Pizza Flour Types Explained: 00, 0, 405 and 550

"Use 00 flour" is probably the most repeated piece of pizza advice on the internet, and also one of the most misunderstood. The double zero tells you something real, just not the thing most people think. Once you know what flour grades measure, and what they leave out, picking a good pizza flour gets much easier, wherever you shop.

What the grade actually measures

Both the Italian and the German system are built on ash content. A flour sample is burned at around 900 °C, and what remains is mineral ash. Because minerals are concentrated in the outer layers of the grain, the ash shows how much of the bran ended up in the flour: little ash means a white, finely extracted flour; more ash means a darker flour with more of the outer layers.

What ash does not measure is how much protein the flour has, or how good that protein is. And that is exactly what decides whether a dough survives a 24-hour rise.

Italian grades: tipo 00 to integrale

In Italy, soft wheat flour (grano tenero) is regulated by Presidential Decree no. 187 of 9 February 2001. For each grade it sets a maximum ash content and a minimum protein content, both on a dry matter basis, plus a maximum moisture of 14.50 %.

Two things stand out. First, protein only has a floor. A 00 with 9 % protein is just as legal as one with 13 %, but they make very different doughs. Second, grades 00 to 2 have no minimum ash, only a maximum. So "00" really tells you the flour is very white, not that it was made for pizza.

Durum wheat is regulated separately in Italy and sold as semola. It plays no role in a Neapolitan dough itself, but it is popular for dusting the peel.

German grades: 405, 550, 812, 1050, 1600

If you shop in Germany, or in a German supermarket chain abroad, you will see type numbers instead. Under the German standard DIN 10355, the number states the average mineral content in milligrams per 100 g of dry matter. Type 405 means roughly 405 mg of ash per 100 g of dry flour.

Unlike the Italian law, the German type number sets no protein requirement at all. Two type 550 flours from different mills can behave quite differently in a dough. Wholemeal flour carries no type number because it contains the whole grain.

Comparing the two systems

There is no exact conversion because the limits are drawn differently, but the ash values give a rough map:

In practice, a German 550 is about as white as an Italian tipo 0 and usually a closer match to Italian pizza flours than 405. Whether it actually works for your dough, though, comes down to protein.

Why protein and gluten matter more

When you knead, the proteins gliadin and glutenin form gluten. Gluten traps the gas from fermentation and gives dough its stretch. More and better protein generally means a dough that absorbs more water, ferments longer and opens without tearing.

Quantity is not the whole story. Two flours with the same protein figure can behave differently, because gluten quality depends on wheat variety and growing conditions. That is why mills also test baking performance with instruments such as the alveograph.

The W value and P/L

How the alveograph works

The Chopin alveograph turns flour and salted water into a thin sheet of dough and inflates it like a balloon until it bursts, mimicking how gas bubbles grow in fermenting dough. The machine records the pressure inside the bubble as it expands. Three figures come out of the curve:

• P (tenacity): the maximum pressure the dough resists with. A high P means a tough, resistant dough.
• L (extensibility): how far the bubble stretches before it tears.
• W (deformation energy): the area under the curve, the energy needed to inflate the bubble. It is reported in units of 10⁻⁴ joules, which is why typical values have three digits.

What W and P/L tell you

W is the most widely used indicator of flour strength. A high W usually means strong gluten that can handle long fermentation and more water. The P/L ratio describes balance: high P/L means a firm, less extensible dough, low P/L a soft, very extensible one. For pizza you want a dough that stretches thin without tearing or springing back.

The AVPN gives these values for flour suited to long rising times:

A fair caveat: the alveograph is an empirical test. Research shows that W is closely tied to gluten strength and to the flour's water absorption, while bran and damaged starch raise water absorption and mainly push up P. Numbers from different mills are therefore only roughly comparable.

Which flour for which fermentation?

The rule of thumb: the longer the fermentation, the stronger the flour should be. There are no official cut-offs, so read this table as orientation.

Read more about fridge schedules in cold fermentation and about water in hydration explained.

Manitoba: the heavyweight

In Italy, "Manitoba" is printed on flours that are especially strong. The name points to the Canadian province whose hard spring wheat is known for high protein. According to the Canadian Grain Commission, Canada Western Red Spring wheat exported in 2023/24 had a grain protein content of roughly 13.4 to 14.2 % and very strong dough properties. Manitoba is not a legal grade, though: such a flour is classified under one of the normal Italian grades, usually 0 or 00, and the name alone does not guarantee Canadian wheat.

Used on its own, Manitoba is too strong for most pizza doughs, which turn tough and shrink back. As part of a blend or in long preferments it can be very useful.

Practical buying tips

• Read the nutrition panel: protein is the one figure every bag states reliably. For 24 hours or more, lean towards a higher-protein flour.
• Use W and P/L when you can get them: if the bag or the mill's data sheet lists them, take advantage. If not, that is not a bad sign, just less information.
• Stick with one flour: switching constantly makes results impossible to compare. Bake a few batches with one flour and adjust water and yeast.
• Store it well: dry, cool and sealed.
• Look past the label: "pizza flour" on a bag is not a standardised claim about strength. Protein and, where available, W tell you more.

Tarte flambée follows slightly different rules because the dough should be thin and firm; see our tarte flambée dough guide. And for how flour, water, salt and yeast come together, head to the perfect pizza dough.