A filtration column is shown below. It is employed to remove the yeast still suspended in the beer. High pressures can destroy the filtration column. High filter pressures can be caused by a cake of filtered yeast on the trays not allowing the beer to pass. This column uses diatomaceous earth to keep the filter pressure low.
Diatomaceous earth is an algae that has a hollow structure similar to a skeleton.
Before the beer is entered into the column, it is mixed with the earth. As the mixture is filter, the yeast and the earth both are collected. However, the hollow bodies of the diatomaceous earth allow the beer to continue past the cake. Uncovered Filtration Column Exposing Trays Storage tanks are illustrated below. This is where further aging of the beer can be performed or just simple storage until ingestion.