Method for accelerating ageing of whisky

Abstract

The invention relates to a whisky aging acceleration method, which comprises: S1, preparing a Kangpu tea fermentation liquid by using coffee pericarp, fermenting for 7-15 days to form a coffee pericarp Kangpu tea fermentation liquid, the pH value of the fermentation liquid being 3.45-3.85, the acetic acid content being 4.2-5.8 g / L, and the lactic acid content being 1.5-3.2 g / L; s2, injecting the newly distilled grain whisky into a moderately baked American white oak barrel for ageing, wherein the alcoholic strength of the whisky base liquor is 63% vol, and the pH value is 6.4; and S3, adding the coffee pericarp Kangpu tea fermentation liquor prepared in the step S1 into the whisky base liquor in the step S2 in stages, adding the coffee pericarp Kangpu tea fermentation liquor into the whisky base liquor in the step S2 in a manner that the total addition amount of the coffee pericarp Kangpu tea fermentation liquor is 18.0 + / -1.2% of the volume of the whisky base liquor, and aging the whisky base liquor for 24 months until the whisky base liquor reaches the premium standard that the pH is 4.0 + / -0.15 and the total acid is greater than or equal to 0.30 g / L specified by the national standard GB / T 11856.1-2025.

Description

Technical Field

[0001] The invention belongs to the technical field of wine brewing, and in particular relates to a method for accelerating the aging of whiskey. Background Art

[0002] The aging process of whiskey is a key factor in determining its flavor quality. Traditional methods rely on long-term storage in oak barrels (typically more than five years), imparting a complex aroma and taste through the slow interaction between the wood and the spirit. However, oak barrel aging results in an average annual volatility loss rate of approximately 2%, and long-term storage leads to low raw material utilization. Furthermore, overall acidity is uncontrollable during prolonged aging: the kinetic relationship between lignin degradation and organic acid production is complex, leading to batch-to-batch pH fluctuations (±0.3), which do not meet the stability requirements for total acidity in Section 6.2 of GB / T 11856.1-2025, Physical and Chemical Requirements.

[0003] In summary, long aging periods result in high production costs and resource consumption, and are constrained by environmental factors (such as temperature, humidity, and oak barrel characteristics), making precise control of product specifications difficult. In recent years, to shorten the aging cycle, the industry has experimented with physical ripening methods (such as ultrasound and infrared treatment) or chemical additives (such as soaking in oak chips). However, these methods can easily disrupt the balance of the whisky, leading to insufficient production of flavor compounds (such as esters and phenols) and even introducing off-flavors, making it difficult to meet premium whisky standards (such as the stringent pH and total acidity requirements of the national standard GB / T 11856.1-2025).

[0004] Meanwhile, the large quantities of coffee husks produced during coffee processing are typically treated as waste, and their rich properties in polysaccharides, polyphenols, and organic acids have yet to be fully utilized. Kombucha, a fermentation product of symbiotic bacteria (SCOBY), is known to metabolize organic acids such as acetic acid and lactic acid, as well as flavor precursors, but its application in alcohol aging remains unexplored. Existing technologies lack a solution for combining coffee husk kombucha fermentation broth with whiskey aging processes, nor a precise addition strategy for dynamically controlling acidity in stages to coordinate with the volatilization patterns of oak barrels. Summary of the Invention

[0005] In order to solve the above technical problems, the purpose of the present invention is to provide a method for accelerating the aging of whiskey, which not only shortens the aging period, but also gives the whiskey a unique flavor through waste resource utilization, and has both economic and environmental value.

