First take a handful of flour, hold it tightly in your hand, and then open your hand. The flour will soon return to its original state. The raw materials of this kind of high flour are durum wheat, and its flour grains are slightly thicker than those of low flour, so it looks gritty.

On the contrary, after opening your hand, the cake flour will feel a little slippery, and the flour will remain on the fingertips, forming lumps. The raw material of this cake flour is soft wheat, and the powder grains are relatively fine.

Initially, the composition of starch and protein in the endosperm of hard wheat and soft wheat was different. Because soft wheat is relatively fragile, it is very easy to form fine flour.