METHOD FOR MANUFACTURING RAPIDLY AGED SPIRITS

Abstract

A method for producing a rapidly aged spirit is provided that blends a young spirit with an aged spirit and accelerates the formation of flavor compounds through the addition of heat and oxygen in the presence of wood adjuncts over time. Chemical analysis of selected flavor compounds informs the termination of the aging process and can produce a rapidly aged spirit that presents the flavor characteristics and flavor compounds of a mature barrel aged spirit in significantly less time. Contribution of flavor compounds from barrel aged spirits compliments the oxidation of flavor compounds to more complex or long chain molecules.

Claims

1. A method of producing a rapidly aged spirit comprising the steps of: providing a first spirit liquid; providing a second spirit liquid; providing a third spirit liquid; combining said first spirit liquid, said second spirit liquid, and said third spirit liquid to provide an untreated blended spirit; placing said untreated blended spirit into a reaction vessel; determining the concentration of a first flavor compound in said untreated blended spirit; adding a wood adjunct to said reaction vessel; adding oxygen and heat to said reaction vessel to produce an in-treatment blended spirit; determining the concentration of said first flavor compound in said in-treatment blended spirit over time; and terminating the addition of oxygen and heat when the concentration of said first flavor compound in said in-treatment blended spirit is twice the concentration of said first flavor compound in said untreated blended spirit to produce a treated spirit.

2. The method of claim 1 wherein: said first flavor compound is trans-β-Ionone.

3. The method of claim 1 wherein: said first spirit liquid is a barrel aged bourbon aged for at least two years; said second spirit liquid is a barrel aged bourbon aged at least three years; said third spirit liquid is a barrel aged bourbon aged at least twelve years; and said first flavor compound it cis-Whiskey lactone.

4. The method of claim 1 further comprising the steps of: determining the concentration of a second flavor compound in said untreated blended spirit; determining the concentration of said second flavor compound in said in-treatment blended spirit over time; and said terminating step is executed when said second flavor compound in said in-treatment blended spirit is at least three times the concentration of said second flavor compound in said untreated blended spirit.

5. The method of claim 1 further comprising the steps of: determining the concentration of 5-methyl-2-Furancarboxaldehyde in said untreated blended spirit; determining the concentration of 5-methyl-2-Furancarboxaldehyde in said in-treatment blended spirit over time; and said terminating step is executed when said 5-methyl-2-Furancarboxaldehyde concentration in said in-treatment blended spirit is at least five times said concentration of 5-methyl-2-Furancarboxaldehyde in said untreated blended spirit.

6. The method of claim 1 further comprising the steps of: determining the concentration of vanillin in said untreated blended spirit; determining the concentration of vanillin in said in-treatment blended spirit over time; and said terminating step is executed when said vanillin in said in-treatment blended spirit is at least 50% greater than said concentration of vanillin in said untreated blended spirit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0012] The process of esterification is one of the most critical reactions for flavor maturation. In general, the shorter chain carboxylic acids have a sour or tart flavor, which turns increasingly waxy as the molecular weight of the compound increases. In the presence of ethanol and an acid, such as acetic acid, a process of esterification occurs slowly, converting the carboxylic acids into ethyl esters. The flavors of ethyl esters containing compounds vary greatly, but common flavors include sweet, fruity, and floral. One example observed in a spirit aging process is the conversion of succinic acid, which tastes very tart, to diethyl succinate, which has an apple-like flavor. This process is accelerated by the addition of heat and oxygen, leading to the desired levels of diethyl succinate in approximately 7 weeks.

[0013] Other products currently available in the market using rapid aging techniques exist but fail to produce a product with characteristics consistent with a premium spirit. Benchmark concentrations of desired flavor compounds are presented below. Desirable ranges are presented as minimum and maximum benchmark concentrations and were determined by analysis of premium benchmark spirits. Market available spirits were analyzed to determine the concentration of these desired flavor compounds. Market Spirit 1 is manufactured with the use of light and heat to provide rapid aging. Market Spirit 2 is manufactured with the use of pressure and heat to provide rapid aging. Several benchmark compounds are not present in the rapid aged Market Spirits, shown as “non-detect” (ND), which results in flavors that are inconsistent with the premium benchmark spirits. Seven traditionally aged exemplary spirit products were selected through sensory analysis based on their representation of the desired flavor and aroma of a premium spirit. The seven spirit samples were selected to represent a market competitive set, or Benchmark, of products to determine the desired concentrations for each flavor compound. Commercially available flavor reference standards were used to adequately represent the particular characteristics for the purposes of descriptive sensory techniques, as well as chemical analysis. Table 1 presents data from chemical analysis of the of traditional aged spirits with Benchmark Minimum and Benchmark Maximum concentrations as well as the concentrations present in two rapid aged spirits.