[0006] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions: A method for accelerating the aging of whiskey, comprising the following steps: S1, using coffee husks to prepare kombucha fermentation liquid, and fermenting it for 7-15 days to form coffee husk kombucha fermentation liquid, wherein the fermentation liquid has a pH value of 3.45-3.85, an acetic acid content of 4.2-5.8 g / L, and a lactic acid content of 1.5-3.2 g / L; S2, pouring the newly distilled grain whiskey into medium-toasted American white oak barrels for aging, at which point the whiskey base liquor has an alcohol content of 63% by volume and a pH of 6.4; S3. The coffee cascara kombucha fermentation liquid prepared in S1 is added to the whiskey base liquor in S2 in stages, with the total amount of coffee cascara kombucha fermentation liquid added being 18.0±1.2% of the volume of the whiskey base liquor. After multiple equal-interval gradient additions, the whiskey base liquor finally reaches the excellent grade standards of pH 4.0±0.15 and total acid ≥0.30 g / L specified in the national standard GB / T 11856.1-2025 after 24 months of aging.

[0007] As a preferred embodiment, in step S1, the method for preparing the coffee cascara kombucha fermentation liquid is as follows: S11. Raw material ratio: Wash the coffee husks with water, dry them at 60°C, and then mix the dried coffee husks, sucrose, and sterile water in a mass ratio of 1:10:100 to form a mixed solution; S12. Sterilization: Heat the mixture formed in S11 to 90-100°C and maintain for 10-15 minutes. Cool it to 25-30°C and transfer it to a sterilized fermentation tank to form a fermentation liquid. The total number of residual colonies in the tank should be ≤100 CFU / mL. S13. Inoculation: Inoculate 5%-10% of the total volume of the fermentation liquid with the Kombucha mother liquor and add a 3-5 mm thick biofilm (SCOBY). After inoculation, control the dissolved oxygen level at 2.5-3.5 mg / L to form the fermentation base. S14. The fermentation base material in step S13 is subjected to a two-stage fermentation to obtain coffee cascara kombucha fermentation liquid.

[0008] As a preferred embodiment, in step S14, the specific steps of the two-stage fermentation are as follows: The first stage: the fermentation base is statically cultured at a temperature of 28±1°C for 7 days; the second stage: the temperature is adjusted to 32±1°C and the dynamic culture is continued for 8 days at a stirring speed of 120-150 rpm.

[0009] As a preferred embodiment, the pH value of the fermentation base material is reduced to 3.85±0.10 after the first stage of fermentation; and the pH value of the fermentation base material is reduced to 3.45±0.05 after the second stage of fermentation.

[0010] As a preferred embodiment, in step S3, the timing of adding the coffee cask kombucha fermentation liquid in a gradient manner at equal intervals is synchronized with the volatilization cycle of the oak barrel, and the amount of each addition is positively correlated with the volatilization loss of the oak barrel, and 150-180% of the volatilization loss in each 4-month cycle is compensated.

[0011] As a preferred solution, in step S3, coffee cascara kombucha fermentation liquid is added in a gradient at equal intervals for 6 times. The specific operation steps are as follows: The first addition is at month 4: 3.0% v / v of coffee cascara kombucha fermentation liquid that has been fermented for 7 days is injected; The second addition time is in the 8th month: 3.0% v / v of coffee peel kombucha fermentation liquid that has been fermented for 15 days is injected; The third addition was at month 12: 3.0% v / v of coffee cascara kombucha fermentation liquid that had been fermented for 15 days was injected; The fourth addition was at month 16: 3.0% v / v of coffee cascara kombucha fermentation liquid that had been fermented for 15 days was injected; The fifth addition was at month 20: 3.0% v / v of coffee cascara kombucha fermentation liquid that had been fermented for 15 days was injected; The sixth addition was at month 24: 3.0% v / v of coffee peel kombucha fermentation liquid that had been fermented for 15 days was injected.

[0012] As a preferred embodiment, after the whiskey base liquor is aged for 24 months, the ethyl acetate content in the final product is ≥32 mg / 100 mL, and the phenylethanol content is ≥2.8 mg / 100 mL.

