FR2658837A1 - Process for making mellow and dry white wines by fermentation in the presence of grapes (vat fermentation) - Google Patents

Abstract

Production of smooth and fruity white wines, pleasant in the mouth, by a wine-making process in three successive phases: First phase called vat fermentation. Fermentation phase in the presence of grapes during which the must will acquire all its qualities. Second phase called separation phase. Upon draining, separation of the non-expressed juice and the expressed juice under the protection of the carbon dioxide produced by the fermentation with lowering of the temperature. Third phase called processing phase. End of fermentation phase at low temperature, during which phase the conventional treatments used in traditional wine making can be applied. Production of a smooth and very fruity non-expressed wine and of a more neutral but richer expressed wine which, after treatment, can most often be reintegrated.

Description

VINIFICATION PROCESS IN DRY AND SWEET WHITE WINES
BY FERMENTATION IN THE PRESENCE OF GRAPES (BAKING) - == ooOoo = -
The present invention relates to a winemaking process from white grapes for obtaining a white wine with highly developed organoleptic characters.

Changes in consumer tastes encourage consumers to look for supple and fruity white wines that are very pleasant on the palate. Achieving it by the traditional method is often difficult
Direct pressing before fermentation or even simple pre-fermentation maceration gives only random results and over the years is unreliable. The extracted aromas are often weak and their protection during fermentation requires the most severe temperature monitoring and constant attention to oxidation. It is therefore desirable to have a process which will make it possible to extract the maximum of perfume while safeguarding the taste qualities of the finished product whether it is dry white wine or sweet white wine. This is the aim of the present invention. In order to ensure the best results, the grapes must be picked ripe and in perfect sanitary condition. It is not possible to use the present invention in the event of heavy rot.

 This winemaking process will implement three successive phases. To do this, whether by manual or mechanical harvest, the grapes will be destemmed and the harvest cleaned before placing in the tank.

 In the first so-called vatting phase, the grapes will be crushed when the tank is loaded. A slight sulphiting (4 to 5 g / hl of pure SO2) will make it possible to clean up the environment while promoting maceration. Treatment with pectolytic enzymes at a dose of 1 to 2 g / hl will ensure better exchanges by degradation of "protective colloids" (pectins and other colloidal substances). Yeasting with activators will accelerate the start of fermentation. This yeasting will be carried out at an average dose of 10 g / hl and will mostly use saccharomyces cerevisiae or other breeds under certain conditions.

 During this first phase, from the start of fermentation, the pumping over of the must will be carried out partly in the air. Their purpose is to homogenize and aerate the environment in order to facilitate the exchange of seed juice which is very important for the quality of the finished product.

 The duration of vatting will be determined by the temperature and the speed with which the seed will degrade to release the maximum of flavors while avoiding an excess of tannins. We know that the transformation of sugar into alcohol, result of the work of microorganisms that are yeasts, produces heat and a strong release of carbon dioxide and this according to an increasing curve. Examples of winemaking have shown that a temperature of 25 centigrade represents a limit beyond which the degradation of the aromas was faster than their extraction; It is also from this temperature that the increase in tannins and in particular the most aggressive tannins begins to be felt in the juice. This temperature of 25 centigrade is therefore retained as the maximum limit temperature. In cold years, other examples of winemaking have shown that the degradation of the seed is much slower. The temperature limit is no longer a determining factor. However, it is imperative to protect the must during the second phase with the carbon dioxide produced by fermentation. The fixed limit is no longer a temperature limit but a density limit: Weight of a liter of must in fermentation; density expressed in grams and 200 which is measured using a special aerometer called a mustimeter. This limit is around 1025 at the end of the full fermentation period linked to the maximum production of carbon dioxide.

 The duration of vatting thus determined by the two factors temperature limit and density limit, can therefore range from a few 72 hours to ten days depending on the conditions of the year.

