MD1719Z - Process for treating oak wood used in the maturation of strong drinks - Google Patents

Abstract

The invention relates to the alcohol industry, namely to a process for treating oak wood used in the maturation of strong drinks.The process, according to the invention, comprises shredding of thermally treated oak wood, packaging thereof, introduction into the shredded wood of softened water or raw distillate, or aged distillate, or mixtures thereof, into which hydrogen peroxide and, optionally, ammonia water have been previously added, sealing-in of the package and subsequent aging of oak wood until at least complete decomposition of hydrogen peroxide.

Description

The invention relates to the alcohol industry, namely to a process for treating oak wood used in the maturation of spirits.

The process of using oak wood as staves (for barrels or placed in large hermetic vessels), in the presence of which distillates used in the manufacture of aged spirits are preserved and aged for a long time [1].

The disadvantages of the process are the increased requirements for the quality of the raw material, the long duration of preliminary drying-preservation of the wood, the inefficient use of expensive oak wood, the unstable quality of the product obtained, the slow speed of the processes and the long aging time of the distillates, which led to the development of oak wood activation processes.

The process of accelerating the maturation of alcoholic distillate is known, which involves activating oak wood by prior hydrolysis of oak wood with weak base or acid solutions (1%) at a temperature of 25°C within 24 hours [2].

The process, despite its wide spread in practice, due to the partial elimination of substances with a bitter taste and a smell of "raw" wood, has as its main drawback its unidirectionality (slight hydrolysis of substances only in the layers on the outer surface of the wood - the staves, primarily of polysaccharides), which does not allow for the rational use of the total potential of the wood. Moreover, the process does not involve a deeper activation, including by transforming the complex of tannins and lignin of the wood, which plays a primary role in the quality of aged spirits.

The process of manufacturing an accelerator used in the production of aged spirits is also known, which involves chopping and moistening oak wood, followed by maceration in two stages at a relative humidity of 80-85%. The first stage, carried out at a temperature of 35-40°C, 40 hours, aims to oxidize tanning substances, and the second, carried out at a temperature of 50°C, 40 - 50 hours, aims to hydrolyze fats with the formation of glycerin, ketones, acids. After this, the chopped oak wood is dried by raising the temperature to 115°C [3].

The mentioned process, although described in detail and simple to implement, has not gained widespread use in winemaking, probably as a result of the lack of a predictable and constant effect.

In oenological practice, the use of wood thermally treated at high temperatures (torrification, from French - torrefié, roasting) for the purpose of maturation (aging) or immediate improvement of the qualities of beverages is known [4].

The positive effect of heat treatment at high temperatures is explained by the fact that some of the wood substances are transformed (thermodegraded), acquiring specific organoleptic qualities and increased solubility.

The process of accelerating the maturation of alcoholic distillate is known, which includes preliminary washing of oak wood with cold and warm water, drying it to a humidity of 10-12%, followed by its thermal treatment at a temperature of 115-140°C for 3-7 days with access to a heated air stream [5].

The described process is widely used in practice due to its positive effects, including the possibility of reducing the aging terms of aged spirits and improving their organoleptic properties.

At the same time, the duration of the aging process of hard drinks using activated oak wood according to the described procedure remains quite long, which is explained by the complexity of the processes that take place with the participation of oak wood substances during maturation-aging (primarily their solubilization and oxidation).

In this regard, the described process has room for improvement by carrying out prior processes that lead to transformations of oak wood substances, characteristic of those that occur during the long aging of strong drinks.

The process of accelerated production of an aged strong drink using activated (specially treated) oak wood extraction is known, which may serve as the closest solution [6].

The process includes treating-activating oak wood in the following stages:

- light hydrolysis of hemicellulose in shredded oak wood, moistened with 0.5% hydrochloric acid solution, in a ratio of 1:0.6, at a temperature of 100-105°C, within 30 min;

- oxidation of tanning substances with oxygen from the air under high pH conditions, after wetting the shredded wood with a 1-2% ammonia solution, in a ratio of 1:0.6, within 10 min;

- destruction of lignin in oak wood and oxidation of decomposition products at high temperatures of 160-170°C and the action of air oxygen (thermolysis) within 60 min.

