also known as leaching. There are two types of diffusers. One relies on immerging the mat of bagasse in the juice by counterflow. The other relies on percolation of the juice through the mat of bagasse.

At a chemical level, the first step is to open the cells. This is usually done by revolving cane-knives and a three roller crusher, which together open most of the thin-walled cells. The juice is then removed from these opened cells by leaching. I.e. the sucrose from these opened cells