wine and sometimes to correct faults such as excess tannin. Fining agents include egg white and gelatin. Some red wines, particularly those designed for early drinking, are cold stabilized so as to prevent the precipitation of unsightly tartrate crystals in the bottle. Filtration and bottling Most wines are filtered at some stage before bottling, although some winemakers use the absence of filtration as a marketing tool. Filtration serves to make wine completely clear and to eliminate any remaining yeast cells and bacteria, which could render the bottled wine microbiologically unstable. Wine is normally filled to glass bottles with cork stoppers, though aluminium screwcap closures and plastic stoppers are also common. Alternative containers such as Bag-in-Box, TetraPak and plastic bottles are also used. See also Browning in red wine Health effects of wine Storage of wine References Shades of red