FR3026337A1 - PROCESS FOR TREATING WOODEN PIECES AND THEIR USE IN THE MANUFACTURE OF WINES AND SPIRITS, OR EXTRACTS OF WOOD OR WOOD CONTAINERS - Google Patents

Abstract

The invention relates to a method for treating pieces of wood, preferably oak, comprising the following steps: (a) drying of the pieces of wood, (b) mechanical transformation, and (c) optionally heating, in which a heating step (d) is carried out under an inert atmosphere, at a temperature ranging from 10 to 120 ° C. and at a pressure ranging from 1 to 60 MPa (10 to 600 bar), this step (d) being carried out after step (a), (b) or (c). It also relates to the use of the pieces of wood thus obtained in the manufacture of wines and spirits, or wood extracts, including wooded waters, and wooden containers.

Description

The present invention relates to a process for the treatment of pieces of wood, preferably oak, comprising a method of treating pieces of wood and their use in the manufacture of wines and spirits, or wood extracts, or wooden containers, comprising a particular heating step, as well as the oenological product obtained by this process and its use in the manufacture of wines and spirits, wood extracts and still barrels and casks. "Spirits" means an alcoholic beverage obtained by distillation, followed optionally by maceration or infusion of agricultural raw materials. These manufacturing processes distinguish spirits from alcoholic beverages produced by fermentation such as wine. Spirits are divided into two main families: - "simple" spirit drinks, more commonly known as eaux-de-vie, whose taste comes directly from the distillation process, such as cognac, vodka, rum, whiskey and tequila; - "compound" spirit drinks, whose taste is derived from vegetable substances, sugar or flavorings, added to a neutral alcohol or a brandy, such as liqueurs and aniseed liqueurs. In the field of oenology, pieces of wood, especially Quercus-type oak, are used in the production of wines and spirits, in the preparation of wood extracts and in the manufacture of containers such as barrels and barrels. barrels, for their storage. In particular, pieces of wood in the form of chips, aggregates or staves are used in the production of wines and spirits. They are then put in contact with wines and spirits for a period of 5 days to 12 months, before, during or after fermentation. This contact allows the extraction of molecules that can bring fruity notes, woody aromas, a gain in complexity, sweetness and / or tannic structure. This technique is regulated by European Community Regulation No. 1507/06 of 10 July 2009.

Another use of the pieces of wood is the preparation of dry wood extracts or not. For example, they can be obtained by macerating pieces of wood in water or other solvents, followed by concentration and spray-drying, lyophilization or other technique. The dried extracts of wood can be used in various fields such as the food, pharmaceutical or cosmetic industry. In particular, in the field of oenology, dried extracts of wood are known under the name of "oenological tannin", which is used in the production of wines and spirits to facilitate the clarification of musts and wines, for example in an amount of 0.1 to 1 g / l. of wine or spirits. They must not change the olfactory properties and the color of the wines. Another example of wood extract consists of woody waters that are obtained during the maceration, for example, of oak chips in boiling water, then concentration by evaporation. These wooded waters are then used in the assembly of spirits. Different kinds and quantities of pieces of wood are used depending on the desired intake of extractable compounds from oak wood. Finally, pieces of wood in the form of staves or staves can also be used for the manufacture of containers, such as barrels and barrels. These are used for fermentation, aging and storage of wines and spirits. During the stay of wines and spirits in wooden containers, they are enriched with the extractable compounds of the wood, which are extracted towards the wine / spirits and modify in a beneficial way their organoleptic characteristics.

As examples of wood used, there may be mentioned those from oak of different species of Quercus. In Europe, the two species generally used are sessile oak (Quercus petraea) and pedunculate oak (Quercus robur). Both species are widespread in French forests. There are also other botanical species used periodically for the production of pieces such as Quercus frainnetto (Balkans, Hungary, northern Italy), Quercus pyrenaica and Quercus faginea (Spain).

Other species of oaks that come from North America can also be used. By way of examples, there may be mentioned the American white oak, represented mainly by the botanical species Quercus alba L. and other closely related species such as Q. prinus L., Q. bicolor Wild. and Q. macrocarpa Michx.

