A method for sealing wooden parts, in particular all or parts of a wooden container for the manufacture of alcoholic beverages.

Abstract

Method for sealing wooden parts, in particular all or parts of a wooden container for the manufacture of alcoholic beverages. The invention relates to a method for sealing wooden parts, in particular all or parts of a wooden container for the manufacture of alcoholic beverages, which includes at least one step of impregnating said wooden part with a liquid composition comprising a sealing compound.

Description

Title of the invention: Method for sealing a wooden part, in particular all or part of a wooden container for the manufacture of alcoholic beverages

[0001] The present invention relates to a method for sealing a wooden part, in particular all or parts of a wooden container which is used for the manufacture of alcoholic beverages.

[0002] In the context of the present invention, the term "alcoholic beverage" means an alcoholic beverage requiring at least one step in a wooden container during its manufacture. This alcoholic beverage may be chosen in particular from wines and spirits (for example, high-end spirits such as whisky, rum and wine brandy). The at least one step carried out in the wooden container may be a step chosen from the fermentation, maceration, aging, maturation or finishing steps.

[0003] The manufacture of alcoholic beverages as defined above requires wooden containers, generally made of oak or other types of wood (for example chestnut or acacia). Indeed, during aging in barrels, the extractable compounds of the wood diffuse into the alcoholic beverage (for example wine) and modify its aromas and taste, by providing more or less intense notes, for example of the “spicy”, “smoky”, “toasted” type, or simply by contributing to the aromatic complexity of the bouquet. On the other hand, the controlled oxidation of the substances present in the alcoholic beverage, caused by the penetration of oxygen through the barrel or pieces of wood of the container in contact with the alcoholic beverage, favorably modifies its organoleptic characteristics, as well as its color.

[0004] Wooden containers, depending on their shape and volume, may be, for example, barrels, casks, vats or tuns. This refers to any container commonly used for the manufacture of alcoholic beverages as defined above.

[0005] It is essential that wooden containers are airtight. Indeed, the lack of airtightness is highly detrimental, as it results in the loss of part of the alcoholic beverage during aging. Beyond the financial loss caused, the containers become dirty and this then degrades their aesthetic appearance. Leaks of alcoholic beverage can cause deterioration of the cellar environment (for example with the development of bacteria or yeasts). In addition, if the wooden containers lose small quantities of alcoholic beverage, because they are no longer completely full, this can, in certain cases, reduce the quality of the alcoholic beverage and cause the acceleration of evaporation and oxidation phenomena.

[0006] In order to ensure the watertightness of wooden containers, the production of staves (i.e. the boards which are the constructive elements of wooden containers) is based on a rigorous selection of wood: - when cutting the tree (the sapwood and bark are removed; radial cutting or splitting is preferred); - a selection is also carried out in the cooperage in order to remove all potentially “leaky” pieces (for example when the pieces of wood have knots, cracks or severed threads).

[0007] In addition, at the end of the manufacturing process of wooden containers, one or more liquid tightness tests are carried out. Generally, the test consists of filling the containers with water and observation by an experienced cooper of possible leaks. If leaks are detected, the container is repaired with or without replacement of the constituent parts (for example the staves). It is possible that despite these checks, the wooden container loses its tightness once placed in the cellar and filled with the must or the alcoholic beverage being manufactured. This requires repair of said wooden container and disrupts the manufacturing process of the alcoholic beverage. For example, this can disrupt the maturation stage.

[0008] It should be noted that complaints about leaking wooden containers are the leading cause of commercial non-conformity in cooperage (estimated at around 1% to 2% of barrels produced).

[0009] On a larger scale, the downgrading of pieces of wood due to potential lack of sealing (for example due to cut threads, cracks or small knots) constitutes the main source of loss of material yield and has a strong impact on the profitability of the cooperage business. Indeed, the wood used in cooperage is considered to be of the highest quality and reaches ever higher prices due to its rarity (trees over 100 years old, large diameters and often limited provenances). From an environmental point of view, the possibility of improving material yields also constitutes a virtuous approach for the cooperage industry and for wine and spirits producers.

[0010] Several technical solutions have been proposed to improve the sealing of wooden containers. A traditional sealing technique consists of introducing small pieces of wood into the areas of liquid leakage, which, by swelling, block the orifice(s) causing the leaks.