Despite the fact that the process would largely allow the activation of oak wood by modeling the processes that occur with its substances during the aging of hard drinks, it remained at the stage of laboratory and semi-industrial tests, without gaining application at the industrial level.

The main drawback of the process is the regimes, which are determined in the laboratory and are practically impossible to repeat under production conditions (high temperatures, strictly determined duration), which leads to unpredictable results. Moreover, the process requires specific and quite sophisticated technological equipment, which can lead to increased product costs.

The problem solved by the alleged invention consists in simplifying the process of activating oak wood intended for use in the manufacture of aged spirits as well as in reducing production costs while improving the quality of the finished product.

The oak wood treatment process used in the maturation of hard drinks, according to the invention, includes shredding the heat-treated oak wood, packaging it, administering to the shredded wood softened water or raw distillate, or aged distillate, or a mixture thereof, in an amount of 1.0-2.0 dm3/kg, to which hydrogen peroxide has previously been added in an amount of 5.0-0.10 g/dm3 (in atomic oxygen), sealing the packaging and subsequently maintaining the oak wood at least until the hydrogen peroxide has completely decomposed.

At the same time, in the softened water or the raw alcoholic distillate, or the aged distillate, or their mixture with the addition of hydrogen peroxide, ammonia water is additionally added in an amount of 2.5-5.0 g/dm3 (in ammonia).

The invention solves the problem in that the proposed process provides for the acquisition and shredding of oak wood, wet hydrolysis, oxidation in the presence of oxygen and its thermolysis at high temperatures. The crushed thermally treated (thermolized) oak wood is sent to wet hydrolysis, after soaking with blending components of future strong drinks in an amount of 1.0-2.0 dm3/kg, while the hydrolysis is carried out in closed containers or packages, simultaneously with the oxidation of the products of thermolysis and hydrolysis of wood components, in the presence of atomic oxygen.

As blending components of future spirits, as a rule, softened water or raw or aged distillate, or a mixture thereof, are used, while hydrolysis and oxidation of the components of the crushed thermolyzed wood is carried out during its transportation and/or storage. Hydrolysis and oxidation of the components of the crushed thermolyzed wood is preferably carried out in a basic environment and in the presence of atomic oxygen, created by ammonia water and hydrogen peroxide, introduced into the blending components in quantities of 2.5-5.0 g/dm3 (in ammonia) and 5.0-10.0 g/dm3 (in atomic oxygen), respectively.

The proposed invention differs from the previous solution in that it provides:

- previously thermolyzed (heat-treated at high temperatures) chopped oak wood is sent to wet hydrolysis;

- the chopped oak wood is moistened by soaking in it the blending components of the future strong drinks in an amount of 1.0-2.0 dm3 per 1 kg;

- wet hydrolysis is carried out simultaneously with the oxidation of the products of thermolysis and hydrolysis of wood components in the presence of atomic oxygen;

- hydrolysis and oxidation of the components of the shredded thermolyzed wood is carried out in closed containers or packaging;

- the oxidation of the products of thermolysis and hydrolysis of oak wood components is carried out under the action of atomic oxygen;

- hydrolysis and oxidation of the components of the chopped thermolyzed wood in the presence of atomic oxygen is carried out in a basic environment;

- the basic environment and activated oxygen are created by the ammonia water and hydrogen peroxide introduced;

- ammonia water and hydrogen peroxide are introduced into the blending components in quantities of 2.5-5.0 g/dm3 (in ammonia) and, respectively, 5.0-10.0 g/dm3 (in activated oxygen);

- softened water or raw or aged distillate or a mixture thereof are used as blending components of future strong drinks;

- hydrolysis and oxidation of the components of the chopped thermolyzed wood is carried out during its transportation and/or storage.

