Abstract: A method for removing organic contaminants including yeast cells from a particulate filter aid such as kieselguhr includes steps of producing an aqueous suspension of the contaminated filter aid, and adding to the suspension a mixture of enzymes (protease, amylase and glucanase) capable of dissolving yeast cell walls. Optionally, an oxidizer may also be added, and the suspension may be agitated ultrasonically. After sufficient time, the enzyme and dissolved organic contaminant are removed from the suspension by rinsing with dilute caustic soda, and the decontaminated filter aid is acid neutralized. Finally, the filter aid may be separated into coarse and fine fractions, and re-used.