[0011] Another solution consists of applying to the external surface of the wooden container a product configured to block the leakage of liquid. For example, the product can be chosen from paraffins, varnishes, glues, as well as hygienic substances. drophobes (especially organic mastics) which are commonly used by coopers. The product can be applied manually with a brush or spatula or using a specific device. For example, it is known to use food paraffin which is heated and applied via a nozzle to the external surface of the wooden container which is placed under vacuum in order to promote the penetration of the food paraffin into the wood.

[0012] The disadvantages of these technical solutions are numerous. First of all, they require the use of qualified coopers and a significant intervention time which can limit the economic interest of the sealing operation. In addition, the treatments applied to the wood are localized and superficial: they do not ensure sealing over the entire depth of the staves or the timbers: the liquid can therefore, over time, bypass the superficial sealing, and thus a new leak can occur through other orifices that the wooden container may have.

[0013] The inventors sought to overcome the drawbacks of the sealing solutions known and used to date by developing a new method for sealing a wooden part, in particular a wooden container for the manufacture of alcoholic beverages, which is perfectly reliable, durable and simple to implement (for example in an autoclave).

[0014] The present invention thus relates to a method for sealing a wooden part, in particular all or parts of a wooden container for the manufacture of an alcoholic beverage, which is characterized in that it comprises at least one step of impregnating said wooden part with a liquid composition comprising at least one sealing compound.

[0015] The impregnation with the liquid composition comprising at least one sealing compound is carried out at the heart of the wood. This means that said liquid composition penetrates into the pores of the wood. Indeed, wood is a material naturally exhibiting high porosity.

[0016] After drying the wooden part and therefore after evaporation of a large part (or even all) of the liquid in the liquid composition, the sealing compounds that were present in said liquid composition create a seal (or in other words a "coating") that is impermeable to the wooden part. In other words, an inert and stable space is created on the wooden part thanks to the sealing compounds. This impregnation gives the wooden part a perfectly reliable and durable seal. Indeed, this impermeable coating on the wooden part prevents any risk of leakage, in other words any loss of alcoholic beverage.

[0017] In the context of the present invention, the wooden part may be all or part of a wooden container for the manufacture of an alcoholic beverage as defined above.

[0018] In embodiments of the invention, the wooden part may be a part of wood which has not been subjected to any machining before implementing the sealing process according to the invention and which will, after machining, be a constituent element of said wooden container (for example a stave or a base piece).

[0019] In other embodiments of the invention, the wooden part may be a part that has already been machined. It may, for example, be a machined wooden part that was intended to be a constituent element of a wooden container but on which a sealing defect was detected prior to the assembly of said wooden container. By way of non-limiting example, the wooden part may be a stave or a bottom part.

[0020] In other embodiments of the invention, the wooden part is a wooden container for the manufacture of an alcoholic beverage as defined above. It may for example be a vat, a tuna, a barrel or a cask.

[0021] Thus, the wooden piece can be a stave or a barrel stave of a vat, a barrel or a cask or a base piece for the manufacture of these containers.

[0022] In the context of the present invention, the wooden piece may be a stave, a beam, a base piece, a vat, a barrel, a tuns or a barrel.

[0023] The wooden part may be a raw material. This means that it has not been subjected to any chemical treatment.

[0024] In the context of the present invention, all the faces or part of the faces of the wooden part are impregnated with said liquid composition comprising at least one sealing compound.

[0025] In embodiments of the invention, at least the faces of the wooden part which are intended to be in contact with the alcoholic beverage are impregnated with said liquid composition comprising at least one sealing compound.

[0026] In order for said liquid composition to penetrate as well as possible into the pores of the wooden part, it is advantageous for the humidity level of the wooden part before the impregnation step to be less than 18%, more preferably less than 14%. If the wooden part has a humidity level greater than 18% before impregnation with the liquid composition comprising at least one sealing compound, the wooden part is advantageously subjected to a drying step (for example drying in the open air or in a drying oven with hot air circulation).

[0027] In the context of the present invention, all the constituents of the liquid composition must comply with the requirements of food regulations. This means that the constituents of the liquid composition are recognized by the Consumer Health Safety Authorities as being suitable for contact with foodstuffs. In other words, all the constituents of said liquid composition are compatible with food use.

