biological stability in champagne wines. For a sweet wine, fermentation is stopped before its end to keep some of the sugar: this is the Mutage (fortification). The fermentation can be stopped by adding Sulphur Dioxide (SO2) (sterilisation of wine), by sudden cooling (anaesthesia of yeasts), by sterile filtration (capturing the yeasts in a very fine mesh filter), or a combination of several of these methods. A rule of thumb for determining the point of mutage, which allows a good balance of acquired alcohol and residual sugar, is to leave as many potential degrees as the degrees acquired over 10% by volume. For sweeter dessert wines fermentation stops spontaneously by excess sugar and alcohol: Alcohol is waste from the yeast and it is poisonous in large doses. In the case of sweet wines an addition of wine alcohol stops the fermentation. FML is not done for sweet wines as the lactic bacteria preferentially degrades sugar which would give a lactic bite (sweet and sour wine). In addition, the balance of acidity and sugar in the wine supports vivacity. A winemaking technique called "reducing" or "technology" has been developed. Very fashionable in Australia and New Zealand, this technique seeks highly aromatic white wines and is very interesting on aromatic varieties such as Sauvignon B, Colombard B, and Riesling B, although less so for varieties such as Chardonnay B. It works by limiting Premature oxidation in the must or the wine at all stages of development. The use of inert gases such as Carbon Dioxide (CO2) isolates the grapes from oxygen from the air and cold partially inhibits the action of oxidative enzymes in the must. Tyrosinase, a natural enzyme in the grape, and laccase, an enzyme coming from the gray mold are very active in oxidation. Laccase can be eliminated by sorting the grapes. Strong limitation on the amount of polyphenols in the wine by reducing the time between harvest and pressing is another technique that aims to make a very light wine, protected from yellowing. Preparation of wine before packaging After fermentation all wine requires constant care to be fit for consumption. All of these practices before bottling are known as élevage or Maturing. Maturing Maturing can be done in a vat. It takes little time to clarify and to prepare the packaging (bottling or Bag-In-Box) but this may be extended by maturing of lees. This type of maturing consists of