Ash Content of American and European Flour Types

Knowing the ash (mineral) content of your flour is essential to optimizing bread baking processes, especially on a commercial or industrial level. Why is it so essential, you ask? Because ash content affects fermentation activity, dough strength, nutrition, colour, and flavour of final bread products.

In brief, understanding the effects of ash content may help you troubleshoot or minimize bread-related problems, whether baking casually at home or professionally in a bakery.

Woman mixing sticky dough by hand

“This dough is too sticky! If only I knew the ash content of the flour beforehand…”


Crunched down to the basics, ash content is determined by:

1. Placing a sample of flour in a cup (called an ash muffle);
2. Incinerating the sample at above 500°C / 932°F in a laboratory ash oven;
3. Cooling the residue (ash) to room temperature;
4. Weighing the residue;
5. Expressing the weight of the residue as a percentage.

The residue is composed of noncombustible, non-organic minerals, derived mostly from the bran or outer layer of the grain kernel (seed). Depending on the variety of the grain, soil conditions, climate, and other factors, ash content will vary from flour to flour—even from the same brand.

Woman holding wheat stalks in her hands and a diagram of a grain kernel

Wheat stalks to the left; diagram of a grain kernel to the right


In the USA and United Kingdom, flours are labeled with generic names such as “bread flour” and correspond to a quantified range of protein content. In comparison, some European nations label their flours according to standardized regulations regarding ash content. For example, in France, wheat flours range from Type 45 (pastry flour) to Type 140 (whole wheat flour).

Prepared by yours truly, you may visit this link to download a chart (in Microsoft Excel format) comparing the ash content of various flours. The chart lists common types of wheat flour from the USA, United Kingdom, and a few nation members of the European Union.

Further, when viewing the chart, please keep in mind that ash content is expressed in percentages in relation to the flour’s original weight. To exemplify, if 100 grams of flour yields 2 grams of ash, the ash content of that flour is “2.0” percent.

Screenshot of a Microsoft Excel sheet containing a chart comparing the ash content of various flours

Ash content comparison chart


Minerals act as a buffering agent, allowing bacteria to produce more acids before the acidity level of the dough is high enough to hinder their growth. In other words, greater ash content may result in greater perception of sourness in your bread.

Greater ash content may also speed up fermentation activity, improve dough strength (around 0.5 ash content enables balanced properties of strength), and enhance the nutrition, colour, and flavour of bread products. However, in excess, ash content may weaken dough and reduce its gas retention.


1: Ash Content. The Artisan.
2: Determination of Ash in Biomass. National Renewable Energy Laboratory. [PDF]
3: Flour Types. Wessex Mill.
4: Lactic Acid Fermentation in Sourdough. The Fresh Loaf.
5: Section 3: Wheat and Milling Tests. Wheat and Flour Testing Methods. [PDF]
6: The Strength of the Dough: Part I. The Bread Club.
7: Understanding Ash Count. Progressive Baker.
8: Wheat Flour Standards in European Union. The European Flour Millers. [PDF]

Author: Zita (bakingbadly)
Published: September 11th, 2013

One Response to “Ash Content of American and European Flour Types”

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