Protein content – why 12.5% isn’t the same as strong flour
Protein content and W value measure different things, and usually only one of them is printed on the bag. How to use the protein figure without being misled.
Quick answer: Protein content (grams of protein per 100 g of flour) is the only strength-related figure on most supermarket flour bags. It correlates loosely with how much gluten the flour can build, but it does not measure the same thing as the W value – two flours with the same protein content can behave completely differently in a dough.
Why the numbers aren’t interchangeable
The W value measures the dough’s actual mechanical strength in an alveograph: how much work it takes before the bubble of dough bursts. Protein content only measures the amount of protein, not its quality or how well it forms gluten when hydrated (see the gluten guide). A flour with high protein content but ”broken” protein (damaged by poor storage or milling, for example) can still give a weak dough.
How to use the number anyway
As a rule of thumb: protein content below 11 % suits short, same-day fermentation, 11–13 % works for up to a day of cold fermentation, and above 13 % (often imported 00 flour) is needed for 48–72 hours. It is a rough approximation, not a guarantee.
For the bigger picture, see which flour suits which oven and what the tipo 00 label does and doesn’t tell you.
