Interactive lesson

Milling flour, step by step

Interactive lesson: from clean, dry grain to flour in the bag — preparing the grain, choosing a mill, milling, sifting, maize and storage.

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The whole lesson as text

1. Grain and flour

A wheat grain has three parts, and they decide what kind of flour you get.

Three parts of the grain — The white part (endosperm) gives starch and gluten. Bran gives fibre and minerals. The germ gives oil and vitamin E, but also quick rancidity.
Wholemeal and white — Wholemeal flour (whole wheat in North America) contains the whole grain, with bran and germ. White flour is only the white part: it keeps a long time, but it is poorer.
What T550 means — Continental Europe labels flour by the ash left when it is burned. Type 550 (Balkan T-500) has about 0.5% ash, Type 1100 about 1.1%. A higher number means more bran. UK and US mills name flour white, brown or wholemeal instead.
Store grain, mill fresh — Grain at 13% moisture in a cool store lasts two to three years. Wholemeal flour lasts 1–3 months, so mill 2–4 weeks ahead.

Why: When you mill your own, you know the field, the variety, the moisture and the day it was milled. Grain keeps for years in a dry store, flour only for a few months. If you keep grain and mill as you need it, you hold a reserve that doesn't go off.

From 100 kg of wheat you get roughly 90–95 kg of wholemeal or 70–75 kg of white flour; the rest is bran.
With a home mill and a sieve you realistically get wholemeal and light brown flour. True white flour (pastry flour, strong white) needs the roller mills of a real mill.

2. Preparing the grain

A mill doesn't fix bad grain: whatever goes into the mill ends up in the flour.

Check a handful — Grain must be winnowed and sieved. Before milling, spread a handful on a light-coloured surface once more and look.
Take out the dangerous — Sieve out stones. Pick out every ergot, a dark purple horn 1–3 cm long. Corncockle is a black, rough seed: sieve and pick over.
Moisture 13–14% — Damper grain glues the stones, and the flour clumps and spoils fast. Below 11% the bran shatters and is harder to sift out.
Damp it lightly — If you will sift, add 10–20 mL of water per 1 kg of grain 8–12 hours before milling and stir in a lidded bucket. Don't go above 15% moisture.

Why: A stone damages the millstones, and ergot and corncockle are poisonous. Mould toxins and ergot alkaloids are not destroyed by milling, cooking or baking.

Don't mill mouldy grain, or grain with a lot of ergot or bunt, for food or for animals.
If you suspect poisoning (cramps, tingling fingers, nausea), see a doctor and take a sample of the flour; if it is severe, call 999/112 (UK, IE) or 911 (US, CA).