TABLE-US-00001 Compound Benchmark Minimum (.Math.g/mL) Benchmark Maximum (.Math.g/mL) Market Spirit 1: Rapid Age -Light + Heat (.Math.g/mL) Market Spirit 2: Rapid Age -Pressure + Heat (.Math.g/mL) Furfural 16,280.5 71,033.7 6,363.8 6,033.5 Nonanoic acid, ethyl ester 291.3 769.4 302.5 290.3 5-methyl-2-Furancarboxaldehyde 963.0 6,659.2.00 466.2 472.6 2,4-Decadienal, (E,E)- 56.5 134.1 49.4 77.3 (E)-β-damascenone 204.4 368.4 ND 49.3 cis-Whiskey lactone 1,295.5 2,508.1 ND 1,699.8 trans-β-Ionone 22.2 43.5 ND 7.4 trans-Whiskey lactone 11,473.6 21,719.1 408.9 13,511.2 Creosol 56.5 166.2 135.4 ND Eugenol 422.4 1,085.2 133.7 720.3

[0014] Flavor reference standards were used to identify the key compounds in the seven traditional spirits used in the Benchmark. The desired flavor compounds were identified with corresponding concentrations by gas chromatography time-of-flight mass spectrometry (GC-MS). The chromatographic separation was performed on an Agilent VF-WAXms column using automatic oven temperature programming. Each compound was identified by a comparison of mass spectra and retention times with the NIST Library and flavor reference standards. Prior to analysis, 1 mL of each spirit product was diluted into 3 mL of aqueous sodium chloride solution and spiked with BHT as an internal standard. The compounds were extracted using solid phase microextraction (SPME) with a Divinylbenzene/Carboxen/Polydimethylsiloxane (DVB/CAR/PDMS) fiber. The quantitative analysis performed on the experimental spirit samples provided a target range for each compound which allowed for the determination of the spirit blend selection, rapid aging process timeline, and oak adjunct selection to specifically match the benchmark.

[0015] The present invention provides a method of producing a blended spirit with characteristics associated with a spirit aged or matured for a much longer period. The method of the invention can produce a spirit with characteristics of a six-to-ten-year aged spirit that can be produced with an average spirit age of less than four years. Chemical and sensory analysis was used to select an appropriate blend of young spirits with varying age, while controlling to minimize the addition of five- to twelve-year-old spirits. GC-MS analysis was used to quantitatively determine each of the spirit’s chemical compound concentration ranges which was used to identify the optimal ratio of the young one-to-three-year spirits, and the more mature five-to-twelve-year spirits to produce the characteristics of a traditionally aged spirit.

[0016] It has been discovered that a product similar to a traditional premium spirit may be produced by blending spirits aged between one and twelve years to form an untreated blended spirit, and using a combination of heat and dissolved oxygen in the presence of wood staves to speed up the chemical reactions of the aging and maturation process. The suite of chemical reactions that transpire in a wooden barrel provides reaction products that are difficult to produce in an inert reaction vessel or in short periods of time such as days or weeks. The use of wood staves allows for the mixing of wood varieties and levels of char to impart different flavors, such as guaiacol, which were not present at the desired concentrations in the untreated blended spirit. The presence of heat and oxygen helps to speed up the chemical processes related to aging and maturation. The combination of heat, oxygen, and wood staves can be applied to the untreated blended spirit for a period of six to twelve weeks while monitoring the levels of key flavor compounds by GC-MS to determine when the desired flavor has been achieved. Exemplary desired flavor compounds and their concentration ranges are presented in Tables 1 and 3. A complete set of compounds that were quantified in the traditional spirit products of the Benchmark is provided in Table 5.

