CH666886A5 - PROCESS FOR TREATING CORK STOPPERS. - Google Patents

Description

DESCRIPTION

The present invention relates to a method for treating cork stoppers as well as an installation for its implementation and the use of stoppers treated by this method for corking a bottle filled with drink and, more particularly, for corking. a bottle of wine.

The use of cork stoppers for corking wine bottles has been essential from time immemorial, because it has been found to have irreplaceable advantages over any other method of corking. In particular, cork stoppers have the essential advantage of allowing the passage of a certain amount of air which provides the amount of oxygen necessary for good aging of the bottled wine after vinification.

However, the inventory of qualities of cork stoppers, as they are currently used, has certain shortcomings, which are essentially the following:

- classic cork taste, detectable by smell or taste;

■ - various false tastes coming directly from the cork;

- drips that stain the cork and cause excessive air entry into the bottle, which can cause stinging of the wine;

- excessive porosity of the cork resulting in the stinging of the wine, especially when the storage temperature of the bottles is high;

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- decomposition of the cork by the cirons which were in the original cork;

- defects inherent in the natural botanical origin of cork.

The treatment methods used, up to

Now, in order to eliminate some of the defects listed above, in particular those which are due to the natural origin of cork, have not provided a satisfactory solution. In fact, these processes are themselves responsible for the production of substances which give false tastes to wine. In particular, research carried out at the Federal Research Station for Arboriculture, Viticulture and Horticulture in Wädenswil has revealed the presence, in wines with a "corky taste", of 2,4,6-trichloroanisole as well as 2 , 3,4,6-tetrachloroanisole and pentachloroanisole. These compounds, the first of which is responsible for the taste of the cork itself and the other two would also give rise to false undesirable tastes, would be formed, as a result of the interaction between chlorine and chlorides with cork lignin, in the presence of moisture and micro-organisms found in cork in their natural state, during the usual treatments for bleaching chlorine stoppers and for washing them with chloride solutions.

It should also be noted that, even in the absence of chlorine or chloride, the presence in the plugs of moisture which results from the treatment of the cork sheets by immersion in water, with a view to softening them and to give them the consistency necessary for their de-biting and for turning the plugs, as well as for the wetting operation, or steaming, of the plugs to give them the flexibility and compressibility desired during their use for capping bottles during bottling, leads in the long run, within the cork, to a stagnation of water in the presence of micro-organisms coming from cork itself as well as dust suspended in the air, which it results, in any case, the formation of substances capable of imparting an unpleasant taste to the wine.

This state of affairs is all the more regrettable as the progress of winemaking has made it possible to improve the wine by increasing its bouquet.

The invention therefore aims to eliminate the aforementioned defects, through a treatment of the plugs having the effect of making them absolutely neutral from the chemical and biological point of view, without any deterioration of their intrinsic qualities.

To this end, the method of treating stoppers according to the invention has the characteristics specified in claim 1.

Advantageously, the plugs are dehydrated and at least partially sterilized by subjecting them to heating under reduced pressure. For example, this operation can be carried out by maintaining the plugs, for at least 90 minutes, at a temperature between 120 and 150 ° C., under a pressure between 0.01 and 0.05 • 105 Pa.

In accordance with a particularly advantageous embodiment of the method, the stoppers are subjected, immediately after the dehydration and sterilization operation by heating under reduced pressure, and before their impregnation with the impregnation material, to a sterilization operation at heart consisting in maintaining them under an inert gas atmosphere, anhydrous, under a pressure higher than atmospheric pressure, at a temperature and for a period of time sufficient to allow such sterilization. As inert gas, to carry out sterilization at the heart of the caps, carbon dioxide is preferably used. One can, for example, carry out sterilization at the heart of the caps by maintaining them for at least 30 minutes, at a temperature between 120 and 150 ° C., in the atmosphere of carbon dioxide, under a pressure at least equal to 4 • 105 Pa.

As impregnation material, it is advantageous to use beeswax or a homogeneous mixture of beeswax and at least one inert substance. More particularly, a mixture of 60 to 90 parts by weight of unrefined beeswax and 10 to 40 parts by weight of paraffin is preferably used as the impregnation material. Preferably, a mixture of unrefined beeswax and purified paraffin is used, consisting of 75 parts of wax and 25 parts of paraffin. It should be noted that the use of natural, unrefined beeswax, which contains natural antibiotics, makes it possible to give the stopper immunological autonomy against cryptogamic or microbial attacks.