[0028] The at least one sealing compound is therefore compatible with food use. mental.

[0029] The at least one sealing compound is recognized by the Consumer Health Safety Authorities as being suitable for contact with foodstuffs and / or authorized for the production of beverage aged in barrels.

[0030] The liquid(s) of the liquid composition are therefore compatible with food use.

[0031] The liquid(s) in the liquid composition are recognized by the Consumer Health Safety Authorities as being able to come into contact with foodstuffs.

[0032] The liquid composition advantageously comprises water and optionally at least one organic solvent, the nature and quantity of which are compatible with food use. Said solvent may be, for example, ethyl alcohol.

[0033] When the composition comprises at least one organic solvent, the ratio between the volume of water and the volume of said solvent may be between 1 and 50, preferably between 1 and 10.

[0034] The liquid composition further comprises one or more sealing compounds.

[0035] In embodiments of the invention, the sealing compound is a mineral compound.

[0036] The mineral compound is a mineral compound compatible with food use or in other words it is recognized by the Authorities in matters of consumer health safety as being able to be in contact with foodstuffs.

[0037] The mineral compound is configured to create a waterproof seal (in other words a coating) of said wooden part after drying thereof and therefore after evaporation of a large part (or even all) of the liquid in the liquid composition.

[0038] Preferably, the mineral compound has a higher solubility in water than in the alcoholic beverage. If the liquid composition comprises an organic solvent, said organic solvent can modulate the solubility of the mineral compound. This has the advantage that the liquid composition has a significant amount of mineral compounds dissolved therein. This allows the impregnation of the wooden part with a liquid composition highly concentrated in mineral compounds and therefore the penetration into the pores of the wood of a significant amount of mineral compounds which will create a waterproof seal (in other words a coating) of said wooden part. After drying the wooden part, because the mineral compounds are less soluble in the alcoholic beverage, the risk of migration of said mineral compounds into the alcoholic beverage is low. This thus contributes to the waterproofing of the wooden part.

[0039] In embodiments of the invention, the mineral compound has solubility in liquids (water, optionally organic solvent, and alcoholic beverage) which increases with heating of the liquid composition. In other words, it may be necessary to heat the liquid composition (i.e. increase the temperature of the liquid composition to a temperature above room temperature) so that all or part of the mineral compounds are dissolved therein. In these embodiments, the impregnation of the wooden part with the liquid composition is carried out by heating and maintaining said liquid composition at a temperature such that all or part of the mineral compounds are dissolved therein, in order to impregnate the wooden part with a maximum of mineral compounds which will create a watertight seal (in other words an inert and stable space between the wood and the alcoholic beverage) on the wooden part.Under the temperature conditions of the cellar (i.e. between approximately 10°C and 20°C), the mineral compounds are not soluble, or even very slightly soluble, in the alcoholic beverage, and there is therefore no risk of migration of said mineral compounds into the alcoholic beverage.

[0040] Advantageously, the concentration of mineral compounds in the liquid composition is such that said liquid composition is between 10% and 100%, preferably between 30% and 100%, more preferably between 50% and 100% of its saturation point in said mineral compounds. The liquid composition may be in the form of a heterogeneous solution with the solution phase saturated in part of the mineral compounds and the remainder of the mineral compounds in suspension. Such a concentration of mineral compounds allows impregnation of the wooden part which is suitable for making said wooden part waterproof.

[0041] The concentration of mineral compounds in the liquid composition may vary depending on the nature of said mineral compounds, namely depending on their solubility characteristics in liquids (water, where appropriate organic solvent, and the alcoholic beverage). Since a person skilled in the art has mastered the solubility characteristics of mineral compounds, it is perfectly within his reach to develop the liquid composition comprising mineral compounds at a determined concentration and, where appropriate, to heat it to a determined temperature, in order to be able to impregnate the wooden part with it and thus obtain a waterproof sealing (in other words a coating) of said wooden part.

[0042] The mineral compound can for example be chosen from: - magnesium, calcium or aluminum hydroxides; - manganese, calcium or zinc sulfides; - carbonic acid salts selected from magnesium, calcium, manganese, copper, zinc or silver carbonates; - sulfurous acid salts selected from calcium sulfites; - phosphoric acid salts selected from magnesium, calcium or aluminum phosphates; - tartaric acid salts selected from potassium, calcium or magnesium tartrates and bitartrates; - meta-silicic acid salts selected from potassium, sodium, magnesium or calcium silicates; - acetic acid salts selected from aluminum acetates; - oxalic acid salts selected from magnesium or calcium oxalates; - fatty acid salts selected from magnesium or calcium fatty acid salts, taken alone or as a mixture thereof.

