What flour actually is
All flour is milled grain – most commonly wheat – but the variety of wheat, the part of the grain used, and how finely it is milled all shape what a flour can and cannot do. The key variable in wheat flour is protein content. More protein means more potential gluten, and gluten is what gives bread its chew and structure. Less protein produces a more tender, shorter crumb – exactly what you want in a biscuit or shortcrust pastry.
That single principle – protein level shapes texture – makes most flour choices straightforward.
The everyday three
Plain flour is the workhorse. Milled from lower-protein wheat, it suits pastry, sauces, batters and biscuits. No raising agent is built in, so you control what lift, if any, you add.
Self-raising flour is plain flour with baking powder already measured in, designed to take one variable out of home baking. It works reliably for sponges, scones and many traybakes. The catch: the raising agent loses potency over time, so an old bag can leave a cake disappointingly flat. If yours has been in the cupboard a while, replace it.
No self-raising flour to hand? Combine plain flour with baking powder. The widely used ratio is two level teaspoons of baking powder per 150g of plain flour – a culinary convention rather than a fixed rule, and some recipes benefit from a small adjustment either way.
Strong flour – sold as bread flour – is milled from higher-protein wheat. Given water, time and yeast or a starter, that extra protein develops into the elastic gluten network that lets a dough trap gas and rise. Use it for yeasted breads, enriched doughs such as brioche, and pizza bases. Plain flour in a bread recipe is not a disaster, but the loaf will be denser and less chewy.
When '00' comes into play
'00' flour is an Italian classification of fineness rather than protein content alone – the name refers to how finely the grain is milled, producing a silky powder with relatively low protein. It rolls out into a smooth, supple sheet for fresh pasta and gives a thin, slightly crisp pizza base. For a British kitchen it is a specialist buy, but if you make pasta or Neapolitan-style pizza regularly, the texture difference over plain flour is noticeable.
Wholemeal, brown and spelt
Wholemeal flour uses the whole grain – bran, germ and endosperm – which explains both its deeper flavour and its denser results. Bran physically interrupts gluten development, so a 100% wholemeal loaf is heavier and shorter than a white one. Many bakers blend the two, using wholemeal for flavour while keeping enough white flour for a lighter crumb.
Brown flour sits between the two: some bran has been removed, so it bakes lighter than wholemeal but has more character than white.
Spelt is an ancient relative of modern wheat with a slightly nutty flavour. It contains gluten, but the gluten it forms is more fragile and extensible than that of common wheat. Spelt doughs need a gentler hand and shorter kneading times – overwork them and the structure collapses rather than strengthens.
Stoneground and heritage grains
The revival of stoneground milling and heritage wheat varieties has brought genuinely different flours back onto the market. Stoneground flour is milled between slow-moving stones rather than steel rollers; the process generates less heat, which many millers argue preserves more of the grain's natural oils and flavour.
Heritage varieties such as Einkorn, Emmer and older British wheats behave quite differently from modern milling wheats. Their protein structure, hydration needs and baking behaviour often require adjustment when following a recipe written for a supermarket flour. We cover this in more depth in a companion piece on heritage grains and stoneground milling – worth reading before you bake with them for the first time.
Storing flour well
White flours keep well in a cool, dry cupboard away from strong-smelling foods. Wholemeal and spelt are different: the natural oils in the bran and germ can turn rancid, so they are better used within a few months of milling. If you buy in bulk or live somewhere warm, the fridge or freezer extends their life considerably. Check the best-before date on any flour before baking – it matters more than most people assume.