In accordance with a particularly advantageous mode of implementation of the method, the plugs are impregnated by immersion in a bath of beeswax and paraffin mixture maintained in the liquid state, at a temperature of 70 to 75 °. C. Advantageously, after sterilization at the heart of the plugs in the atmosphere of inert gas under pressure and immediately before their immersion in the bath of beeswax and paraffin mixture, the pressure of the inert gas atmosphere is reduced at a value of between 0.01 and 0.05 Pa and the plugs are left to cool to a temperature between 50 and 80 ° C. and the plugs are then immersed in the bath, by introducing the mixture of wax and paraffin, in the liquid state in the enclosure containing the atmosphere of inert gas under reduced pressure;

Advantageously, after the plugs have been impregnated, the excess impregnation material covering the external surface of the plugs is eliminated. For example, this operation of removing excess impregnation material can be carried out by wringing.

The installation according to the invention, for implementing the process which has just been specified, is characterized in that it comprises a sealed treatment enclosure, provided with heating means as well as means for establishing therein, at will and alternately, an industrial vacuum and an atmosphere of inert gas under pressure; a removable basket, suitable for receiving a batch of plugs to be treated, this basket being arranged so that it can be, at will, 'placed inside the treatment enclosure and withdrawn therefrom with its load of plugs ; a tank of impregnation material,

provided with heating means making it possible to carry and maintain • this material in the liquid state; and means for supplying the treatment enclosure with liquid impregnation material from this reservoir, and for returning this material to this reservoir from the treatment enclosure.

Advantageously, the installation further comprises a centrifugal wringer arranged so as to be able to receive said removable basket, as a wringing drum, this wringer being provided with heating means and means for collecting the impregnation material from the separate plugs. of these by spinning. According to a particularly advantageous embodiment of the installation, the means for establishing the vacuum and the pressure in the enclosure comprise a suction and pressure pump which also serves to circulate the liquid impregnation material between the reservoir of this material and the processing enclosure.

The use of the stopper treated by the process specified above for the stopper of a bottle filled with a beverage is characterized in that, before the establishment of the stopper in the neck of the bottle, the stopper is kept at a temperature and for a sufficient time to soften the impregnation material, so as to give the plug an appropriate flexibility for its positioning in the neck. Preferably, in the case where the impregnation material consists of a mixture of beeswax and paraffin, the temperature at which the stopper is maintained, in order to soften it before its use, is between 50 and 55 ° C and the duration of keeping the stopper at this temperature is approximately 60 minutes. However, depending on the composition and the concentration of the impregnation mixture used for the treatment of the plugs, the cold use, that is to say at room temperature, without any prior heating operation, of the plugs which have undergone processing according to the invention is also perfectly possible.

In the case of a bottling of wine shortly after vinification, it is advantageous to inject a stream of oxygen onto the free surface of the wine, after filling the bottle and immediately before placing the stopper in the neck, so

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that the volume comprised between this surface and the stopper contains from 0.03 to 3 cm3 of oxygen per liter of wine. Oxygen is thus fixed in the wine, in the form of microbubbles, which accelerates its aging and allows the development of its bouquet. Due to the fact that the stopper treated by the process according to the invention places the wine protected from any penetration of outside air, the quantity of oxygen thus introduced into the wine can be perfectly defined, which allows adjustment the evolution of the redox potential of the wine and, consequently, to regulate at will the evolution of the bouquet thanks to the optimization of the redox potential.

The invention will be better understood, thanks to the detailed description which follows, of a nonlimiting example of implementation of the method, with reference to the appended drawing, in which:

Figure 1 is a schematic view, in elevation and in partial section, of a part of an installation for the implementation of the method, in accordance with a particular embodiment;

FIG. 2 is a schematic view, also in elevation and in partial section, of another installation part which can advantageously be added to that which is shown in FIG. 1.

The part of the installation shown in FIG. 1 comprises an autoclave 1, constituting a stopper treatment chamber, arranged so as to allow the maintenance of an industrial vacuum (pressure reduced to a value between 0.01 and 0, 05 • 105 Pa, for example of the order of 0.015 to 0.017 • 105 Pa) or else of an inert gas atmosphere, such as carbon dioxide, under a pressure which can reach a value of the order of 6 to 7 • IO5 Pa. The autoclave 1 is provided with heating means making it possible to reach and maintain any temperature between ambient temperature and 150 ° C. inside the treatment enclosure.

The caps to be treated are placed inside the autoclave 1, in a removable perforated basket 2, made of stainless steel sheet, which also constitutes the spinning drum of the centrifuge shown in FIG. 2.

The autoclave 1 is connected, by a conduit 3, to an electric suction and discharge pump 4 which makes it possible to establish in the enclosure of the autoclave both the industrial vacuum and the compression.

In addition, the autoclave 1 is connected on the one hand, by a conduit 5, to a reservoir of impregnation materials 6 and, on the other hand, by a conduit 7, to a commercial carbon dioxide bottle 8.