[0017] In Example 1, an untreated blended spirit was created by mixing 50% bourbon aged for two years, 34% bourbon aged three years, and 16% bourbon aged twelve years. Each of the bourbons were aged in new charred oak barrels before being blended. The mash bill breakdown for the untreated blended spirit was 67% Corn, 22% Rye, 6% Wheat, and 5% Malt. The untreated blended bourbon was quantitatively analyzed by GC-MS to determine concentration of target compounds, which were compared to the concentration range in a set of exemplary benchmark bourbons. The Benchmark is composed of seven mass market bourbon whiskeys with suggested retail prices ranging from $35 to $65 per 750 mL bottle with barrel ages ranging from five- to ten-years. The addition of oak barrel characteristics that were found to be lacking in the untreated blended bourbon is achieved by the addition of commercially available charred oak staves. As part of the method of determining the oak adjunct or adjuncts to favorably contribute to the finished product, 20 of the available oak adjuncts were evaluated for flavor, aroma, and tactile impacts by both quantitative and qualitative analysis to establish descriptive sensory characteristics and concentrations of key compounds of interest that under rapid aging conditions would bring the age-blended spirit closer to the chemical representation of a traditionally aged spirit at a molecular level. Chemical contributions from each type of stave were determined by adding each stave separately to a small amount of corn whiskey distillate, which was allowed to extract for a period of six weeks. To evaluate the flavor contributions from each stave, the extract was analyzed by GC-MS to determine the concentration of each desired flavor compound extracted from all 20 oak adjuncts. Out of the 20 commercially available oak adjuncts tested, two were selected to improve the aroma and flavor profile of the untreated blended bourbon. Wood Adjunct 1 utilized in Example 1 was EvOak Rickhouse. Wood Adjunct 2 utilized in Example 2 was Barrel Mill Heavy Toast. The analytical results are presented in Table 2 and the process for Example 2 was identical but for the use of Wood Adjunct 2. These compounds highlight the contribution of flavor compounds from wood adjuncts.

TABLE-US-00002 Compound Untreated Blended Bourbon (.Math.g/mL) Benchmark Average (.Math.g/mL) Example 1 (.Math.g/mL) Example 2 (.Math.g/mL) 2,4-Decadienal, (E,E)- 74.1 86.7 68.0 103.7 (E)-β-damascenone 95.1 257.6 57.9 82.8 cis-Whiskey lactone 3498.2 4124.3 79.6 ND trans-β-Ionone 30.6 34.2 ND 8.8 trans-Whiskey lactone 22541.6 19675.0 474.1 420.6 4-Ethyl guaiacol 326.5 71.0 29.8 32.0 Eugenol 875.1 1093.8 ND ND Phenol, 4-ethyl- 27.5 43.6 ND 17.4 Guaiacol 217.6 352.2 104.7 101.9

Oxygen was also added to the untreated blended spirit using a single channel micro-oxygenation system at a rate of 10 mg/L/month to accelerate oxidation reactions. Samples of the in-treatment blended spirit were analyzed weekly by GC-MS until compounds of furfural, 5-methyl-2-furancarboxaldehyde, guaiacol, and cis-whiskey lactone reached concentrations greater than the minimum benchmark concentrations in Table 1. Once the desired level of each compound was achieved, micro-oxygenation additions were discontinued. The resulting treated spirit was then analyzed again by GC-MS and descriptive sensory analysis methods to ensure the flavor and aroma levels were consistent with the set of benchmark bourbons. Average concentrations of flavor compounds from the benchmark samples were averaged to calculate the Benchmark Average concentrations presented in Table 2. Example 3 was conducted with the use of barrel aged bourbon mixed with raw distilled spirits and placed in a reaction vessel with wood staves for six weeks and kept at 90° F. with the microaddition of oxygen. The product treated spirit (Example 3) was analyzed for the concentration of flavor compounds and compared to the minimum and maximum benchmarks in Table 3.

TABLE-US-00003 Compound Benchmark Minimum (.Math.g/mL) Benchmark Maximum (.Math.g/mL) Example 3 (.Math.g/mL) Furfural 16,280.5.00 71,033.7.00 24,269.64.00 Nonanoic acid, ethyl ester 291.3 769.4 321.99 2-Furancarboxaldehyde, 5-methyl- 963.0 6,659.2.00 1,520.52.00 2,4-Decadienal, (E,E)- 56.5 134.1 98.04 (E)-β-damascenone 204.4 368.4 469.24 Guaiacol 135.8 472.6 146.41 cis-Whiskey lactone 1,295.5.00 2,508.1.00 1,441.21.00 trans-β-Ionone 22.2 43.5 27.48 trans-Whiskey lactone 11,473.6.00 21,719.1.00 8,920.49.00 Creosol 56.5 166.2 120.70 Eugenol 422.4 1,085.2.00 567.88 Vanillin 6,292.7.00 20,044.7.00 11,929.36.00 γ-Nonalactone 82.4 390.6 282.32 γ-Decalactone 20.5 78.7 70.55 Benzeneacetic acid, ethyl ester 166.5 471.7 186.69 1-Pentanol 1,611.0.00 6,488.1.00 1,579.25.00 4-Ethyl guaiacol 41.7 130.6 163.87