Finally, other species of wood can still be used in the manufacture of pieces, such as acacia, cherry or chestnut, etc .... They will be chosen according to their contribution of extractable compounds, beneficial for the aroma and the taste of wines and spirits. Pieces of wood intended especially for the production of wines and spirits and the preparation of wood extracts can be obtained from logs and wooden blocks, as well as from by-products of the processing industry. ironwork and cooperage as pieces of wood unsuitable for the manufacture of staves, delignings, cuts and parts downgraded.

The pieces of wood contain molecules that are extractable compounds allowing the strengthening of fruity notes, the contribution of woody aromas, the gain in complexity, sweetness and / or tannic structure (hereinafter referred to as "molecules with an interest in oenology"). "), But also molecules responsible for unwanted tastes in wine or spirits, which can be called" plank "," sawdust "," mushroom "or" musty ". These molecules modify and cover the natural aroma of wine, and we speak of "lack of frankness" or "lack of sharpness". These molecules are called "deviation markers".

Examples of such deviation markers include E- (trans) -2-nonenal, 3-octen-1-one, E- (trans) -2-octenal and 1-decanal. and as precursors of deviation markers, oleic, linoleic and palmitic acids.

Methods are known in the art for removing these deflection markers from wood chips. For example, heating and / or washing may be mentioned. By "heating" is meant heating of the pieces of wood at a temperature ranging from 50 to 300 ° C, preferably from 70 to 250 ° C, in the presence of air at atmospheric pressure. However, the heating can not be applied to all pieces of oak because there are demands on the oenological market for unheated pieces of wood. These are for example, very used in the fermentation of wines, introduction to the stage of wine breeding or in the production of spirits. In addition, some molecules can degrade during heating and become markers of deviation. This is particularly the case of linoleic acid which is transformed into trans-2-nonenal under the action of temperature. Thus the heating can not be effective to eliminate all the molecules responsible for deviations and in some cases can even cause their formation. Washing, for its part, is characterized by two important disadvantages. On the one hand, washing with organic solvents can lead to the possible presence of traces of solvents in the finished product, and thus present toxicological risks. On the other hand, washing with non-toxic products, commonly used in oenology, such as water and ethanol, extracts few deviation markers, and at the same time extracts molecules with an interest in oenology such as tannins, furan compounds or vanillin. This extraction impoverishes the pieces of wood and renders them ineffective for their initial purpose of use, namely in particular the contribution of woody flavors and sweetness. There is therefore a need for a method for obtaining pieces of wood free of deflection markers while limiting the loss of molecules of interest oenological, or retaining their initial content. The Applicant has surprisingly found that the method of treating pieces of wood, preferably oak, comprising the following steps: (a) drying pieces of wood, (b) mechanical processing, and (c) optionally heating, in which a heating step (d) is carried out under an inert atmosphere, at a temperature ranging from 30 to 120 ° C and at a pressure ranging from 1 to 60 MPa (10 to 600 bar), this step (d) being performed after step (a), (b) or (c), overcomes the disadvantages mentioned above. This heating step (d) under an inert atmosphere, for example in the presence of CO2, which is preferably in the supercritical state, leads to an effective removal of markers of deviation of the pieces of wood without damaging the raw material, and without depleting the pieces of wood in extractable molecules of oenological interest. It is also possible to eliminate precursor compounds, such as linoleic acid, which can after conventional heating, generate compounds causing deviation, such as trans-2-nonenal. In addition, step (d) of heating can be applied: - on the pieces of dried wood, that is to say after step (a), - on the pieces of processed wood, that is to say ie after step (b), or - on the heated pieces of wood, i.e. after step (c). This method of treating pieces of wood thus makes it possible to produce pieces of wood, preferably oak, the amount of deviation markers is significantly reduced, while limiting the loss of molecules of interest to oenology, by eliminating dietary risks and not damaging the raw material. The subject of the invention is therefore a process for treating pieces of wood, preferably oak, comprising the following steps: (a) drying the pieces of wood, (b) mechanical transformation, and (c) optionally heating in which a heating step (d) is carried out under an inert atmosphere at a temperature ranging from 30 to 120 ° C and a pressure of from 1 to 60 MPa (10 to 600 bar), this step (d) being performed after step (a), (b) or (c). The invention also relates to an oenological product consisting of the pieces of wood that can be obtained by the process according to the invention. Another subject of the invention relates to the use of the oenological product according to the invention in combination with a must, a wine, a spirit, water, one or more solvents such as ethanol, or a water / solvent mixture. (s).

