Tuesday, March 12, 2013

Wine process - Part II

We continue with the wine process and as we told you in our last post, with the FERMENTATION, one of the most important points during the elaboration process.

The grape juice needs to overcome two different fermentations, the alcoholic and the malolactic.

The alcoholic fermentation is the process when the sugar turns into alcohol.
That is with are needed the yeasts, microorganism that we can find naturally in the grape skin (kind of white dust you can find out side the grape skin).

The oxigen is the responsable to start this fermentation, because of the yeasts need it in their growth period.
However, at the end of the fermentation the quantity of oxigen must be smaller to keep the ethyl alcohol and get the acetic acid. 

From the alcoholic fermentation, we obtain heat energy and we have to control the temperature because if it increase too much,(25-30 ºC) the yeasts could die and the fermentation will be stooped.

Another product from the alcoholic fermentation is the gas, carbon dioxide and it cause the bubbles and the boiling effect, and of course the characteristic aroma from the fermentation. There is a video from our tanks during this period, it is amazing! More than 30.000 litres... 

This boiling effect makes the grape skins go to the top of the tank (solids) and create the "hat". This "hat" protect the grape juice from bacteria and another microorganism from the skin and also is from we get the tanins and the color, aromas and  another susbtances like Resveratrol located in the skin.