DISTILLED SPIRITS USING NEGATIVE PRESSURE PROCESSES

RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 62/492,326, filed May 1, 2017, the entire contents of which are incorporated herein by reference in their entirety for all purposes.

TECHNICAL FIELD

[0002] The technical fields are: Food Chemistry and Other Consumer Goods. BACKGROUND ART

[0003] By some accounts, human beings have been aging distilled spirits in wooden containers for almost five hundred years. Despite billions of person-hours of experience, the myriad of chemical reactions responsible for the flavor of wood-aged spirits are not fully understood. Spirits derive their distinct characteristics over time while stored in wooden containers in part from the quicker evaporation of more volatile organic compounds (VOCs) through the barrel walls, over the slower evaporation of other organic compounds. The aging process thus eliminates some undesired compounds, such as methanol, and concentrates and rebalances others, such as flavorful esters formed from reactions with the wood barrel.

[0004] Unfortunately, this aging process is slow, taking decades. The other price paid is lost volume. At a rate of about 2% per year, this so-called "angel's share" can result in a 30% to 50% loss of the original volume of spirits, depending on the storage conditions and duration. What is needed is a means which the quality and complexities associated with traditionally aged spirits can be achieved in a significantly reduced timeframe, sometimes with a reduction in the evaporation of finished goods and a reduction of the build-up of unwanted organic compounds.

SUMMARY

[0005] The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and methods which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the above-described problems have been reduced or eliminated, while other embodiments are directed to other improvements. [0006] Briefly, therefore, one aspect of the present disclosure encompasses a process for maturing a distilled spirit, comprising (a) percolating air through a distilled spirit in a container with a headspace at a gauge pressure between about 25 inHg and about 30 inHg until alcohol concentration of the distilled spirit is reduced by between about 1% to about 2% by volume, and until the total volume of the distilled spirit is reduced by about 10% or less. The distilled spirit in step (a) may begin with an alcohol concentration greater than 60% by volume, and the process may then further comprise (b) diluting the distilled spirit of step (a) with water to an alcohol concentration between about 50% and about 55% by volume, and then (c) percolating air through the diluted distilled spirit in the container with a headspace at a gauge pressure between about -25 inHg and about -30 inHg until the alcohol concentration of the diluted distilled spirit is reduced by an additional amount of between about 0.3% and about 1% by volume.

[0007] In some embodiments, the disclosure provides a process for maturing a distilled spirit, comprising: (a) percolating air through a distilled spirit in a container with a headspace at a gauge pressure between about 27 inHg and about 28 inHg until alcohol concentration of the distilled spirit is reduced by between about 1% to about 2% by volume, as determined by an inline density meter connected to the container with a headspace, and until the total volume of the distilled spirit is reduced by about 10% or less, wherein the distilled spirit begins with an alcohol concentration greater than 60% by volume; and then (b) diluting the distilled spirit of step (a) with water to an alcohol concentration between about 50% and about 55% by volume; and then (c) percolating air through the diluted distilled spirit in the container with the headspace at a gauge pressure between about -27 inHg and about -28 inHg until the alcohol concentration of the diluted distilled spirit is reduced by an additional amount of between about 0.3% and about 1% by volume, as determined by the in-line density meter.

[0008] A distilled spirit may be produced according to any process described herein.

[0009] Additional embodiments and features are set forth in part in the description that follows, and in part will become apparent to those skilled in the art upon examination of the specification, or may be learned by the practice of the embodiments discussed herein. A further understanding of the nature and advantages of certain embodiments may be realized by reference to the remaining portions of the specification and the drawings, which forms a part of this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The disclosure will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements. The drawings provide exemplary embodiments or aspects of the disclosure and do not limit the scope of the disclosure.

[0011] FIG. 1 shows the gas chromatograph mass spectrometry (GCMS) chromatogram from an unprocessed rum sample.

[0012] FIG. 2 shows the GCMS chromatogram from a sample of a commercially available rum which has been aged for 33 years by conventional aging techniques.

DETAILED DESCRIPTION

[0013] This disclosure pertains to processes for producing a distilled spirit having characteristics associated with a mature distilled spirit. The distilled spirit produced in accordance with the process has many of the characteristics associated with a matured distilled spirit produced in accordance with industry standards, but is advantageously produced in a shortened timeframe while reducing the evaporation problem and greatly reducing the "off flavors" associated with excess volatile organic compounds (VOCs), such as methanol an ethyl acetate. By percolating air through a distilled spirit in a container with a headspace at a gauge pressure between about 25 inHg and about 30 inHg until alcohol concentration of the distilled spirit is reduced by between about 1% to about 2% by volume, and until the total volume of the distilled spirit is reduced by about 10% or less, the concentration of unwanted chemical markers is decreased and the concentration of desired chemical markers is increased, without the drastic volume losses associated with traditional aging.

[0014] The distilled spirit in step (a) may begin with an alcohol concentration greater than 60% by volume, and the process may then further comprise (b) diluting the distilled spirit of step (a) with water to an alcohol concentration between about 50% and about 55% by volume, and then (c) percolating air through the diluted distilled spirit in the container with the headspace at a gauge pressure between about -25 inHg and about -30 inHg until the alcohol concentration of the diluted distilled spirit is reduced by an additional amount of between about 0.3% and about 1% by volume. In particular, it has surprisingly been found that the processes described herein produces a spirit having similar chemical markers as a 33-year-old spirit in a significantly reduced period of time.