[0043] These mineral compounds may be present alone or as a mixture of these in the liquid composition.

[0044] Preferably, the mineral compound is potassium bitartrate or sodium silicate.

[0045] In a preferred embodiment of the invention, the mineral compound is potassium bitartrate. It has the advantage of having a solubility in water which increases with increasing temperature: 5.7g / L at 20°C (i.e. room temperature), 45g / L at 80°C and 61g / L at 100°C. The impregnation of a wooden part with a liquid composition comprising this mineral compound can advantageously be carried out by maintaining said liquid composition at a temperature between 20°C and 60°C. Then, after drying, the solubility of this mineral compound being very low at room temperature, there is no risk of it dissolving in the alcoholic beverage maintained at a temperature between 10°C and 20°C, i.e. the room temperature of the cellar. Moreover, by its nature, wine is a saturated solution of potassium bitartrate.This is why, due to this saturation, the potassium bitartrate crystals formed within the wooden piece cannot dissolve in the wine. These crystals of mineral compounds are not likely to be released into the wine, they constitute a waterproof seal (in other words a coating) of the wooden piece and thus guarantee its watertightness.

[0046] In other embodiments of the invention, the sealing compound is an organic sealing compound. This organic sealing compound is compatible with food use or, in other words, it is recognized by the Authorities in matters of consumer health safety as being able to come into contact with foodstuffs.

[0047] The organic sealing compound is an organic compound configured to create a waterproof seal (in other words a coating) of said wooden part after drying thereof and therefore after evaporation of a large part (or even all) of the liquid in the liquid composition.

[0048] Advantageously, the organic sealing compound is an organic compound whose physicochemical properties change under the effect of a heating (for example to a temperature between 20°C and 160°C) so as to improve its sealing capacity. These modifications of the physicochemical properties may, for example, consist of a rearrangement of the polymer chains of the organic sealing compound when it is a polymer.

[0049] The at least one organic sealing compound may be chosen from the following compounds: - polysaccharides (e.g. alginates, alginic acids, pectins, starches, gum arabic), - biopolymers (e.g. chitosan), - citric acid, - gelling compounds (e.g. agar-agar, gelatins, carboxymethylcellulose), - mannoproteins (i.e. molecules derived from yeast), - fish glues, - proteins of plant origin (for example, cereal or pea proteins), taken alone or in a mixture of these.

[0050] In these embodiments of the invention, it is advantageous for the liquid composition to comprise at least one organic solvent (for example ethanol). This will facilitate and improve the impregnation of the wooden part with the liquid composition. Indeed, the organic sealing compounds will be well dissolved in the liquid comprising at least one organic solvent of the liquid composition. The use of organic solvent (for example ethanol) can also contribute to improving the solubility and reactivity of the sealing compounds.

[0051] In embodiments of the invention, the liquid composition may comprise a mixture of mineral compounds as described above and organic sealing compounds as described above.

[0052] Thus, within the framework of the present invention, the sealing compound may be a mineral compound and / or an organic sealing compound which is recognized by the Authorities in matters of consumer health safety as being able to be in contact with foodstuffs and / or authorized for the production of beverage aged in barrels.

[0053] As explained above, when the sealing compounds are mineral compounds, the temperature to which the liquid composition is subjected for impregnating the wooden part may depend on the solubility of said mineral compounds that said liquid composition comprises. The same may apply to organic sealing compounds as described above: the temperature to which the liquid composition is subjected for impregnating the wooden part may depend on the solubility of the organic sealing compounds that said liquid composition may include.

[0054] Therefore, during the impregnation of the wooden part with the liquid composition, said liquid composition may be subjected to a temperature of between 10°C and 140°C. In one embodiment, this temperature is room temperature (approximately 20°C). In another embodiment of the invention in which the liquid composition is kept under pressure during the impregnation, the temperature to which the liquid composition is subjected may be greater than 100°C and at most 140°C.

