There are different types of flour such as all-purpose flour and 00. The properties of flour are determined by the protein content and the size of the particles.
Lots of Parameters
There are many parameters that can be used to classify wheat flour. Two of the most commonly used are ash value and protein content. It is very difficult to consider all the other factors such as wheat variety, place of origin, milling method and particle size.
Therefore, we will focus on the two parameters that have the greatest impact on cooking, protein content and grain size, and examine flour in more depth.
Ash Value? Why Ignore?
Ash value is related to minerals. The lower the minerals, the whiter the color of the flour will be. In the flour world, ash value is expressed as a grade. The lower the ash content, the better grade flour(*1).
The ash value affects mainly color, taste and protein content. The inner part of the wheat grain is whiter and has less protein. So, in general, flour made from the outer part of the wheat grain will have more ash value, more color, and more protein. Flour made from the inner part of the wheat has less ash value, is whiter, and has less protein.
As you can see, a single ash value can contain a lot of information. In this article, we will leave the ash value, which contains multiple elements, aside to consider each parameter.
Type of Wheat is Important
The type of wheat also plays a major role in the properties of flour. You may have heard of hard wheat, soft wheat, durum wheat, and so on.
Let’s try to compare hard wheat and soft wheat. Hard wheat contains more protein. And because it is harder, the particles are coarser. In other words, when we think in terms of the type of wheat, as well as the ash value, there is a lot of information included.
In order to make things simpler and more logical, we will focus on the protein content and grain size instead of the ash content and type of wheat.
Protein Content of Flour
In Japan, wheat flour is classified by the amount of protein.
Protein content(%) | Classification |
---|---|
11.5-12.5 | Strong flour |
9-11.5 | Semi-strong flour |
8-9 | Midium flour, Plain flour |
6.5-8 | Light flour |

Flour Particle Size
In Finland, flour is classified by the size of the grain.





Impact on Cooking
How does the protein content and particle size of flour affect cooking?



Flour in Japan, Finland, America and Europe



References
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