[0018] The present invention allows for a combination of traditional barrel aging, blending, and rapid aging that achieves both the desired flavor and smoothness of a traditionally aged bourbon as ensured by chemical analysis and category benchmarking. The use of a traditional barrel aged spirit provides a set of chemical compounds that serve as reagents for chemical reactions to occur in the rapidly aged spirits. Where prior rapid aging approaches have not utilized any barrel aged spirits, the present invention provides the complex chemical variety of compounds in a blended spirit to accelerate the formation of compounds previously only found with barrel aged spirits. The selected variously aged spirits used to create the untreated blended spirit blend are analyzed by GC-MS to determine the presence of desired flavor compounds and relative concentrations. Wood adjuncts suitable for the desired flavor profile of the final treated bourbon are also selected based on analytical chemical investigation of the many wood adjunct flavor profiles and compound concentrations. Preferred adjuncts are added to the untreated blended spirit which produces a chemical reaction resulting in the targeted flavor profile of the final treated spirit. The oxygenation of the blended spirit in the presence of the wood adjunct is also monitored with the use of GC-MS analytical methods to determine the appropriate temporal endpoint of additional oxygenation.

[0019] Another experiment, example 4, was conducted to determine the contribution of flavor compounds contributed or aided by reactions with charred wood. A first spirit liquid, bourbon aged in charred oak barrel for one year, and a second spirit liquid, bourbon aged in a charred oak barrel for five years, were combined to produce an untreated blended spirit and tested for the presence of selected flavor compounds. Additionally, market spirit 3 and market spirit 4 were tested for the concentration of selected flavor compounds. The results are presented in Table 4. Market spirit 3 in this example was Woodford Reserve Kentucky Straight Bourbon. Market spirit 4 was Elijah Craig Small Batch Kentucky Straight Bourbon. The compounds were selected as representative of the composition of aged spirits that are known to have favorable flavor profiles.

[0020] The untreated blended spirit was placed in a stainless-steel reactor vessel and 0.3 mg/l/day of oxygen was added for ten weeks. The temperature was maintained at 90° F. After ten weeks of periodic analysis of the composition of the in-treatment spirit, the addition of heat and oxygen were discontinued and analysis of the selected flavor compounds produced the concentrations listed for Example 4 in Table 4.

TABLE-US-00004 Concentration shown as .Math.g/mL Compound Furfural 5-methyl-2-Furancarboxaldehyde 2,4-Decadienal, (E,E)- (E)-β-damascenone Guaiacol Market Spirit 3 30,754 2,412 64 296 164 Market Spirit 4 33,240 1,392 82 383 244 Spirit blend at start 13,647 806 91 472 172 Spirit blend after 10 weeks 48,029 4,595 141 884 313 Increase in concentration 34,382 3,789 50 412 141 Percent increase in concentration 252% 470% 55% 87% 82%

TABLE-US-00005 Compound cis-Whiskey lactone trans-β-Ionone trans-Whiskey lactone Eugenol Vanillin 4-Ethyl guaiacol Market Spirit 3 1,296 28 11,040 422 16,847 44 Market Spirit 4 2,487 39 20,825 669 16,835 100 Spirit blend at start 1,255 28 8,529 606 3,373 190 Spirit blend after 7 days 3,044 59 9,175 962 5,506 284 Increase in concentration 1,789 31 646 356 2,133 94 Percent increase in concentration 143% 111% 8% 59% 63% 49%

[0021] The combination of rapid aging techniques, selected addition of wood adjuncts, analytical chemistry, blending of raw distillate or young aged spirits with older aged spirits, and category benchmarking provides a rapidly aged spirit with a desirable traditionally aged flavor profile. The concentration increase of furfural by over 200% improves the sweetness of the treated spirit. Guaiacol is contributed by charred wood components and the measured increase of over 80% adds a smoke characteristic to the treated spirit. Cis-Whiskey lactone is a characteristic whiskey flavor compound and is shown to be increased by greater than 100% over the starting concentration. Trans-β-Ionone can impart a floral characteristic to a spirit and is shown here to have increased by more than 100% during treatment. Trans-Whiskey lactone is a whiskey flavor compound and is shown to be increased by greater than 100% over the starting concentration. 5-methyl-2-Furancarbox-aldehyde provides a complex flavor with a spicy-sweet aspect and caramel smell. The concentration shows more than a 400% increase over the starting concentration or more than five times the starting concentration. The increased concentration of these flavor compounds can be selected as action levels either as compared to their starting concentrations, compared to benchmark minimums, or compared to benchmark averages, to determine that the rapid aging process has produced sufficient amounts of desired flavor compounds. Vanillin is shown in Table 4 as having increased by 63% or more than 50% as measured against its starting concentration.