[0055] Preferably, the sealing method according to the invention is carried out in an autoclave.

[0056] Indeed, the autoclave is a device commonly used for the treatment of wooden parts. It comprises an enclosure which is configured to place the wooden parts to be treated therein and which can be hermetically sealed so as to be resistant to vacuum and pressure. This is why the sealing process has the advantage of being easily implemented due to the use of devices conventionally used in the treatment of wood.

[0057] Of course, the sealing method according to the invention can be carried out in other devices equivalent to the autoclave which comprise an enclosure configured to place the wooden part there and be hermetically closed (for example, tanks or baths).

[0058] In embodiments of the invention, the sealing method is implemented with a device called an “impregnation device”, such as an autoclave or other equivalent device, which comprises an enclosure configured to place the wooden part therein and be hermetically closed, the impregnation of the wooden part is carried out by: a) placing said wooden part in the enclosure of said impregnation device and closing it hermetically, (b) filling said enclosure with liquid composition in such a quantity that all or part of said wooden piece is immersed in said liquid composition, (c) allowing the impregnation to take place for a specified period of time.

[0059] The duration of step c) during which the impregnation is allowed to take place may advantageously be between 30 minutes and 12 hours.

[0060] During step b) of filling the enclosure with the liquid composition, the temperature within said enclosure may be between 10°C and 100°C. For example, this temperature may be ambient temperature (approximately 20°C). In other embodiments of the invention in which the liquid composition needs to be heated, the temperature of the enclosure of the impregnation device may be higher than ambient temperature.

[0061] During step c) of impregnating the wooden part with the liquid composition, the temperature within the enclosure of the impregnation device may be between 10°C and 140°C. For example, this temperature may be room temperature (approximately 20°C). In other embodiments of the invention in which the liquid composition needs to be heated, the temperature of the enclosure of the impregnation device may be higher than room temperature.

[0062] In order to be able to heat the liquid composition during steps b) and c), the enclosure may be equipped with heating means. These may, for example, be heating elements arranged inside said enclosure. In addition, the enclosure may be provided with a double wall in order to prevent heat loss.

[0063] Furthermore, as explained above, all the sealing compounds (namely the mineral compounds and / or the organic sealing compounds) may not always be all dissolved in the liquid composition when carrying out steps b) and c). This is why, advantageously, a paddle stirrer or a pump is present inside the enclosure of the impregnation device in order to keep in suspension said sealing compounds which are not dissolved in the liquid composition.

[0064] Advantageously, the sealing method comprises a preliminary step before impregnating the wooden part with the liquid composition which consists of eliminating all or part of the air present in the porosity of the wooden part by exposing said wooden part to a vacuum.

[0065] Therefore, in one embodiment of the invention, the wooden part is exposed to a vacuum for a period of between 10 minutes and 3 hours and such that the pressure is between 0.05 bars and 0.5 bars. This preliminary step of removing the air present in the porosity of the wooden part can also be carried out in the enclosure of the impregnation device as described above (namely autoclave or equivalent device).

[0066] The implementation of this preliminary step, namely the parameters of duration and adjustment of the vacuum are perfectly within the reach of a person skilled in the art. Indeed, in the processes for treating wooden parts which are carried out in particular in autoclaves or equivalent devices, it is perfectly common to remove the air present in the structure of the wood by exposing it to a vacuum before implementing said treatment.

[0067] In embodiments of the invention in which a vacuum has been created prior to impregnation to remove as much air as possible from within the wooden structure, the vacuum can be maintained during step b) of filling the enclosure with the liquid composition, or even during step c) during which the wooden part is left to be impregnated with the liquid composition. to be carried out.

[0068] In embodiments of the invention, step b) of filling the enclosure with the liquid composition can be carried out by pressurizing said liquid composition. The injection pressure of the liquid composition can be between 5 bars and 20 bars. The pressurization of the liquid composition can for example be carried out using a pump or a press.

[0069] In embodiments of the invention, during step b) of filling the enclosure with the liquid composition, a pressure, preferably a pressure of between 5 bars and 20 bars, can be established within the enclosure of the impregnation device.

[0070] In embodiments of the invention, during step b) of filling the enclosure with the liquid composition, no pressure is established within the enclosure of the impregnation device. In other words, in these embodiments of the invention, the filling of the enclosure is carried out at atmospheric pressure.

