Grape must

The grape must is the product of mechanical operations on the grapes obtained from the harvest, and consists of pulp, peel and seeds of grapes, and grape must for vinification is made from the pulp alone.

Squeezing the grapes, grapes are treaded and stalks separated (with stemming).

There are several methods of processing of grape must in the case of white grapes, red grapes with white or red wine.

In the case of preparation of  red grape must , white vinified – for example - the crushing of the grapes will be so mild and gentle, so as not to include in the liquid color elements present in the grape peels.

It is important in the production of the grape to control the values ​​of sugars and acids present.

Typical values ​​of the acid component, generated by bacteria and yeast, for the grape must , have a pH around 4.3, depending on the climate in the year, on soil type and geographic location.

At this acidity, in composing the taste notes of grape must, oppose the sugar component given by the sugars fructose, glucose and small parts of sucrose which is transformed at the beginning of the machining process of the grape must.

In grape must, composed mostly by water in a percentage of about 80%, there are also a wide variety of substances including vitamins, mineral salts and nitrogenous substances necessary to yeasts.

The grape must to become wine needs bacteria that ferment the juice, transforming the simple sugars glucose and fructose into ethyl alcohol, and developing heat.