Pizza flour: the complete guide to W index, protein and hydration, 102 flours compared

The short answer

The W measures the energy needed to inflate a bubble of dough until it bursts, on the Chopin alveograph. It is the strength of the flour: its ability to hold gas for a long time. For a same-day direct pizza, 200 to 260 is enough; for 24 to 48 hours in the fridge, 280 to 320; beyond 48 hours, with a biga or above 75 % water, 320 to 400. The P/L says whether the flour is tenacious (it springs back in the hands, P/L above 0.7) or extensible (it stretches, P/L around 0.5). Protein, for its part, predicts neither from one flour to the next: Caputo's durum semolina shows 13 % and a W of 230, the Pizzeria 12.5 % and a W of 260 to 280.

In Canada, no mill we checked publishes a W. Five Roses and Robin Hood give 4 g of protein per 30 g serving, which, because of rounding, means anything between 11.7 and 15 %. La Milanaise publishes percentages with a ±1 % tolerance, Les Moulins de Soulanges and Ardent Mills warn that protein varies with the crop. That is why the Canadian flours in the Fornello library are rated C, and why the tables below say "not published" rather than a number.

Reading a technical sheet

Two pieces of mill honesty deserve quoting. Petra (Molino Quaglia) declines to give a W for its high-fibre stone-ground flours, "because the high fibre content does not allow significant results on the Chopin alveograph". And Dallagiovanna calls the W values of its Uniqua range "indicative". When a mill says what it does not know, it is a good sign for the rest of its sheet.

Which W for which schedule

The Dallagiovanna mill publishes the most direct equivalence between strength and time, for one line of flours: W 200 for 3 hours at room temperature or 8 hours in the fridge, W 250 for 6 to 7 hours or 12 hours, W 290 for 10 hours or 24 hours, W 340 for 12 hours or 48 hours, W 390 for 16 hours or 72 hours. Molino Pasini says the same thing in days of walk-in cooler: 10 hours for a W 200–220, 20 hours for 240–270, one to two days for 280–310, one to three days for 380–400, two to six days for 390–420. Petra adds hydration: 50 to 60 % water for its 5046 (W 180–220), 55 to 70 % for the 5063 (W 260–280), 65 to 85 % for the 5037 (W 300–340).

A synthesis of the recommendations published by Dallagiovanna, Molino Pasini, Petra, Caputo and Molino Vigevano (sources below). The hours are the mills', at an Italian kitchen temperature; Fornello recomputes them at yours.

The calculator below opens at the intermediate level: pick a flour from the library, or blend two, and watch the blend's W, its P/L, and the maturation ceiling the engine derives from them. It is the simplest way to build a W 280 from a Canadian bread flour and an all-purpose, knowing the result is at confidence C.

Italian flours, mill by mill

Values copied as is from the mills' product pages on 6 November 2026. A range (260–280) is the mill's range, not ours. "Not published" means the mill's page does not give the value. Uses and schedules are those the mill recommends, summarised.

Caputo now calls "Saccorosso" the flour long sold as Cuoco (red bag) or Chef. Two internal inconsistencies at Caputo, flagged rather than corrected: the English category page lists the Nuvola at W 260–280 while its product page says 270–290, and the 1 kg Tipo 1 shows 14 % protein in its spec box and 13 % in its text. Polselli publishes its W with a tolerance (+0 to 5 %) and gives 270 for professionals, 280 for retail, for the same Classica.

North American flours: plenty of protein, almost no W

Only Central Milling publishes a W, for its 00 flours. King Arthur, General Mills, Rogers and Ardent Mills publish protein percentages (and often ash); Five Roses, Robin Hood and Bob's Red Mill give only the nutrition label, in grams per serving. Every Canadian value in this table is therefore to be validated on the mill's sheet, and taken as an order of magnitude. Note the additives too: Canadian supermarket bread flours often contain ascorbic acid, amylases, sometimes xylanase and L-cysteine, which change the dough's behaviour without touching the protein percentage.

A Canadian label "4 g per 30 g" covers, because of rounding to the gram, 11.7 to 15 % protein: it cannot tell an all-purpose from a bread flour. Ardent Mills' ranges (11.4 to 12.4 %) and La Milanaise's tolerance (±1 %) are the honest form of the same information.

How much water for which flour

A pizza's hydration is chosen first by style and oven, then corrected by flour. Two markers from the mills themselves: Petra gives a water range for each flour (50 to 60 % for a W 180–220, 55 to 70 % for a W 260–280, 65 to 85 % for a W 300–340), and the farinographs published by Le 5 Stagioni, Soulanges and Rogers give the absorption at standard consistency (55 to 66 %). Three rules follow. A stronger flour drinks more water and holds it longer. A stone-ground or whole-grain flour keeps drinking for 30 to 60 minutes after mixing, hence autolyse and bassinage. And a flour whose protein is boosted with vital gluten (like Central Milling's Tony Gemignani) drinks a lot without giving the extensibility of a flour that is strong by nature.

The reading traps

1. Comparing a Caputo W to a Le 5 Stagioni "energy". They are not the same instruments. Compare flours from one mill with each other, then use the recommended schedule as the bridge.
2. Reading 14 % protein as "strong". Vigevano's Vesuvio shows 14.5 % and a W of 270 to 290; Caputo's Pizzeria 12.5 % and 260 to 280. Same strength, two percent apart.
3. Taking a 00 for a strong flour. "00" is an extraction rate (little ash), not a strength. There are 00s at W 200 and 00s at W 400.
4. Taking a Canadian bag at its word. 4 g per 30 g is all the label guarantees. For a pizzeria, ask the distributor for the technical sheet: Ardent Mills and Rogers publish them.
5. Forgetting the lot. The published W is a target; the year's crop moves it by ten points and more. The bake journal exists to measure your own flour.