The fine wines of the Langhe > Modern techniques and equipements

The grapes must arrive at the cellar in their best conditions. It has to be avoided the squashing, maceration, juice airing and the following oxidation phenomena or partial fermentation. In order to do this: containers for the harvesting and transport, which are 20-60 cm profound; only one container for the transport from the vineyard to the cellar; cleaning of the containers; protection of the grapes from the rain and dust; manufacturing of the grapes as fast as possible (from the basket to the pannier, then to the trailer, and finally to the unloading ditch; or from palletized boxes to dumper chart or trailer, liftable or not, auto-emptying. The grapes arrived at the cellar; they are weighted, sampled, selected and pressed or their stalks removed. Stalk-removers can be horizontal or vertical centrifuge, according to the position of their main organs (the drum and the beater): the quality of the work performed by a stalk-remover is evaluated according to: the quantity of grape stalk fragments which are in the must, the integrity of grape stalks which have been ejected by the machine, the elimination of vine-branches, leaves or external elements. The best removal of grape stalks avoids the laceration of the grape and allows the discharge of juice by pressing. Must is extracted from fresh grapes, and wine from fermented grapes, by press, which is often employed to separate the first fractions from the last, since the first part, which is 60-80%, is obtained by draining. Presses can be vertical or horizontal, hydraulic, mechanic, or pneumatic-energised; the pressing organ can be a “plate”, an air chamber or an “Archimedes’ screw”; it can work discontinuously and cyclically or continuously; the classification consists of: vertical presses, hydraulic horizontal or mechanic or pneumatic presses, continuous presses and dynamic drainers. Presses are evaluated according to the duration of the operations, the power and capacity. In the cellar there are cisterns, which are grounded recipients with one or two superior openings; the barrels are made of wood, the “semprepieno” is the recipient which can remain partially empty by floating covers or inert gas heads. The clarifying tanks must be not very high and rather thermally isolated, in order to avoid the deposit of sediments. The materials: wood, reinforced concrete, common and stainless steel, plastic materials such as resins. For the choice, the economical aspects, the total and unitary capacity, shapes, dimensions and the emptying easiness, are evaluated. For vinification tanks could be chosen stainless steel ones and, if possible, they could be put outside, with a suitable thermal control. For red wines there are major opportunities for the choice, according to the options of maceration, warm or cold, long or short fermentation. In small firms, re-assembling and eliminating the marc are manual operations and flat bottoms, low doors and/or rotating auto-emptying tanks; so for the medium or big size vats:  manual-emptying with inclined bottom, also stainless, or progressive controllable emptying; although, it is always important to evaluate carefully advantages and disadvantages of the choice. The bottling and tapping phase has reached unthinkable standards nowadays: bottlers can be manually alimented (semi-automatic) or automatic, with a conveyer belt. The filling techniques can be: volumetric, which supplies a determined volume, with a disparity of 0,2-0,5%, and possible irregular capacity of the bottles, and different levels; constant level, where bottles are filled at the same level and the volume of the liquid introduced depends on the recipient capacity. These are the most utilized fillers in enology, both for normal and sparkling wines. They are divided into: siphoned, isobaric, and differential pressured. The siphoned ones work according to the principle of the communicating vases and have several disadvantages; in the isobaric ones, the wine contained in the alimentation tank has the same pressure of the wine entering the bottle; the differential pressured ones (vacuum-sealed) produce a high depression: there is a perfect seal between the neck of the bottle and the alimentation tap, and a careful maintenance is necessary. During the filling, oxygen may enter and melt, causing damages: it is possible to limit this dissolution by utilizing inert gas, after the filling and before the corking; carbon dioxide can increase or decrease according to bottling techniques: it decreases if the bottling temperature is high; it increases with a carbon dioxide “counter-pressure” system.