In the first place let's clarify that is difficult to express how to elaborate wine in a few words, we just try to convey to the reader what we can summarize after visiting wineries, especially in times of harvest and what the experts explain about.
If we simplify, we can say that what is needed for the grape juice to transform into wine is a process that should be the most natural way possible: fermentation. This is a chemical phenomenon whereby the grape sugar turns into alcohol and carbon dioxide, and it is produced by the intervention of the yeasts found in greater proportion in the skins. When the grape skins are broken, yeast start to work on sugar resulting in fermentation.
Then the grapes are brought from the vineyard holding together the bunches, then settled to the wine press, a cellar space for that function, next they will pass through the destemming process, there emerge the grains to be pressed and the juice extracted. This juice, consisting of pulp, skins and seeds is called must, and this will be put to ferment in tanks or barrels. Normally yeast would act to transform all the sugar into alcohol, or at least until it reaches a level of 15% alcohol in wine, but often happens that some grapes are too sweet and the process must be stopped manually.
Currently the process by which wines are elaborated is accompanied by the use of technologies never even imagined for such process, elements that are now extremely needed to ensure quality. For example, it is known that white wines require that fermentation occurs at low temperatures, thereby cooling equipment will be necessary to slow down the fermentation process, achieving control of the process and preventing the oxidation, an absolutely damaging agent in the process of creating wine. By contrast, red wines do not require temperatures as low, but the oxygenation should be also avoided in its elaboration process.
Those wines which mature in oak casks, whether white or red, face a very soft oxygenation process because the element is ?strained? in small proportions, but stops if it is bottled and corked. Its stay in bottle is necessary and essential to make the wine settle, achieving an optimal point of maturity.