The technical result and the positive effect of the invention, namely, the simplification of the oak wood treatment process intended for use in the manufacture of aged spirits, activating it, as well as the reduction of production costs with the improvement of the quality of the finished product, is due to the fact that the proposed process allows the use of standard equipment, containers and packaging, with the division of short-term processes (thermal treatment - thermolysis, carried out in advance) and long-term processes (hydrolysis and oxidation, carried out simultaneously).

Moreover, the hydrolysis and oxidation of oak wood components is carried out in the liquid environment inside the pores of thermolyzed oak wood, in closed containers or packages (which exclude or reduce losses, ensuring the preservation of the reactive environment), under the action of atomic oxygen (which has increased reactivity in a wide range of temperatures, including the temperatures of storage and/or transportation of shredded oak wood).

Carrying out reactions, primarily oxidation, of the components of the chopped thermolyzed wood in the basic environment ensures preferential conditions for oxidative transformation of tannins and lignin thermolysis products, with the formation of a complex of components, which positively influences the quality of aged spirits.

The quantities of ammonia water and hydrogen peroxide, introduced into the blending components - respectively 2.5-5.0 g/dm3 (in ammonia) and 5.0-10.0 g/dm3 (in atomic oxygen), ensure optimal conditions for the mentioned processes.

The use of softened water or raw or aged distillate, or a mixture thereof, allows the direct introduction of wet activated oak wood into distillates or hard drinks, which simplifies the process and reduces production costs.

Performing the hydrolysis and oxidation of the components of the moistened, shredded thermolyzed wood during its transportation and/or storage (in closed containers or packages) allows for the rational use of both space (containers or packages, including production) and time (duration of transportation and storage) to carry out the oak wood activation process.

The final summary result obtained from applying the proposed procedure and the combination of characteristics that distinguish it are directly related.

To carry out this process, oak wood, used in the practice of making aged spirits, is required, as well as standard heat treatment and grinding equipment, containers or packaging, including for making and/or storing, and/or transporting, and blending components for spirits.

The proposed procedure is carried out in the following way.

Oak logs, collected from forests by cutting down trees at least 80 years old during the cold season, are sent to forestry enterprises for preliminary storage for several months, after which they are transformed into planks, staves, laths, etc., which serve as raw material from oak wood, used for activation (and use in aging hard drinks) according to the proposed process.

The raw material made of oak wood is previously subjected to heat treatment (torching) in the presence of hot air, for example according to the regimes described in source [5] (at a temperature of 115-140°C, within 3-7 days).

Heat-treated oak wood is shredded and, as a rule, sieved into fractions, which are sent for storage or directly for packaging in the production packaging.

The chopped heat-treated oak wood, placed in closed storage containers (plastic barrels, etc.) or in closed production packaging (polyethylene bags, metalized plastic bags, etc.), is moistened with blending components of future spirits, separately or in a mixture (raw or aged distillate, spirit blend, softened water), in an amount of 1.0-2.0 dm3 per 1 kg, fully soaked in the wood (without free liquid).

In the blend components intended to be introduced into oak wood, it is preferable to add ammonia water and/or hydrogen peroxide in quantities of 2.5-5.0 g/dm3 (in ammonia) and 5.0-10.0 g/dm3 (in atomic oxygen), respectively.

The crushed and moistened heat-treated oak wood is kept for hydrolysis and oxidation of the components for a period that is not strictly determined, but, as a rule, 2-4 months are sufficient for ordinary temperatures of 15-20°C. At temperatures higher than 25°C, the duration of the process can be reduced to 10-15 days, however, the period must not be less than the time required for the complete decomposition of hydrogen peroxide from the blend components soaked in the wood.

After the minimum activation period has expired, oak wood can be stored in airtight containers and packaging, without major changes, for at least 12 months.

The maintenance of the crushed and moistened heat-treated oak wood is carried out in closed storage containers or in closed production packages during their storage-storage or transportation to the producers of hard drinks, where the activated oak wood is used directly in production (in the manufacture of hard drinks) or, for the same purpose, after additional storage-storage.

Activated shredded oak wood is introduced wet into distillates, which are enriched with oak extractive substances, including being preserved and aged, according to accepted practices at enterprises.