The invention also relates to a composition comprising in a medium, such an oenological product preferably in an amount ranging from 0.5 to 100 g / l of medium, said medium being a must, a wine, a spirits, water , one or more solvents, such as ethanol, or a water / solvent mixture (s).

The invention also relates to a process for the manufacture of wines and spirits, or wood extracts, using the method of treating pieces of wood according to the invention. Another object of the invention relates to a method of manufacturing wooden containers such as barrels and barrels, for the breeding of wines and spirits, implementing the method of treating pieces of wood according to the invention. Other objects, features, aspects and advantages of the invention will emerge even more clearly on reading the description and examples which follow.

In what follows, and unless otherwise indicated, the boundaries of a domain of values are included in this field, especially in the expressions "between" and "from ... to".

Moreover, the expression "at least one" used in the present description is equivalent to the expression "one or more". The method of treating pieces of wood, preferably oak, according to the invention, comprises the following steps: (a) drying the pieces of wood, (b) mechanical transformation, and (c) optionally heating, in which is carried out a heating step (d) under a neutral atmosphere, at a temperature ranging from 30 to 120 ° C and at a pressure ranging from 1 to 60 MPa (10 to 600 bar), this step (d) being performed after step (a), (b) or (c). The treatment method according to the invention uses pieces of wood, preferably oak. These pieces can be in the form of staves, logs or studs. They may also come from by-products of the stonemasonry and cooperage industry, such as pieces of wood that are unsuitable for the manufacture of staves, edgings, scabs, and decommissioned parts. In step (a), the pieces of wood are dried in the open air and / or in ovens to reduce the moisture content of the pieces of wood. This moisture content is generally from 50 to 60% by weight relative to the total weight of pieces of wood at the time of cutting the trees, and this step (a) makes it possible to obtain a humidity level ranging from 6 to 20% by weight relative to the total weight of pieces of wood. This moisture content can be measured by conductimetry or by comparison of the weight before and after drying in an oven at 105 ° C. During drying, various chemical reactions occur such as hydrolysis, oxidation and / or polymerization, different physical (leaching, extraction, ...) and microbiological (enzymatic reactions) transformations of the constituents of the pieces of wood. These modifications contribute to the increase of the oenological quality of the pieces of wood. This step (a) can also be called a "maturation" stage. By "oenological quality" is meant the ability of the pieces of wood to yield wines and spirits molecules with an interest in oenology. Stage (a) is generally in the open air for a period of 6 to 36 months, better 12 to 36 months. Watering with water can be done however in some cases to promote ripening and to compensate for lack of water during hot summers. Step (a) may also be carried out in an oven heated to a temperature ranging from 20 to 40 ° C, or better still from 25 to 35 ° C, in particular by circulating hot air, for example for 5 to 30 days, more particularly from 10 to 20 days. The use of an oven can also complete the drying in the open air to reduce the duration of this step and / or adjust the hygrometry of the pieces of wood at the end of the stage. Step (b) consists in mechanically transforming the pieces of wood, for example by grinding, sieving, sawing, cutting, shaping and other operations specific to woodworking. These different mechanical transformations lead in particular to powder, aggregates, chips, boards and staves. For example, the grinding makes it possible to obtain powders in particular with a particle size of about 0.2 to 1 mm, better still 0.3 to 0.5 mm, or chips having a linear dimension (dimension corresponding to the greatest length). ranging from 2 mm to 7 cm, better from 5 mm to 5 cm. Another example is the cutting of rough staves which leads to staves corresponding to pieces of wood of length 90 cm to 115 cm, thickness 1 to 50 mm, better from 20 mm to 40 mm, and width 5 to 40 cm. Step (c) is optional. There are pieces of wood used in oenology, which do not undergo heating.

This step (c) consists in heating the pieces of wood at a temperature ranging from 50 to 300 ° C., preferably from 70 to 250 ° C., for 5 minutes to 32 hours, better still from 10 minutes to 24 hours, in the presence of air, under atmospheric pressure.