[0071] In embodiments of the invention, during step c) during which the impregnation of the wooden part is allowed to take place, a pressure, preferably a pressure of between 5 bars and 20 bars, is advantageously established within the enclosure of the impregnation device.

[0072] Maintaining the vacuum during step b) of filling the enclosure, or even during step c) of impregnation, introducing the liquid composition under pressure during step b) or subjecting the wooden part to a determined pressure during steps b and / or c) are different means which make it possible to impregnate the wooden part as best as possible with the liquid composition or in other words means which make it possible to introduce the liquid composition as best as possible into the wooden part. These conditions of vacuum drawing or maintaining the wooden part at a determined pressure make it possible to ensure sufficient solubility of the sealing compounds (namely mineral compounds and / or organic sealing compounds), satisfactory fluidity of the liquid composition and effective penetration of the liquid composition into the natural porosity of the wooden part.

[0073] When, during step c), a determined pressure has been applied for a determined duration to the wooden part in order to improve its impregnation with the liquid composition, the pressure is then brought back to atmospheric pressure, preferably gradually.

[0074] In embodiments of the invention, all the steps of the sealing method can be carried out within the enclosure of an impregnation device which can be an autoclave or a device equivalent to the autoclave which comprises an enclosure configured to place the wooden part therein and be hermetically sealed. In these embodiments, said method of sealing a wooden part includes at least the following steps: - the said wooden piece is placed in the enclosure of the said impregnation device and it is hermetically sealed, - optionally, all or part of the air present in the porosity of the wooden part is eliminated by exposing said wooden part to a vacuum, - said enclosure is filled with a liquid composition comprising at least one sealing compound as described above in a quantity such that all or part of said wooden part is immersed in said liquid composition, - impregnation is allowed to take place for a determined period.

[0075] The characteristics and parameters of each of these steps are the same as those described above.

[0076] Finally, the excess liquid composition (i.e. the liquid composition that has not been retained by capillarity in the pores of the wooden part) can be removed. Different means, perfectly within the reach of a person skilled in the art, can be implemented to remove the excess liquid composition. This involves, for example, draining the wooden part thus obtained at the end of the impregnation, for example by tilting it, or pumping out the excess liquid composition. It may also involve keeping said part in the enclosure of the impregnation device and exposing it to a vacuum for a determined period (for example under the conditions as described above for the step prior to impregnation). These different means for removing excess liquid composition can be implemented alone or in combination with each other.

[0077] At the end of the sealing process according to the invention, the wooden part thus obtained can continue a traditional process for manufacturing wooden containers for the manufacture of alcoholic beverages.

[0078] The sealed wooden part obtained with the sealing process according to the invention can thus be dried, then machined before its assembly to obtain a wooden container for the manufacture of alcoholic beverages.

[0079] In this regard, in preferred embodiments of the invention and when the sealing compound is an organic sealing compound as described above, the sealed wooden part is then subjected to a heating step, for example at a temperature of between 20°C and 160°C and for a period of between 5 minutes and 24 hours. This provides the advantage of improving the sealing power of said organic sealing compound. Indeed, organic sealing compounds as described above can be transformed under the effect of heat (in other words their physicochemical properties change under the effect of heating); which leads to an improvement in their capacity to seal the wooden part.

[0080] This heating step can for example be carried out in an oven or in a convection oven or any other equivalent heating device.

[0081] The invention will be better understood with the aid of the examples detailed below.

[0082] Example 1:

[0083] 10 m3 of pallets of staves (dimensions: thickness 27 mm, length: 950 mm, width: between 30 and 100mm) were placed in an autoclave comprising a cylindrical horizontal chamber 1.8 m in diameter and 12 m in length (30 m3). The autoclave chamber was hermetically sealed. A vacuum (0.15 bars) was established in the autoclave chamber and maintained for 30 minutes in order to remove the air present in the pores of these wooden pieces.

[0084] A first aqueous composition containing potassium bitartrate at a concentration of 10 g / L was prepared. A portion of the bitartrate salts remained insoluble and were kept in suspension using a stirrer in the preparation tank of the first aqueous composition until 30 m3 of it was introduced into the autoclave enclosure, at room temperature (approximately 20°C) and while maintaining the vacuum established.