The reservoir 6 is itself connected to the pump 4 by a conduit 9 on which a valve 10 is inserted.

Valves 11 and 12 are also interposed, respectively, on line 3 and on line 5.

The implementation of the method according to the invention in the installation illustrated in Figure 1 is carried out as follows.

After placing, inside the autoclave 1, the basket 2 containing the raw cork stoppers to be treated, having undergone no prior treatment after cutting them out of the cork sheets and therefore being in their natural state , the autoclave is closed, a vacuum of 0.015 to 0.017 • 105 Pa is established by means of pump 4, and it is heated to a temperature between 120 and 150 ° C., for at least 90 minutes while removing the water vapor released by the plugs, as it is produced. This produces practically complete dehydration and sterilization of the caps. After which, without opening the autoclave, the enclosure of the autoclave is filled with carbon dioxide gas from bottle 8, under a pressure of 6 to 7 • 105 Pa and the temperature is maintained between 130 and 150 ° C. , for 30 minutes, which ensures complete sterilization at the heart of the caps.

The carbon dioxide is then removed, by means of pump 4, until the pressure drops to a value of 0.015 to 0.017 • 105 Pa and the temperature of the plugs is allowed to drop to a temperature of 80 ° C. about. Then a homogeneous mixture consisting of 75% by weight of beige, unrefined beeswax, and 25% by weight of pure, refined, white paraffin is introduced into the autoclave enclosure, this mixture being liquid state at a temperature of 75 ° C and coming from the reservoir 6 through the conduit 5, so as to constitute a bath of impregnation material. The plugs are kept immersed in this bath, at 75 ° C., for 5 minutes. After which, the bath of impregnation material is evacuated from the autoclave and it is returned to the tank 6 by the conduit 3 and the conduit 9, by means of the pump 4.

Immediately after the plugs have been impregnated, and while the temperature is still between 70 and 75 ° C., the basket 2 containing the plugs impregnated with a mixture of beeswax and paraffin is quickly transferred into a centrifugal wringer (shown in Figure 2) whose basket 2 constitutes the spinning drum. Then the plugs are wrung out, while maintaining them at a temperature of 70 to 75 ° C, by rotating the drum for the necessary time and with the appropriate speed (for example for 5 minutes, with a rotation speed corresponding to a linear speed 20 meters per second) to remove excess impregnation material covering the outer surface of the plugs and give them a satin appearance corresponding to the desired commercial finish. Corks of excellent appearance are thus obtained, having no tendency to form a deposit of materials for impregnating the plug on the glass.

As can be seen in FIG. 2, the centrifugal wringer 13 is driven by an electric motor 14 allowing rotation speeds of the drum corresponding to a linear speed range from 10 to 30 meters per second. After opening the removable cover 15 of the wringer 13, the basket or drum 2 is introduced into the wringer, by means of a hoist of which only the hook 16 is shown in FIG. 2. The wringer 13 is provided heating means making it possible to reach a temperature of 150 ° C. and a tank 17 making it possible to drain and recover the excess impregnation material separated from the plugs.

From the above description, it is understood that the treatment method according to the invention completely breaks with the techniques of the prior art. In fact, in accordance with this process, the stopper is dehydrated followed by impregnation with an anhydrous material, preferably endowed with an antibiotic activity, which thus constitutes a real mummification of the stopper by making it perfectly tight and chemically inert. and biologically. The risk of contamination of the wine with substances liable to give it a "corky taste" or any other kind of false taste is thus completely eliminated.

It should also be noted that the moisture, which was judged necessary, in the processes of the prior art, to give the plug a compressibility allowing it to be placed in the neck is replaced by the impregnation material which 'It is enough to bring to an appropriate temperature, before bottling, to obtain the appropriate compressibility. This even makes it possible to carry out the plugging by means of the plugs treated by the process according to the invention more easily than by means of the plugs treated by the previously known processes.

On the other hand, thanks to their perfect tightness, the corks treated by the process according to the invention allow perfect control of the aging process of the wine in the bottle, allowing the obtaining of an optimal bouquet, programmed in advance. , and ensuring a long-term conservation, without surprise, in very clear progress compared to the case of the use of plugs of the prior art.

It has been found that the use of corks treated in accordance with the invention makes it possible to obtain bottled wines having an unsurpassed bouquet and whose taste presents an equal and regular quality for all the bottles of the same bottling. The commercial interest of this uniformity will not escape the specialist.

