The milling process: from wheat to flour

Once harvested, the wheat is transported to silos where it's dried and stored for several months. It is then taken to the mills by truck, train, or canal boat, where it is stored in silos again.

Traditionally, wheat was milled in small mills that worked thanks to wind or water power. Many of these mills are  now functioning again, but most flour is now made in industrial mills.

Industrial mills began to appear in the 19th century. At the time, the mills in these large buildings were powered by water. Today, they are equipped with electrical motors and work automatically, sometimes 24 hours a day. Bakers buy their flour from there.

Wheat is transported around the mills via bucket elevator or suction tube to undergo different cleaning operations.

The wheat is cleaned and sorted so that only the healthy grain is kept, and impurities are removed (like dust, small stones, hay, or poor-quality grain). Different machines are used for this purpose (like sieves, croppers, peelers, sifters, suction tubes, brushes)

Healthy grain needs to be kept at optimal humidity levels so it can be milled. This makes it easier to separate the kernel from its casing. They are therefore humidified or dried before being left for 24 to 48 hours in bushels for clean wheat storage.

After it's cleaned and humidified, the grain is turned to flour in three steps:
- grinding
- reducing
- sifting

The wheat grain is passed through machines with large cylinders to separate the grain from its casing.

This process repeats around five or six times between cylinders that are closer and closer together with  thinner flutes each time.

This operation consists of grinding the grain even more finely to obtain a powder

This is the final step to get a finer powder that will become flour. The product passes through various fine cylinders to get a very fine flour. Some modern industrial mills have added several pairs of milling machines to their factory floors.

Sieving is done in plansifters. These are wooden crates containing horizontal sieves that are powered by an external force attached by a belt. They separate out the product of the milling process. The plansifter room is especially noisy.

The flour is stored in a flour chamber and put into sacks. The sacks are labeled with the name of the miller and the mill.

The sacks are still sealed by hand in certain industrial mills.

Flour in France is labeled with a T then a number. The letter T stands for Type. The whiter the flour, the lower the number. The most refined flour is all-purpose flour. It is one of the most widely used in pastry-making and is labeled T45 in France. It is made up entirely of the kernel of the wheat grain.