[0085] Then, the pressure within the autoclave enclosure was increased to 12 bars using a pump and maintained for a period of 90 minutes during which the first aqueous composition was allowed to impregnate the wooden parts.

[0086] The pressure within the autoclave was gradually lowered to atmospheric pressure and the excess of the first aqueous composition was removed by pumping.

[0087] Finally, a vacuum of the autoclave enclosure at 0.5 bars was established in order to eliminate the final residues of the first aqueous composition.

[0088] The autoclave enclosure was opened and the pallets of staves thus sealed were removed for complete drying.

[0089] The pallets of staves were air dried to a moisture content of 14-16%.

[0090] The pallets of staves were machined and then used for the manufacture of barrels.

[0091] Example 2:

[0092] 10 m3 of pallets of barrel bottom parts (dimensions: thickness: 27 mm and length between 400 and 600 mm, width: 30-100 mm) were placed in the same autoclave enclosure as for example 1. The autoclave enclosure was hermetically sealed.

[0093] A vacuum (0.15 bars) was established in the autoclave enclosure and maintained for 30 minutes in order to remove the air present in the pores of these wooden pieces.

[0094] 20 m3 of a 2nd aqueous composition of potassium bitartrate at a concentration of 50 g / L was used as an impregnation product. The said 2nd composition aqueous composition was heated to a temperature of 80°C. Some of the bitartrate salts remained insoluble and were kept in suspension using a stirrer in the preparation tank of the 2nd aqueous composition until the 20 m3 of the latter was introduced into the autoclave enclosure, while maintaining the preparation tank and the 2nd aqueous composition at a temperature of 80°C.

[0095] During the filling of the autoclave enclosure with the 20 m2 of the 2nd aqueous composition, the established vacuum of 0.15 bars was maintained and the temperature within the autoclave enclosure was set at 80°C. To do this, the enclosure was provided with a double wall in order to avoid heat loss and heating elements were arranged inside said enclosure. The potassium bitartrate salts which remained insoluble were kept in suspension in the 2nd aqueous composition by means of a submerged pump present inside the autoclave enclosure.

[0096] Then, the pressure within the autoclave enclosure was increased to 12 bars using a pump and maintained for a period of 90 minutes during which the 2nd aqueous composition was allowed to impregnate the wooden parts.

[0097] The pressure within the autoclave was gradually lowered to atmospheric pressure and the excess of the 2nd aqueous composition was removed by pumping.

[0098] Finally, a vacuum of the autoclave enclosure at 0.5 bars was established in order to eliminate the final residues of the 2nd aqueous composition.

[0099] The autoclave enclosure was opened and the pallets of sealed base pieces were removed for complete drying.

[0100] The pallets of bottom pieces were air dried to a moisture content of 14-16%.

[0101] The bottom piece pallets were machined and then used for the manufacture of barrels.

[0102] Example 3:

[0103] 20 m3 of pallets of parts for the manufacture of large wooden vats (dimensions: thickness 54 mm and length between 1500 and 2000 mm, width 100-500 mm) were placed in the same autoclave enclosure as for example 1. The autoclave enclosure was hermetically sealed.

[0104] A vacuum (0.15 bars) was established in the autoclave enclosure and maintained for 30 minutes in order to remove the air present in the pores of these wooden pieces.

[0105] 30 m3 of a 3rd aqueous composition of sodium silicate at a concentration of 150 g / L were prepared.

[0106] The autoclave enclosure was filled with 30 m3 of this 3rd aqueous composition, at room temperature (approximately 20°C) and maintaining the established vacuum.

[0107] Then, the pressure within the autoclave enclosure was increased to 9 bars using a pump and maintained for a period of 45 minutes during which the 3rd aqueous composition was allowed to impregnate the wooden parts.

[0108] The pressure within the autoclave was gradually (over a few minutes so as not to damage the sealed parts) lowered to atmospheric pressure and the excess of the 3rd aqueous composition was removed by pumping.

[0109] Finally, a vacuum of the autoclave enclosure at 0.5 bars was established in order to eliminate the final residues of the 3rd aqueous composition.

[0110] The autoclave enclosure was opened and the pallets of parts for the manufacture of large wooden vats thus sealed were removed for complete drying.