In one embodiment, step (c) is preferably at a temperature of 140 ° C to 250 ° C for a period of 10 min. at 24 hours. In another embodiment, it is at a temperature of 70 to 120 ° C for a period of 10 min. at 10 o'clock. Step (c) may be carried out as follows: - with a wood fire, - with an oven by convection of hot air, - with infra-red radiation, or - by contact with a heated surface , for example of the coffee roasting drum type. According to the invention, the heating step (d) is carried out under an inert atmosphere at a temperature ranging from 30 to 120 ° C, preferably from 40 to 80 ° C, under a pressure of 1 to 60 MPa 600 bar), better 10 to 30 MPa (100 to 300 bar). The inert atmosphere is an inert gas, preferably carbon dioxide. In a particular embodiment, the latter is in a dense state under pressure, better in the supercritical state.

In step (d), carbon dioxide gas, for example, is used under normal conditions of temperature and pressure, and its density is increased by increasing its pressure. By changing the temperature also, we will place ourselves in the field where the carbon dioxide is in the supercritical state. This domain can be determined by those skilled in the art. According to the invention, during step (d), compression / decompression cycles can be performed to improve the penetration performance of the fluid in the pieces of wood.

Thus according to the invention, it is possible, during the treatment, to carry out compression / decompression cycles, preferably very rapid cycles with, for example, an amplitude of the pressure variation of 10 to 100 bar, and time intervals of 1 second to a few minutes, for example, 10 minutes, all, for example, for 1 to a few hours, for example, 10 hours. This heating step (d) can be applied: on the dried pieces of wood, that is to say after step (a), on the processed pieces of wood, that is to say after step (b), or - on the heat-treated pieces of wood, that is to say after step (c), and preferably after step b) or after step c). This step (d) can be carried out in the presence of a co-solvent It can be chosen, for example, from water, ethanol, and mixtures thereof. The cosolvent can then be used in an amount ranging from 0.01 to 10% by weight, preferably from 0.02 to 1% by weight, better still from 0.02 to 0.1% by weight relative to the weight. of inert gas used.

This step (d) is carried out for a period of preferably from 10 minutes to 24 hours, more preferably from 30 minutes to 6 hours. This step (d) effectively eliminates the deviation markers. It also makes it possible to limit the excessive formation of molecules of oenological interest which can be formed under the effect of temperature, especially under the prior art heating conditions described above, such as vanillin and guaiacol. In fact, too much formation of these molecules will have a negative effect on the organoleptic perception of the wines raised in the presence of these pieces of treated wood.

The pieces of wood thus treated can then be brought into contact with wine, spirits or water. The invention also relates to an oenological product consisting of the pieces of wood that can be obtained by the process as described above. In particular, this oenological product consists of pieces of wood treated by the method according to the invention, and has a markedly reduced amount of deviation markers compared to that present in the wood pieces before treatment. Preferably, the oenological product according to the invention has a remaining amount of deflection markers ranging from 0 to 25% by weight relative to the initial weight of deviation markers in unprocessed pieces of wood (ie before treatment) with the process according to the invention. This is a significant improvement over the oenological products treated with prior art processes, which have a remaining amount of deflection markers ranging from 75 to 99% by weight relative to the initial weight of deflection markers in the pieces of unprocessed wood (ie before treatment) with the method of the prior art. Another subject of the invention relates to the use of the oenological product according to the invention in combination with a must, a wine, a spirits, water, one or more solvents such as ethanol, or a mixture of water / solvent (s). For example, the oenological product, that is to say the pieces of wood that can be obtained with the process of the invention, is brought into contact with a must, or with wine on the alcoholic fermentation stage. or during aging, preferably in an amount of from 0.5 to 20 g / l, more preferably from 1 to 10 g / l of wine. The total contact time can range from 5 days up to 12 months, preferably from 10 days to 12 months.