[0013] Compared with the prior art, the present invention has the following beneficial effects: This innovative method leverages the targeted fermentation properties of coffee cascara kombucha fermentation broth, adding it to a whiskey base in a phased gradient. Through a two-stage fermentation process, the organic acid composition is manipulated (acetic acid 4.2-5.8 g / L, lactic acid 1.5-3.2 g / L). Combined with the volatile compensatory mechanism of oak barrels, the pH is reduced from 6.4 to 4.0 ± 0.15 within 24 months, achieving a total acidity of ≥ 0.30 g / L. This method also significantly increases the content of key flavor compounds such as ethyl acetate (≥ 32 mg / 100 mL) and phenylethanol (≥ 2.8 mg / 100 mL). This method not only shortens the aging cycle but also, by utilizing waste resources, imparts a unique flavor to the whiskey, achieving both economic and environmental benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The drawings in the specification, which constitute a part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute a limitation on this application.

[0015] Figure 1 This is a graph showing changes in pH value of whiskey after adding coffee cascara kombucha fermentation liquid to the aging process of the present invention. DETAILED DESCRIPTION

[0016] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0017] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0018] In addition, in the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0019] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more, unless otherwise explicitly specified.

[0020] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0021] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments: A method for accelerating the aging of whiskey, comprising preparing coffee cascara kombucha fermentation liquid and accelerating the aging of whiskey, the specific steps being as follows: Step 1: Preparation of Coffee Caduceus Kombucha Fermentation Liquid 1.1 Raw material processing Take 10 kg of coffee peels, rinse with clean water to remove impurities, and dry in a 60°C oven until the moisture content is ≤8%; Weigh 1 kg of dried coffee husks, 10 kg of sucrose, and 100 kg of sterile water in a mass ratio of 1:10:100 and mix to form a fermentation mixture. The sugar-water mixture must comply with the hygienic standard for edible sugar, GB 13104-2014.

[0023] 1.2 Sterilization and inoculation The mixed solution was heated to 95°C and maintained for 12 minutes, then cooled to 28°C and transferred to a sterilized fermentation tank. The total colony count in the tank was detected to be ≤80 CFU / mL (detection method refers to GB 4789.2-2022).

[0024] Kombucha mother liquor (8% of the total volume) and a 4 mm thick biofilm (SCOBY) were added to the fermentation tank, and the dissolved oxygen was adjusted to 3.0 mg / L to form the fermentation base.

[0025] 1.3. Two-stage fermentation The first stage of static culture: the fermentation base was placed in a constant temperature environment of 28°C for 7 days, the pH value dropped to 3.82 (±0.05), and the lactic acid content reached 1.8 g / L.

[0026] The second stage of dynamic culture: the temperature was adjusted to 32°C and the fermentation was carried out at a stirring speed of 135 rpm for 8 days. The pH value further dropped to 3.46 (±0.03), the acetic acid content reached 5.2 g / L, and the lactic acid content increased to 2.7 g / L.

[0027] The final coffee cascara kombucha fermentation liquid was obtained with a pH of 3.48 and a total acid content of 7.9 g / L (acetic acid 5.2 g / L + lactic acid 2.7 g / L).

[0028] Step 2: Initial aging of whiskey base liquor Newly distilled grain whisky (initial alcohol content 63% vol, pH = 6.4) was poured into medium-toasted American white oak barrels (capacity 200 L) and sealed in a constant temperature cellar (temperature 15℃±2℃, humidity 70%±5%).

[0029] Step 3: Add fermentation broth in a phased gradient Dosing strategy: Compensate for 160% of the volatile loss every four months by adding fermentation liquid in six equal doses, with a total addition amount of 18.0% (±1.2%) of the volume of the whiskey base liquor.

[0030] Specific operations: Month 4: 6.0 L (3.0% v / v) of 7-day fermented coffee cascara kombucha fermentation liquid was injected; Months 8, 12, 16, 20, and 24: 6.0 L (3.0% v / v) of coffee cascara kombucha fermentation liquid, which had been fermented for 15 days, was injected.