Distillates enriched with oak extractive substances, upon reaching the necessary technological indicators, are removed from aging and directed to blending with softened water, sugar syrup and caramel (if necessary) to obtain aged spirits.

Conditioned aged spirits undergo additional treatments and are directed to bottling and production.

The proposed process is illustrated by laboratory and semi-industrial application examples.

Example 1

The oak staves, intended for use in aging distillates for the purpose of producing aged spirits, were rinsed with cold and hot water, dried in a heated room, and then heat-treated at 125°C for 5 days in a hot air stream.

The wood of the heat-treated (torified) staves, as a result of the partial thermal degradation of lignins and other components, acquired a light brown color and a pleasant vanilla-spicy smell.

The heat-treated staves were subjected to shredding, and the resulting oak chips were distributed in hermetically sealed packaging - self-adhesive polyethylene bags with a capacity of 100 g each.

In the bags with crushed heat-treated oak sawdust, before sealing them, softened water was introduced in a volume of 200 cm3 each, to which hydrogen peroxide was previously added at a rate of 5.0 g/dm3 (in atomic oxygen).

The sealed bags were stored under normal conditions, and after 2, 6 and 12 months, one after the other, they were opened, and the wet sawdust (activated oak wood) was subjected to technological testing, the data of which are presented in Table 1.

Table 1

Physico-chemical indices (determined in 65%vol alcoholic solution, after extraction, 10g*/dm3, 50°C, 5 hours) Activated shredded oak wood according to the known solution [6] according to the known solution [5] according to the proposed procedure, after storage initial approximate solution 2 months 6 months 12 months Optical density of the alcoholic extract 0.32 0.28 0.29 0.31 0.32 Concentration of the solubilized extract, g/dm3, -including reducing substances, g/dm3 0.74 0.15 0.68 0.10 0.79 0.17 0.89 0.22 0.95 0.25 Concentration of solubilized tannins, g/dm3 0.35 0.32 0.38 0.42 0.44 Concentration of substances Total phenolics, g/dm3 0.41 0.38 0.42 0.45 0.48 Aromatic aldehydes concentration, mg/dm3 5.20 3.90 5.80 6.70 7.10

*- calculated on the weight of dry wood

Example 2

The oak staves, intended for use in aging distillates for the purpose of making aged spirits, were rinsed with cold and hot water, dried in a heated room, and then heat-treated at 140°C for 3 days in a hot air stream.

The wood of the heat-treated (torified) staves, as a result of the partial thermal degradation of lignins and other components, acquired a dark brown color and a pleasant scent of spiced coffee.

The heat-treated staves were subjected to shredding, and the resulting oak chips were distributed in hermetically sealed packaging - metallized polyethylene bags with a capacity of 1 kg each.

In the bags with crushed heat-treated oak shavings, before sealing them, a mixture of aged wine distillate and softened water with a strength of 40% vol. was introduced, in a volume of 150 cm3 each, to which hydrogen peroxide was previously added at a rate of 8.0 g/dm3 (in atomic oxygen) and ammonia water at a rate of 2.5 g/dm3 (in ammonia).

After sealing, the sealed bags were kept under normal laboratory conditions, and after 2, 6 and 12 months, one after the other, they were opened, the wet sawdust in them (activated oak wood) being subjected to technological testing, the data of which are presented in Table 2.

Table 2

Physico-chemical indices (determined in 65%vol alcoholic solution, after extraction, 10g*/dm3, 50°C, 5 hours) Activated shredded oak wood according to the known solution [6] according to the known solution [5] according to the proposed procedure, after storage initial approximate solution 2 months 6 months 12 months Optical density of the alcoholic extract 0.32 0.28 0.42 0.51 0.54 Concentration of the solubilized extract, g/dm3, -including reducing substances, g/dm3 0.74 0.15 0.68 0.10 0.83 0.19 0.90 0.20 0.93 0.22 Concentration of solubilized tannins, g/dm3 0.35 0.32 0.41 0.47 0.49 Concentration of phenolic substances total, g/dm3 0.41 0.38 0.44 0.48 0.51 Aromatic aldehydes concentration, mg/dm3 5.20 3.90 6.70 7.80 8.20

*- calculated on the weight of dry wood

Example 3

Commercial oak chips (shredded oak wood) with enhanced heat treatment (Forte), received at the enterprise in hermetically sealed packaging of 10 kg, for the purpose of using it in the manufacture of hard drinks, were directed to activation according to the proposed process.