Thus, the invention relates to a process for making musts, wines and spirits comprising contacting a must, a wine or a spirit with the pieces of wood treated with the process as described herein. -above. Another use of the oenological product is to bring into contact the pieces of wood obtainable with the process of the invention with water, one or more solvents such as ethanol, or a mixture thereof. For example, the oenological product can be macerated in water, one or more solvents such as ethanol, or a mixture thereof, then concentrated and spray-dried, lyophilized or other technique. This use leads to the manufacture of wood extracts. The dried extracts of wood can be used in various fields such as the food, pharmaceutical or cosmetic industry. In particular, in the field of oenology, dried extracts of wood are known under the name of "oenological tannin", which is used in the production of wines and spirits to facilitate the clarification of musts and wines, for example in a quantity of 0.1 to 1 g / 1 of wine or spirits. They must not change the olfactory properties and the color of the wines. In another embodiment, the oenological product is macerated in boiling water, in particular at a temperature ranging from 80 to 100 ° C., preferably in an amount ranging from 0.5 to 100 g / l, more preferably 10 to 50 g / 1 of water. The duration of maceration can range from 1 hour to 24 hours, better from 6 to 12 hours. This last use leads to the production of wooded waters. Then, the wood water obtained is mixed with or without an additional concentration, for example by evaporation or any other equivalent technique, with a wine or spirits. The invention also relates to a composition comprising in a medium, an oenological product according to the invention, said medium being a must, a wine, a spirit, water, one or more solvents such as ethanol, or a water mixture / solvent (s).

The oenological product according to the invention is preferably contained in an amount ranging from 0.5 to 100 g / l of medium. In a first embodiment, the oenological product according to the invention is contained in an amount ranging from 0.5 to 20 g / l, better still from 1 to 10 g / l of must, wine or spirits.

In a second embodiment, the oenological product according to the invention is contained in an amount ranging from 0.5 to 100 g / l better than 10 to 50 g / l of water, of one or more solvents such as ethanol, or a mixture thereof.

The subject of the invention is also a process for making musts, wines and spirits, comprising bringing into contact a must, a wine or a spirit with the pieces of wood that may be obtained with the process of the invention.

Still another object of the invention is a method of manufacturing wood extracts, such as wooded waters, comprising contacting water, one or more solvents such as ethanol, or one of mixtures thereof, with the pieces of wood obtainable with the process of the invention, and optionally a drying step such as atomization or lyophilization. The invention also relates to the method of manufacturing wooden containers such as barrels and barrels, for the breeding of wines and spirits, including the method of treating pieces of wood as described above.

The invention is illustrated by the following examples. EXAMPLES Example 1 French oak wood editions were subjected to a process according to the invention comprising: (a) a step of drying in the open air for 18 months, (b) a step of mechanical transformation consisting of grind and sift in order to obtain the pieces of wood in the form of 3 cm chips of linear dimension (ie its greatest length), and (c) a step of heating by convection of hot air for 1.5 hours at temperature 180 ° C. A step (d) of heating was carried out after the heating step (c) under CO2 in the supercritical state, at a temperature of 80 ° C, under a pressure of 46 MPa (460 bar) for 3 hours. Shavings thus treated were put in a hydroalcoholic solvent simulating wine having an ethanol content of 12.5% by volume, at room temperature (20-25 ° C.), and a pH of 3.5, in an amount of 20 g. / 1 of solvent. Maceration took place for 24 hours in the dark, with stirring of 200 rpm (orbital shaking). The solvent was then filtered and the extraction solvent analyzed by high performance liquid chromatography (or HPLC) and gas chromatography, to detect and quantify the deflection marker molecules and their precursors as well as the molecules with enological interest. . These two analysis techniques are commonly used in the field, as described, for example, in the following article: Moutounet, M., Rabier, P., Puech, JL, Verette, E., Barillere, J. "Analysis by HPLC of extractable substance in oak wood." Application to a Chardonnay ", Food Science, 1989, 9, 35-51. The same extraction was repeated on untreated chips. The extraction yields, which represent the difference between the values found in the pieces of wood before and after treatment, were then calculated. The results are shown in Table 1 below.

Table 1: Extraction yield expressed in% Compounds of interest to winemaking Trans-Whiskey-Lactone 4.0 Cis-Whiskey-Lactone 4.1 Furfural 6.5 5-Methylfurfural 5.0 Vanillin, 34 Syringaldehyde 1.8 C oni feral 0.9 dehydroxymethylfurfural dehydrate 4.6 Derivative marker compound Linoleic acid 98.7 Trans-2-nonenal 86.3 Non-significant losses of compounds with organoleptic interest and very significant elimination of compounds - deflection markers and their precursors. EXAMPLE 2 French oak wood editions were subjected to a process according to the invention, comprising: (a) a step of drying in the open air for 12 months, and (b) a step of mechanical transformation consisting in grinding and sieving to obtain the pieces of wood in the form of particles having diameters ranging from 0.5 to 1 cm.