[0031] Step 4: Aging endpoint detection Physical and chemical indicators: After aging for 24 months, the pH of the whiskey liquor is 4.02, and the total acid content is 0.35g / L, which meets the national standard GB / T11856.1-2025 excellent standard (such as Figure 1 shown).

[0032] Flavor substances: Ethyl acetate content is 35 mg / 100mL, and phenylethanol content is 3.0 mg / 100mL, which are significantly higher than the standard requirements (≥32 mg / 100mL, ≥2.8 mg / 100mL).

[0033] Sensory characteristics: The wine is amber in color, with prominent aromas of vanilla, caramel and citrus brought by peel fermentation. The taste is round, the acidity is balanced, and the wood flavor and fermentation acid aroma are harmoniously integrated.

[0034] Comparative example: Traditional oak barrel aging (no fermentation liquid added) The same initial whiskey base liquor was aged in the same oak barrel for 24 months and tested: pH = 5.2, total acid 0.18 g / L, ethyl acetate 22 mg / 100mL, phenylethanol 1.5 mg / 100mL, which did not meet the excellent grade standard.

[0035] Effect verification In this example, the aging period was shortened to 24 months by the gradient addition of coffee cascara kombucha fermentation liquid, and the total acid and flavor ester content were significantly increased, demonstrating that this method can accelerate the dissolution of wood components and the conversion of acid esters, while imparting a unique flavor to the liquor.

[0036] The method of the present invention causes the methylxanthines in the coffee peel to react with the degradation products of whiskey lignin to undergo a Maillard reaction, thereby promoting the ethyl acetate content to exceed 32 mg / 100 mL (national standard superior grade ≥25 mg / 100 mL), forming a triple flavor matrix of "coffee-oak-ester aroma".

[0037] The method of the present invention is applicable to categories such as grain whiskey and rye whiskey. The proportion of fermentation liquid added can be adjusted to 15% to 20% v / v according to the type of oak barrel (such as bourbon barrel and sherry barrel), realizing customized production of flavor.

[0038] This invention innovatively utilizes two-stage fermentation of coffee cascara kombucha as a pH regulator: a combined process of 7 days of static incubation at 28°C followed by 8 days of shaking incubation at 32°C yields a fermentation broth containing 4.2-5.8 g / L acetic acid and 1.5-3.2 g / L lactic acid (pH 3.45-3.85). During the whiskey aging process, six gradient additions are made every four months, with each addition amounting to 3.0±0.2% of the base beer volume (total addition amount 18.0±1.2%). This achieves a dynamic balance between targeted organic acid compensation and volatile losses, achieving an organic acid replenishment accuracy of ±0.05 pH / batch, significantly superior to the ±0.3 pH fluctuation observed with natural aging.

[0039] After 24 months of aging, the pH stabilized to 4.0±0.10 (with a narrowed fluctuation range), and the total acidity reached 2.3±0.2 g / L, achieving the breakthrough acidification index specified in GB / T 11856.1-2025. This method also promotes the synergistic effect of flavor compounds, with coffee peel polyphenols and whiskey esters forming a complex aroma system, increasing the vanillin and eugenol contents by 15-22%, meeting the aroma characteristics required for grain whiskey. Furthermore, the method improves raw material utilization to 42% and reduces the average annual volatility loss rate to 0.9%. This method complies with the requirements of GB / T 11856.1-2025, Section 5.4, regarding the aging cycle of grain whiskey, providing a controllable and efficient aging solution for industrial production.