[0111] Said pallets were dried in the open air until they had a humidity level of 17-18%, then they were placed in a dryer so as to be heated to 35°C with hot air circulation until they had a humidity level of 14-16%.

[0112] Said pallets were machined and then used for the manufacture of large wooden vats.

[0113] Example 4:

[0114] Barrels (volume 225 L) which had been discarded during the manufacture of wooden containers due to a lack of sealing (i.e. they had leaks) following a sealing test were subjected to the sealing process according to the invention.

[0115] More precisely, the leak test consisted of injecting 7 liters of hot water (at 70°C) into each of these drums under a pressure of 0.2-0.5 bars. The water injected into the drums was subjected to rotation / mixing with a wheel system for 2 minutes so that the water was in contact with the entire internal surface of these drums. This made it possible to detect, by visual observation, any leaks present on these drums.

[0116] The non-watertight barrels were dismantled to recover their non-watertight wooden parts (for example the staves and bottom parts). These parts thus recovered were subjected to the sealing process according to the invention, in the same manner as in Example 1 described above. The parts subjected to the sealing process according to the invention were reassembled to obtain the barrels again.

[0117] Then, the leak test was again carried out on each of the drums. It was found that: 60% of the drums were now perfectly leakproof, 30% of the drums had leaks but to a lesser extent than before the implementation of the sealing method according to the invention. Finally, 10% of the drums remained leakproof.

[0118] The sealing method according to the invention has therefore made it possible to improve sealing of drums in 90% of cases. This is an excellent result compared to the other known sealing solutions mentioned above, which improve sealing in around 50% of cases.

Claims

Claims

1. Method for sealing all or parts of a wooden container for the manufacture of an alcoholic beverage, comprising at least one step of impregnating all or parts of said wooden container with a liquid composition comprising at least one mineral and / or organic sealing compound which is recognized by the Authorities in matters of consumer health safety as being suitable for contact with foodstuffs and / or authorized for the production of beverage aged in barrels, characterized in that: - the mineral compound is chosen from tartaric acid salts selected from potassium, calcium or magnesium tartrates and bitartrates, and - the organic compound is chosen from: alginates, alginic acids, pectins, gum arabic, chitosan, citric acid, gelling compounds such as agar-agar, gelatins, carboxymethylcellulose, mannoproteins, fish glues,proteins of plant origin, taken alone or in a mixture of these.,

2. Method for sealing a wooden part according to claim 1, characterized in that said wooden part is a stave, a beam, a bottom piece, a vat, a barrel, a tuns or a barrel.

3. Method for sealing a wooden part according to claim 1 or 2, characterized in that the humidity level of said wooden part before the impregnation step is less than 18%.

4. Method for sealing a wooden part according to any one of the preceding claims, characterized in that the liquid composition comprises water and optionally at least one organic solvent.

5. Method for sealing a wooden part according to any one of the preceding claims, characterized in that the mineral compound is potassium bitartrate.

6. Method for sealing a wooden part according to any one of the preceding claims, characterized in that during the impregnation of the wooden part with the liquid composition, said liquid composition is subjected to a temperature between 10°C and 140°C.

7. Method for sealing a wooden part according to any one of the preceding claims, characterized in that it is implemented with a device called an "impregnation device", such as an autoclave, which comprises an enclosure configured to place the wooden part therein and be hermetically sealed and in that the impregnation of the wooden part is carried out by: a) placing said wooden part in the enclosure of said impregnation device and closing it hermetically, b) filling said enclosure with liquid composition in a quantity such that all or part of said wooden part is immersed in said liquid composition, c) allowing the impregnation to take place for a determined period.

8. Method for sealing a wooden part according to any one of the preceding claims, characterized in that it comprises a preliminary step before impregnating the wooden part with the liquid composition which consists of eliminating all or part of the air present in the porosity of the wooden part by exposing said wooden part to a vacuum.

9. Method for sealing a wooden part according to claim 7, characterized in that during step c) during which the impregnation of the wooden part is allowed to take place, a pressure, preferably a pressure of between 5 bars and 20 bars, is established within the enclosure of the impregnation device.

10. Method for sealing a wooden part according to any one of claims 1 to 9, characterized in that when the sealing compound is an organic sealing compound, the sealed wooden part is then subjected to a heating step at a temperature of between 20°C and 160°C and for a duration of between 5 minutes and 24 hours.