like a dozen unrelated products. One number — protein content, printed on every bag — explains most of the difference between them.

Step by step

1. Read the protein figure.On the nutrition panel, per 100g. Higher protein means more gluten, which means more structure and chew. That single number predicts behaviour better than the name on the front.
2. Use strong flour for bread.12 to 14% protein. It develops the gluten network that traps gas and gives a chewy, open crumb. Bread made with plain flour is dense and flat.
3. Use plain flour for most other things.9 to 11%. Cakes, sauces, pastry, batters, thickening. Lower protein means a tenderer result, which is what you want in a cake.
4. Understand self-raising.Plain flour with baking powder already in it, roughly two teaspoons per 150g. You can make it yourself, and it loses potency over months, which is why old self-raising gives flat cakes.
5. Know when 00 matters.Italian 00 refers to how finely it is milled, not to protein. It comes in different protein levels — a strong 00 for pizza, a softer one for pasta. Fineness gives a silkier texture.
6. Treat wholemeal as different, not just browner.It contains the bran and germ, which cut the gluten strands and absorb more water. Wholemeal bread needs more liquid and rises less. Substituting it one for one gives a brick.
7. Substitute wholemeal partially.Start at 25 to 30% wholemeal with the rest white, and add a little extra liquid. That gives most of the flavour without losing the rise.
8. Use soft or sponge flour for delicate cakes.Around 7 to 9% protein. It produces a finer, more tender crumb. Plain flour works perfectly well; this is a refinement rather than a requirement.
9. Know what happens if you swap strong for plain.In a cake, tougher and chewier. In pastry, shrunken and hard. Neither is a disaster but both are noticeably worse, and the reverse gives dense bread.
10. Handle gluten-free flour as a different ingredient.Blends have no gluten to build structure, so they need a binder such as xanthan gum and behave differently. Use recipes written for them rather than substituting.
11. Store it properly.Airtight, cool and dark. Wholemeal contains the oily germ and goes rancid within a few months — keep it in the fridge or freezer if you use it slowly.
12. Check the date on raising agents.Self-raising flour and baking powder both lose strength. If cakes have stopped rising and the method has not changed, that is the first thing to check.

Tips

• Read the protein per 100g. It tells you more than the name on the bag.
• Old self-raising flour is the commonest cause of a cake that stopped rising for no apparent reason.
• Keep wholemeal in the fridge. The germ contains oil and it goes rancid within months.

Common mistakes

• Swapping wholemeal for white one for one — The bran cuts gluten strands and absorbs more water, so the loaf is dense and dry. Start at 25 to 30% and add extra liquid.
• Using strong flour for cakes and pastry — The extra gluten makes cakes chewy and pastry tough and shrunken. Plain flour is lower protein for exactly that reason.

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