Sulfites or sulfur dioxide is naturally found in wine at low levels, but then typically add more for better conservation of the wine. This practice has been done for centuries and is intended to preserve the wine, it inhibits bacteria and mold, prevents oxidation of the wine, preserving the aroma and freshness. According to winegrowers, without this additive could not guarantee the quality of the wine.
It is obligatory to put on the label of the bottle of wine when you are in concentrations of more than 10mg / liter, because as indicates the European Directive 2003/89 / EC, indicate any ingredient with allergenic capacity and in the case of the sulfites.
An excess of sulfites in wine quality also worsens, loses color, taking a pungent smell and taste alters, therefore can be trusted not to administer more than necessary, because the wine lose quality. For the amount to be applied first will measure sulfur that naturally already in the wine.