 At the end of this first phase we obtain a must of great richness and very good gustatory quality which we will have to keep until the end of vinification.

 The second phase, known as the separation phase, will allow the separation of the drop juice and the press juice. The release of carbon dioxide will protect the future wine when it is poured. The juice of drop which represents 60 to 70% of the total volume will be quickly drained in a fresh tank and its temperature brought back to 180 maximum this by avoiding any aeration. The press richer in tannins and whose oxidation during pressing is inevitable, will be collected in a second tank and kept at the same temperature of 180 maximum.

 The third phase, known as the production phase, will allow all or part of the remaining sugar to be transformed into alcohol. It operates on two different products: gout juice and press juice. In both cases, the fermentation will be carried out in parallel and in a similar way.

 In the case of dry white wines, the alcoholic degree may if necessary be corrected by enrichment according to standards and legal products; this as soon as it flows. This enrichment will be accompanied by yeasting at 10 g / hl of Bayanus saccharomyces. The musts are then treated with bentonite at 60 - 80 g / hl to limit oxidation. Throughout this third phase, the temperature will be controlled and maintained between 16 and 180 centigrade. Measures may possibly be taken to promote malolactic fermentation: deacidification, bacterial seeding. This secondary fermentation which transforms malic acid into lactic acid is not often taken into account in traditional white wine making. The bacteria that carry out this biological transformation are difficult to control, and she certainly has an interest in this new vinification process which seeks a better balance in the wine. When the fermentable sugars have disappeared, racking will take place immediately followed by sulphiting around 10 g / hl of pure sulfur dioxide. If the malolactic fermentation is in progress, we can try to delay this sulphiting in order to complete it.

In the current state of our cellar equipment, it is often very risky to extend this wait beyond 48 hours because of oxidation.

 In the case of sweet white wines, the musts are treated with bentonite at 60 - 80 g / hl and the temperature maintained at 16,180 as in the previous case. The malolactic fermentation can be favored under the same conditions. When the desired alcohol-sugar balance is approached, the degree may be corrected by legal enrichment. Temperatures can be lowered gradually by about ten degrees to slow fermentation, reduce the activity of yeasts and their resistance to sulphiting. This sulphiting will be carried out once equilibrium has been reached and after drawing off at the average dose of 20 g / hl of pure sulfur dioxide.

 In all cases, the press wines obtained and vinified separately will be fined and filtered in order to remove the excess hardness of the tannins. After tasting, they can most often be re-incorporated into gouty wines.

The characteristics of the white wines thus produced are such that they correspond to those of the appellation claimed so much: - in terms of color
- highly developed fruity aroma
- suppleness and balance on the palate.

Claims (2)

1 - Vinification process in dry and sweet white wines by fermentation in the presence of the grape (vatting) characterized in that it comprises three distinct and successive phases  - The first so-called vatting phase of 72 hours or more. Duration limited on the one hand by the temperature which must remain below 250 centigrade and the density of the must, measured with the mustimeter, expression of the richness in sugar which at schooling must be greater than or equal to 1025.  It is the phase of fermentation of the crushed and sulphited grape in the presence of microorganisms such as saccharomyces cerevisiae and pectolytic enzymes. Phase during which the must will enrich with the elements contained in the seed, in particular the aromas.  - The second so-called separation phase occurs at the time of the flow, the drop juice and the press juice are separated in two different tanks whose temperature is brought to 180 maximum very quickly; this phase is done under protection of the carbon dioxide produced by fermentation and protected from air as much as possible.  - The third so-called development phase. The musts obtained are vinified at 16 - 180 and undergo the treatments usually carried out in traditional vinification: bentonite and, if necessary, yeasting; correction of degree, acidity. 2 - Product obtained according to the process according to claim 1 characterized in that it consists of 60 to 70% by volume of supple and fruity drop wine and respectively from 40 to 30% of more neutral but richer press wine which can, after treatment, be used as a cut and most often be reintegrated.