A step (d) of specific heating was carried out after step (b) under CO2 in the supercritical state, at a temperature of 80 ° C, under a pressure of 46 MPa (460 bar) for 3 hours. Shavings thus treated were put in a hydroalcoholic solvent simulating wine having an ethanol content of 12.5% by volume, at room temperature (20-25 ° C.), and a pH of 3.5, in an amount of 20 g. / 1 of solvent. Maceration took place for 24 hours in the dark under stirring at 200 rpm (orbital shaking).

The solvent was then filtered and the extraction solvent analyzed by high performance liquid chromatography (or HPLC) and gas chromatography, to detect and quantify the deflection marker molecules and their precursors as well as the molecules with enological interest. .

The same extraction was repeated on untreated chips. The extraction yields, which represent the difference between the values found in the pieces of wood before and after treatment, were then calculated. The results are shown in Table 2 below.

Table 2: extraction yield expressed in% Compounds with an interest in oenology Trans-WhiskeyLactone 29.2 Cis-WhiskeyLactone 32.2 Derivative marker compound Linoleic acid 99.0 Trans-2-nonenal 88.9 Losses can be observed non-significant compounds with organoleptic interest and very significant elimination of compounds - deviation markers and their precursors.

Claims (16)

REVENDICATIONS1. A process for treating pieces of wood, preferably oak, comprising the following steps: (a) drying the pieces of wood, (b) mechanical transformation, and (c) optionally heating, in which a step of heating (d) under an inert atmosphere, at a temperature ranging from 30 to 120 ° C and a pressure of from 1 to 60 MPa (10 to 600 bar), this step (d) being carried out after step (a) , (goat). 2. Method according to claim 1, characterized in that the pieces of wood are selected from staves, logs and studs. 3. Method according to claim 1 or 2, characterized in that step (a) is carried out in the open air for a period ranging from 6 to 36 months and / or in an oven at a temperature ranging from 20 to 40 ° C. 4. Method according to any one of the preceding claims, characterized in that step (c) is carried out at a temperature ranging from 50 to 300 ° C, preferably from 70 to 250 ° C, for 5 minutes to 32 hours , better from 10 minutes to 24 hours, in the presence of air, under atmospheric pressure. 5. Method according to any one of the preceding claims, characterized in that the inert atmosphere in step (d) consists of carbon dioxide preferably in a dense state under pressure, better in the supercritical state. 6. Method according to any one of the preceding claims, characterized in that step (d) is for a period of 10 min. at 24 hours, better 30 min. at 6 o'clock. 7. Method according to any one of the preceding claims, characterized in that step (d) is in the presence of a co-solvent. 8. Process according to claim 7, characterized in that the co-solvent is chosen from water, ethanol and their mixtures. 9. Process according to claim 7 or 8, characterized in that the cosolvent is present in an amount ranging from 0.01% to 10% by weight, preferably from 0.02% to 1% by weight relative to the weight of the product. inert gas. 10. Method according to any one of the preceding claims, characterized in that step (d) is carried out by compression / decompression cycles. 11. Oenological product consisting of pieces of wood, obtainable by the method according to any one of the preceding claims. 12. Use of the oenological product according to claim 11, in combination with a must, a wine, a spirit, water, one or more solvents such as ethanol, or a mixture of water / solvent (s). 13. Composition comprising in a medium, an oenological product according to claim 11, preferably in an amount ranging from 0.5 to 100 g / l of medium, said medium being a must, a wine, a spirit, water , one or more solvents such as ethanol, or a water / solvent mixture (s). 14. A method of making musts, wines and spirits, comprising contacting a must, a wine or a spirit with the pieces of wood obtainable by the method according to one of the following: any of claims 1 to 10. 15. A method of manufacturing wood extracts, such as woody waters, comprising contacting water, one or more solvents such as ethanol, or a mixture thereof with the pieces of wood obtainable with the method according to any one of claims 1 to 10, and optionally a drying step. 16. A method of manufacturing wooden containers, characterized in that the wood has been previously treated with the method according to any one of claims 1 to 10.