Fermentation is the process in which yeasts transform sugar into alcohol and carbon dioxide.
In the case of young white wines, once the must has settled it is transferred to a stainless steel tank where fermentation will take place, either using the natural indigenous yeasts or by adding selected yeasts.During this process, which gives off bubbles of CO2, the temperature of the must rises and gives the impression the must is boiling.
This heat must be drawn off, because if the must warms up too much during fermentation, the process accelerates and the fruit aromas can be lost to evaporation. Moreover the wine could develop undesirable tastes. For this reason fermenting tanks have refrigeration circuits on the outside, know as “shirts”. Cold water is pumped through these circuits to keep the temperature of the must below 16-18ºC.
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