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Claims (19)

666,886 1. Process for treating cork stoppers, characterized in that the stoppers are dehydrated, that they are sterilized in an anhydrous state and that they are then impregnated with a material insoluble in water, the alcohol or their mixtures and inert towards them, this material being in the solid state at room temperature and being capable of softening gradually by heating and taking on a liquid consistency at a temperature below 120 ° C. and being, moreover, capable of being preserved without decomposition, at least for several years, in contact with air and under irradiation by sunlight or artificial light. 2. Method according to claim 1, characterized in that one simultaneously performs the dehydration of the plugs and their at least partial sterilization, by subjecting them to heating under reduced pressure. 2 3. Method according to claim 2, characterized in that the dehydration and sterilization operation by heating under reduced pressure comprises maintaining the plugs, for at least 90 minutes, at a temperature of 120 to 150 ° C, under pressure between 0.01 and 0.05 ■ 105 Pa. 4. Method according to one of claims 1 to 3, characterized in that, immediately after the dehydration and sterilization operation by heating under reduced pressure, and before the impregnation of the plugs with the impregnation material, it is maintained the stoppers under an inert gas atmosphere, anhydrous, under a pressure higher than the atomospheric pressure, at a temperature and for a period of time sufficient to allow their sterilization at heart. 5. Method according to claim 4, characterized in that said inert gas is carbon dioxide and in that the plugs are maintained for at least 30 minutes, at a temperature between 120 and 150 ° C, in the atmosphere of carbon dioxide under a pressure at least equal to 4 • 105 Pa. 6. Method according to one of claims 1 to 5, characterized in that the impregnation material consists of beeswax or a homogeneous mixture of beeswax and at least one inert substance. 7. Method according to claim 6, characterized in that the impregnation material consists of a mixture of 60 to 90 parts, by weight, of unrefined beeswax and 10 to 40 parts, by weight, of paraffin. 8. Method according to claim 7, characterized in that the mixture of beeswax and paraffin consists of 75 parts of wax and 25 parts of paraffin. 9. Method according to one of claims 1 to 5 and one of claims 7 or 8, characterized in that the plugs are impregnated by immersion in a bath of beeswax and paraffin mixture. maintained in the liquid state, at a temperature of 70 to 75 ° C. 10. Method according to claim 4 or claims 5 and 9, characterized in that, after sterilization at the heart of the plugs in the atmosphere of inert gas under pressure and immediately before their immersion in the beeswax mixture bath and paraffin, the pressure of the inert gas atmosphere is reduced to a value between 0.01 and 0.05 Pa, the plugs are allowed to cool to a temperature between 50 and 80 ° C and the the plugs are then immersed in the bath by introducing the mixture of wax and paraffin in the liquid state into the enclosure containing the atmosphere of inert gas under reduced pressure. 11. Method according to one of claims 1 to 10, characterized in that, after the impregnation of the plugs, the excess of impregnation material covering the external surface of the plugs is removed. 12. Method according to claim 10, characterized in that one carries out the removal of the excess impregnation material by spinning. 13. Installation for implementing the method according to claim 1, characterized in that it comprises a sealed treatment enclosure provided with heating means as well as means for establishing there, at will and alternately, an industrial vacuum and an atmosphere of pressurized inert gas, a removable basket capable of receiving a batch of plugs to be treated, this basket being arranged so that it can be placed, as desired, inside the treatment enclosure and removed from that with its load of plugs, a reservoir of impregnation material provided with heating means making it possible to carry and maintain this material in the liquid state and means for supplying the treatment enclosure with liquid impregnation material from this tank and to return this material to the tank from the processing enclosure. 14. Installation according to claim 13, characterized in that it further comprises a centrifugal wringer arranged so as to be able to receive said removable basket as a spinning drum, this wringer being provided with heating means and means for collecting the impregnation material of the plugs separated from them by wringing. 15. Installation according to claim 13 or 14, characterized in that the means for establishing the vacuum and the pressure in the enclosure comprise a urie suction and discharge pump also serving to circulate the liquid impregnation material between the reservoir of this material and the processing enclosure. 16. Stopper treated by the method according to claim 1. 17. Use of the stopper according to claim 16 for corking a bottle filled with a drink, characterized in that, prior to the establishment of the stopper in the neck of the bottle, the stopper is kept in the neck of the bottle, the stopper is kept at a temperature and for a sufficient time to soften the impregnation material, so as to give the stopper a flexibility suitable for its positioning in the neck. 18. Use according to claim 17, characterized in that said temperature is between 50 and 55 ° C and that the duration of holding the plug at this temperature is approximately 60 minutes. 19. Use according to claim 17 or 18, for the corking of a wine bottle, characterized in that, after filling the bottle and immediately before the establishment of the stopper in the neck, a stream of oxygen is blown on the free surface of the wine so that the volume between this surface and the cork contains 0.3 to 3 cm3 of oxygen, immediately after the cork is put in place.