Filtration is a process that occurs during clarification, right before bottling. It involves passing the wine through a filtration medium to separate any particles from the liquid in order to remove the opaqueness of the wine and create a clear and stable final product.

The filters remove any sediments such as dead yeast cells and bits of grapes left from the winemaking process. There's also a process called fining where you add something that binds to the sediment, typically a type of protein such as egg whites.