[0022] A method of practicing the invention comprises the steps of providing a first spirit liquid, a second spirit liquid, and optionally a third spirit liquid to create an untreated spirit blend. The first spirit liquid can comprise a young spirit, or one aged in a barrel or oak barrel for six months to a year. The second spirit liquid can comprise a moderate aged spirit or one aged in a barrel for one year to five years. The third spirit liquid can comprise a long-aged spirit or one aged in a barrel for five years to fifteen years. The untreated spirit blend is then analyzed to determine the concentration of a number of flavor compounds. The concentration of these compounds is compared to a benchmark comprising a minimum concentration or an average concentration of the flavor compounds. In an embodiment of the invention, the spirit liquids can comprise Bourbon. The untreated blended spirit is then placed in a reactor vessel with a wood adjunct and heat and oxygen are added over a period of time to increase oxidation and other chemical reactions. The wood adjunct can be selected based on the expected contribution of flavor compounds. Heating and oxygenating in the presence of a wood adjunct provides an in-treatment blended spirit. The in-treatment blended spirit is analyzed for the presence of desired flavor compounds to determine sufficient chemical conversion has been achieved and the rapid aging process has been completed to produce a treated spirit liquid. The invention provides a method of utilizing a combination of traditional barrel aging, blending, and rapid aging that achieves both the desired flavor and smoothness of a traditionally aged spirits such as whisky or bourbon whiskey confirmed by chemical analysis.

[0023] Additional compounds were identified as present in spirits that contribute to a flavor profile of a beverage. A list of flavor compounds of distilled spirits or alcoholic beverages as determined by GC-MS is included in Table 5. These compounds may be used in addition to the compounds listed above to determine the progress and sufficiency of rapid aging in producing a desirable product and establish that conversion of the spirit liquids to a treated spirit is complete.

TABLE-US-00006 Butanoic acid, ethyl ester Octanoic acid, 3-methylbutyl ester 1-Propanol Butanedioic acid, diethyl ester Butanoic acid, 2-methyl-, ethyl ester 1-Decanol Butanoic acid, 3-methyl-, ethyl ester Methyl salicylate 1-Propanol, 2-methyl- Benzeneacetic acid, ethyl ester 1-Butanol, 2-methyl-, acetate 2,4-Decadienal, (E,E)- 1-Butanol, 3-methyl-, acetate Acetic acid, 2-phenylethyl ester Pentanoic acid, ethyl ester (E)-β-damascenone Pentanoic acid, 2-methyl-, ethyl ester Dodecanoic acid, ethyl ester 2-Heptanone Geraniol 1-Butanol, 3-methyl- Guaiacol Hexanoic acid, ethyl ester cis-Whiskey lactone 1-Pentanol Phenylethyl Alcohol p-Cymene trans-β-Ionone Butanoic acid, pentyl ester trans-Whiskey lactone Heptanoic acid, ethyl ester Creosol Propanoic acid, 2-hydroxy-, ethyl ester, (L)- 2-Pentadecanone 1-Hexanol γ-Nonalactone Octanoic acid, methyl ester Phenol, 4-ethyl-2-methoxy- Octanoic acid, ethyl ester Cinnamaldehyde, (E)- Furfural Octanoic acid Acetic acid Ethyl cinnamate Benzaldehyde γ-Decalactone 2-Nonenal, (E)- Eugenol Nonanoic acid, ethyl ester Phenol, 4-ethyl- Linalool n-Decanoic acid 1-Octanol Benzoic acid 2,6-Nonadienal, (E,E)- Dodecanoic acid 2-Furancarboxaldehyde, 5-methyl- Vanillin 2,6-Nonadienal, (E,Z)- trans-Farnesol Decanoic acid, ethyl ester 4-Ethyl guaiacol

[0024] The many features and advantages of the invention are apparent from the detailed specification and, thus, it is intended by the appended claims to cover all such features and advantages of the invention that fall within the true spirit and scope of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.