Method for cleaning a solid support of a fermentation reactor comprising a contaminated polyurethane foam

A process for cleaning a solid support of a fermentation reactor for the production of alcohols by fermentation of a sugary fluid, the solid support comprising a polyurethane foam inoculated with a bacterial biomass produced by a solvent-producing strain belonging to the genus Clostridium, the process comprising placing the solid support in contact with a fluid originating from the fermentation must containing alcohol and/or a fluid originating from the fermentation must containing acetone the fluid originating from the fermentation must eliminates 97-99% by weight of the bacterial biomass immobilized in the polyurethane foam relative to the total weight of the bacterial biomass.