The key to understanding French flour is the concept of “ash content” or taux de cendres.

The Science Behind the ’T’ Ash Content.

In simple terms, the “T” number is determined by burning a sample of the flour and weighing the mineral-rich ash that remains. This ash primarily comes from the bran (the outer shell of the wheat kernel). Therefore:

A low T number (T45) means: The flour is highly refined, with very little bran left. It has a low ash content (around 0.45%), is very white, and produces a fine, light texture.

A high T number (T150) means: The flour is much less refined, retaining most of the bran and germ. It has a high ash content (around 1.5%), is darker in color, and has a more robust, nutty, and rustic flavor.

Think of it as a scale of refinement and flavor intensity, from the most delicate pastry flour to the heartiest whole grain flour.

A Guide to French Flour Types and Their Uses.

Flour Type: T45. Fleur de Farine.
Ash Content: 0.4% – 0.5%.
Best Uses: Pastries & Fine Baking: Croissants, brioche, puff pastry, financiers, cakes, crêpes.
Characteristic: Very white, fine, and light. Provides a tender crumb and its mild flavor allows other ingredients (like butter) to shine.

Flour Type T55. Classic White Flour.
Ash Content: 0.5% – 0.6%.
Best Uses: Versatile All-Purpose: The classic French flour for standard baguettes, white bread, pizza dough, and also pies and choux pastry.
Characteristic: The go-to flour for everyday baking. It offers a good balance of structure and a neutral flavor.

Flour Type T65. Baker’s Flour.
Ash Content: 0.62% – 0.75%.
Best Uses: Artisan Breads: The flour of choice for “Tradition” baguettes, sourdough, and other rustic breads requiring long fermentation.
Characteristic: Has a creamy color and a more pronounced wheat flavor.

Flour Type T80. Farine Bise (Brown Flour)
Ash Content: 0.75% – 0.9%.
Best Uses: Semi-Wholemeal Breads: Often used for heartier country breads, often mixed with T65 for a lighter texture.
Characteristic: A semi-wholemeal flour that adds a nutty flavor and more fiber.

Flour Type T110. Wholemeal Flour.
Ash Content: 1.0% – 1.2%.
Best Uses: Wholemeal Bread: For making “pain complet”. It can be dense, so it’s sometimes blended with white flour to improve development.
Characteristic: A true whole-wheat flour with a high fiber content, robust flavor, and darker color.

Flour Type T150/170. Whole-grain Bread.
Best Uses: For the densest, most rustic “pain intégral” with a very high bran content like the dark rye sourdough.
Characteristic: Contains the entire wheat kernel. It is very high in fiber and has an intense, earthy, and slightly bitter flavor.

A Note on “Farine de Tradition”.

You may also encounter the term “Farine de Tradition” on a bag of T55 or T65. This is a special classification in France. Unlike standard flours, which may have additives like ascorbic acid or malted barley flour to strengthen the dough, “Tradition” flour is guaranteed to be without additives. It is the gold standard for creating authentic, flavorful French bread with a protected designation.

Traditional French bread flour is specially formulated for crafting authentic French breads using time-honored methods. It contains no added gluten or enhancers such as ascorbic acid. A traditional T55 or T65 flour produces a creamy crumb with beautiful air pockets and a golden, crispy crust—the ideal characteristics of a classic French baguette. This flour typically has a protein content of approximately 10%, a gluten level of 6–7%, and a W value of 200.

The Equivalents: Italian vs. French Flour.

Both systems are ways to classify flour, but they achieve this using slightly different philosophies. The key is that Italian flours are graded by how finely ground they are, while French flours are graded by their mineral (ash) content. However, a very practical and widely-used equivalence exists between them.

In Italy, flour is classified by how much of the wheat grain’s outer layer (the bran) has been sifted out during milling. This is often referred to as the “extraction rate.” The lower the number, the more refined and whiter the flour.

Important Nuances: Protein and Strength.
While this comparison is a helpful guide, it’s crucial to remember that the “type” of flour doesn’t tell the whole story. A flour’s strength and protein content can vary significantly within a single type, which greatly affects its performance.

For example, Tipo 00 flour from Italy is famous for making Neapolitan pizza. This is because high-quality 00 flours often have a very high protein content (around 12.5–13.5%) and a high “W” index (a measure of flour strength), allowing the dough to be stretched thin and develop large, airy bubbles during a long fermentation. A Tipo 00 with a W of ≈380 is advised for the Panettone recipes for instance.

A French T45 flour, by contrast, typically has a lower protein content and is designed for flaky pastries like croissants, not chewy pizza crust.

Similarly, a strong Tipo 0 flour (sometimes labeled as “Manitoba”) can be excellent for long-fermentation breads and pizza, outperforming a weaker T55 in structure-building ability.

In short: the Italian and French systems can be mapped to each other, but for the best baking results, it is always a good idea to check the protein content and specific ‘W’ recommendations on the package for your intended recipe.

Final Thoughts For Home Bakers.

When making sponges, cookies, batters, cakes, and pastries at home, the flours required for these recipes are usually easy to find in supermarkets around the world. However, when it comes to making bread, it’s a different story. You can find decent bread flour brands that offer good compromises, but for the best results—and for other key ingredients like meat, eggs, vegetables, cheeses, and even wine—the ultimate choice is to source them directly from the producer.

Even in France, when I want to make bread, I don’t buy flour at the grocery store. Instead, I go straight to a local flour mill (minoterie). If that’s not an option for you, try to find a reputable bakery where you can purchase good-quality bread flour for your homemade recipes. Ultimately, if none of these options are available, choose a good unbleached all-purpose flour that is low in protein, ideally around 8 percent.