Which process removes yeast cells and other microorganisms by pumping through cellulose pads or diatomaceous earth?

• A. Filtration
• B. Fining
• C. Maceration
• D. Press

Answer: (A)

Filtration removes yeast cells and other microorganisms by forcing the wine through a filter medium, such as cellulose pads or diatomaceous earth. The liquid passes through the porous material and particles larger than the filter’s pore size are trapped, yielding clearer wine and reducing microbial load. This is a physical separation, distinct from fining, which uses additives to bind particles so they settle or are removed. It’s also different from maceration, which is about extracting color, flavor, and tannins from grape skins during fermentation, and from pressing, which is about physically extracting juice from grapes. Filtration provides clarification and microbiological stabilization by removing suspended organisms as the liquid passes through the filter.