In the chopped and heat-treated oak wood of each packaging unit, opened with caution, raw wine distillate was introduced in a volume of 10 dm3, to which hydrogen peroxide was previously added at a rate of 10.0 g/dm3 (in atomic oxygen) and ammonia water at a rate of 5.0 g/dm3 (in ammonia).

The packaging units with the moistened oak wood were carefully sealed and stored under normal production conditions, and after 4 months they were transported to the production hall where they were additionally stored for approximately 2 months. The moistened oak chips (activated oak wood), upon opening the packaging, were taken for technological testing, the data of which are presented in Table 3, after it was used in the manufacture of hard drinks according to the practices of the enterprise.

Table 3

Physico-chemical indices (determined in 65%vol alcoholic solution, after extraction, 10g*/dm3, 50°C, 5 hours Industrially thermally activated shredded oak wood (Forte), control according to the proposed procedure, after storage Initially approximately 6 months Optical density of alcoholic extract 0.38 0.51 Concentration of solubilized extract, g/dm3, -including reducing substances, g/dm3 0.65 0.11 0.86 0.25 Concentration of solubilized tannins, g/dm3 0.32 0.43 Concentration of total phenolic substances, g/dm3 0.43 0.56 Concentration of aromatic aldehydes, mg/dm3 3.7 9.5

*- calculated on the weight of dry wood

The description of the execution of the proposed process in examples 1, 2 and 3, as well as the results of the physico-chemical testing of the shredded oak wood, activated according to known processes and according to the proposed process, presented in tables 1, 2 and 3, allow us to conclude that the invention solves the technical problem.

The proposed process is simple to implement and requires minimal additional costs. It is performed in hermetic containers or packaging, including standard ones, mainly during the storage-transportation-storage of chopped oak wood, which does not require additional equipment, space or time, nor temperature regulation along the way (it takes place at normal temperatures).

At the same time, the proposed process allows the activation of chopped oak wood with an increase in the quantities of practically all soluble extractive substances. Moreover, the oak wood activated by this process contains more aromatic substances (aromatic aldehydes), which positively affects the organoleptic properties of future spirits.

Alcoholic extracts of oak wood, activated according to the proposed process, compared to alcoholic extracts of oak wood, activated according to known processes, contain not only more extractive substances, but also possess more complex and intense aromas - vanilla, spicy, balsamic, and their taste is full, long, moderately astringent-sweet, with notes of noble oak.

1. Nyagu И. Cognac and calvados production in Moldova. Chişinău, Картя Мольдовеняске, 1978, р. 81-84

2. SU 118026 A1 1958.00.00

3. SU 255166 A1 1970.04.28

4. FR 342123 A 1904.08.31

5. SU 122122 A1 1959.00.00

6. SU 130023 A1 1960.00.00

Claims (2)

1. Process for treating oak wood used in the maturation of hard drinks, which includes shredding heat-treated oak wood, packaging it, administering to the shredded wood softened water or raw distillate, or aged distillate, or a mixture thereof, in an amount of 1.0-2.0 dm3/kg, to which hydrogen peroxide has previously been added in an amount of 5.0-0.10 g/dm3 (in atomic oxygen), sealing the packaging and subsequently maintaining the oak wood at least until the hydrogen peroxide has completely decomposed. 2. Process according to claim 1, wherein ammonia water is additionally added in an amount of 2.5-5.0 g/dm3 (in ammonia) to the softened water or the raw alcoholic distillate, or the aged distillate, or their mixture with the addition of hydrogen peroxide.