[0040] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0041] Although the embodiments of the present invention have been shown and described above, it is understood that the above embodiments are illustrative and cannot be understood as limiting the present invention. Those skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for accelerating the aging of whiskey, characterized in that: The following steps are involved: S1, using coffee husks to prepare kombucha fermentation liquid, and fermenting it for 7-15 days to form coffee husk kombucha fermentation liquid, wherein the fermentation liquid has a pH value of 3.45-3.85, an acetic acid content of 4.2-5.8 g / L, and a lactic acid content of 1.5-3.2 g / L; S2, pouring the newly distilled grain whiskey into medium-toasted American white oak barrels for aging, at which point the whiskey base liquor has an alcohol content of 63% by volume and a pH of 6.4; S3. The coffee cascara kombucha fermentation liquid prepared in S1 is added to the whiskey base liquor in S2 in stages, with the total amount of coffee cascara kombucha fermentation liquid added being 18.0±1.2% of the volume of the whiskey base liquor. After multiple equal-interval gradient additions, the whiskey base liquor finally reaches the excellent grade standards of pH 4.0±0.15 and total acid ≥0.30 g / L specified in the national standard GB / T 11856.1-2025 after 24 months of aging.

2. The method for accelerating the aging of whiskey according to claim 1, characterized in that: In step S1, the method for preparing the coffee cascara kombucha fermentation liquid is as follows: S11. Raw material ratio: Wash the coffee husks with water, dry them at 60°C, and then mix the dried coffee husks, sucrose, and sterile water in a mass ratio of 1:10:100 to form a mixed solution; S12. Sterilization: Heat the mixture formed in S11 to 90-100°C and maintain for 10-15 minutes. Cool it to 25-30°C and transfer it to a sterilized fermentation tank to form a fermentation liquid. The total number of residual colonies in the tank should be ≤100 CFU / mL. S13. Inoculation: Inoculate 5%-10% of the total volume of the fermentation liquid with the Kombucha mother liquor and add a 3-5 mm thick biofilm (SCOBY). After inoculation, control the dissolved oxygen level at 2.5-3.5 mg / L to form the fermentation base. S14. The fermentation base material in step S13 is subjected to a two-stage fermentation to obtain coffee cascara kombucha fermentation liquid.

3. The method for accelerating the aging of whiskey according to claim 2, characterized in that: In step S14, the specific steps of the two-stage fermentation are as follows: The first stage: the fermentation base is statically cultured at a temperature of 28±1°C for 7 days; the second stage: the temperature is adjusted to 32±1°C and the dynamic culture is continued for 8 days at a stirring speed of 120-150 rpm.

4. The method for accelerating the aging of whiskey according to claim 3, characterized in that: After the first stage of fermentation, the pH value of the fermentation base material dropped to 3.85±0.10; after the second stage of fermentation, the pH value of the fermentation base material dropped to 3.45±0.

05.

5. The method for accelerating the aging of whiskey according to claim 1, characterized in that: In step S3, the timing of adding the coffee cask kombucha fermentation liquid in a gradient manner at equal intervals is synchronized with the volatilization cycle of the oak barrel. The amount added each time is positively correlated with the volatilization loss of the oak barrel, and 150-180% of the volatilization loss in each 4-month cycle is compensated.

6. The method for accelerating whiskey aging according to claim 5, characterized in that: In step S3, coffee cascara kombucha fermentation liquid is added in a gradient manner at equal intervals for 6 times. The specific operation steps are as follows: The first addition is at month 4: 3.0% v / v of coffee cascara kombucha fermentation liquid that has been fermented for 7 days is injected; The second addition time is in the 8th month: 3.0% v / v of coffee peel kombucha fermentation liquid that has been fermented for 15 days is injected; The third addition was at month 12: 3.0% v / v of coffee cascara kombucha fermentation liquid that had been fermented for 15 days was injected; The fourth addition was at month 16: 3.0% v / v of coffee cascara kombucha fermentation liquid that had been fermented for 15 days was injected; The fifth addition was at month 20: 3.0% v / v of coffee cascara kombucha fermentation liquid that had been fermented for 15 days was injected; The sixth addition was at month 24: 3.0% v / v of coffee peel kombucha fermentation liquid that had been fermented for 15 days was injected.

7. The method for accelerating whiskey aging according to claim 1, wherein: After the whiskey base liquor is aged for 24 months, the ethyl acetate content in the final product is ≥32 mg / 100 mL, and the phenylethanol content is ≥2.8 mg / 100 mL.

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