directly to the consumer, explain these natural phenomena to the customer who then serve the wine gently in order to prevent the crystals forming in the bottom of the bottle. The presence of unstable proteins that can create a visual problem (protein breakdown) in the wine also requires stabilization. Treatment with bentonite allows the precipitation of unstable proteins which can then be removed by filtration and extraction. The proteins can also react with Metatartaric acid added to wine to prevent tartaric precipitation: the wine then loses its shine and becomes opalescent like whey. Some varieties are naturally high in protein (muscat. ..) but levels also vary depending on the vintage and maturity levels. Finally some white wines can be victims of Rosissement (pinking). This phenomenon manifests itself in a light rosé colouration of the wine and takes the appearance of a "stained" wine or one that is contaminated by the presence of anthocyanins from red wine. Yet this is not so: the phenomenon is due to the presence of a normally colourless dissolved polyphenol which turns pink due to oxidation. An infusion of PVPP generally eliminates the substrate of oxidation. Some varieties are particularly sensitive to pinking: Sauvignon B, Viognier, Grenache B... Use of SO2 SO2, sulphur dioxide or dioxide of sulphur is used in all winemaking operations from harvesting to packaging. It plays a protective role in the wine against the phenomena of oxidation, oxidase enzyme action (enzymes that oxidize the polyphenols in wine), and the control of microbial populations in yeasts and bacteria (antiseptic effect). The maximum allowable doses depend on the sugar content of the wine: the residual sugar is susceptible to attack by microorganisms which would cause a restart of fermentation. In France the dose is limited to 150 mg/litre for Vin de Pays (country wines), 185 mg/L for Sparkling wines, 200 mg/L for Fortified wines, 200 mg/L for dry white wines, 250 mg/L for white wines with residual sugar greater than 5 g/litre (Moelleux wines), and 300 mg/L for liquoreux sweet wines. Filtration and conditioning For sale to individuals or restaurants the wine is filtered if necessary, then conditioned. The filtration consists of passing the wine through a filter element for retaining fine particles suspended in the wine. It may be fine earth (Kieselguhr), cardboard sheets, membranes, or Cross-flow filtration. Packaging wine has historically varied. In one early method, wine merchants kept their stock in