[0015] Attempts have been made to accelerate maturation of distilled spirits by cycling or varying pressures over relatively large ranges (e.g., between -2 and 10 ATM; see U.S. Patent Publication No. 2013/0149423). These processes generally do not yield a product close enough to that produced by traditional means. Other environmental conditions are more important to achieve characteristics associated with a mature flavor, as presently disclosed.

[0016] Additional embodiments and features are set forth in part in the description that follows, and in part will become apparent to those skilled in the art upon examination of the specification, or may be learned by the practice of the embodiments discussed herein. A further understanding of the nature and advantages of certain embodiments may be realized by reference to the remaining portions of the specification, the drawings, the chemical structures, and descriptions, which forms a part of this disclosure. Any description of any R-group or chemical substituent, alone or in any combination, may be used in any chemical formula described herein, and formulae include all conformational and stereoisomers, including diastereomers, epimers, and enantiomers. Moreover, any feature of a composition disclosed herein may be used in combination with any other feature of a composition disclosed herein,

(a) Distilled Spirits

[0017] As used herein, a spirit refers to any distilled spirit. In particular embodiments, the spirit is a sugar cane-based, grain-based, fruit-based, or agave-based spirit such as rum, tequila, mescal, whiskey, brandy, gin, vodka, or combinations thereof. The distilled spirit may be a sugar cane-based spirit, such as rum. The distilled spirit may be a grain-based spirit, such as whiskey, bourbon, or scotch. The distilled spirit may be a fruit-based, such as brandy. The distilled spirit may be an agave-based spirit, such as tequila or mescal. The distilled spirit may be rum. The distilled spirit may be tequila. The distilled spirit may be mescal. The distilled spirit may be whiskey. The distilled spirit may be brandy. The distilled spirit may be gin. The distilled spirit may be vodka.

[0018] The spirit may be newly distilled or it may have already undergone a standard or accelerated aging process. For example, a 15-year whiskey may be treated as disclosed here to produce a whiskey having a 20-year or 30- year chemical profile. In other words, when a process disclosed herein is applied to aged spirits, the ratios of chemical markers are altered and make the distilled spirit appear much older than it is. The process works on any spirit, including un- aged spirits such as vodka, gin, un-aged rum, un-aged tequila, un-aged brandy (eau de vie), and the like. Here, the process removes the sensation alcohol burn and trace methanol.

[0019] The term "distilled spirit mixture," as used herein, refers to any distillate on the spectrum from matured to unmatured. The term "distillate" as used herein refers to the liquid composition in the container and may include an unmatured distilled spirit, a matured distilled spirit, or a distilled spirit mixture. The unmatured distilled spirit is a spirit that has not attained the markers or characteristics associated with a matured distilled spirit. The "unmatured distilled spirit," as described herein, refers to white or raw spirits, as well as partially matured spirits, provided that the unmatured distilled spirit is lacking in certain characteristics of a matured spirit.

[0020] A distilled spirit having the characteristics associated with a matured distilled spirit, as used herein, describes a spirit, which, by one or more chemical markers, has attained characteristics associated with spirits aged in accordance with industry standards. Such standards, for example, include aging a spirit in wood over a period of time greater than 1, 5, 10, 15, 20, 25 or 30 years. The characteristics associated with a matured distilled spirit may include taste, aroma, and body profiles, such as smoothness,

(b) Percolation

[0021] In the process provided herein, air is percolated through a distilled spirit in a container with a headspace until the alcohol concentration of the distilled spirit is reduced. "Percolating" refers to gas aspirating or filtering gradually through a porous surface or substance. The air may be untreated air from the ambient atmosphere, or it may be filtered, dried, and or deoxygenated air. Alternatively, the air may comprise one or more gases selected from the group consisting of nitrogen, oxygen, argon, water, carbon dioxide, and helium, which are the principal gases of the terrestrial atmosphere.

[0022] In particular, the concentration of water in the air may be adjusted to attain a particular "relative humidity," which is the ratio of the amount of water vapor actually present in the air to the greatest amount possible at the same temperature. Without wishing to be bound by theory, a high relative humidity leads to a net loss of alcohol, whereas a low relatively humidity leads to a net loss of water. The relative humidity (RH) of the air may be selected from between about 0% and about 100%, such as between about 0% and about 10%, between about 10% and about 20%, between about 20% and about 30%, between about 30% and about 40%, between about 40% and about 50%, between about 50% and about 60%, between about 60% and about 70%, between about 70% and about 80%, between about 80% and about 90%, or between about 90% and about 100%. The relative humidity may be selected to mimic a geographical location, for example, Kentucky, Scotland, or Jamaica.

[0023] Generally, the air is introduced into to the container is at about atmospheric pressure. An air inlet at the bottom of the container permits the air to contact the distilled spirits. In large containers, the air inlet may be fluidly connected to a diffuser or perforated disk to distribute the air over a larger surface area, thus enhancing contact between the air and the distilled spirit.

[0024] During the process, the headspace of the container is under controlled negative gauge pressure. Although the container is open to the atmosphere or an air source, thereby allowing the air to percolate through, the headspace is enclosed by the top surface of the distilled spirit and the walls of the container, thereby allowing a negative gauge pressure to be exerted. Absolute pressure is zero-referenced against a perfect vacuum, so it is equal to gauge pressure plus atmospheric pressure. Gauge pressure is zero -referenced against ambient air pressure, so it is equal to absolute pressure minus atmospheric pressure, wherever the gauge is located. In stating the gauge pressure, negative signs may be omitted, but are used herein for clarity.

[0025] "Inch of mercury" (inches of Hg, inHg, or "Hg) is a unit of measurement for pressure exerted by a column of mercury of 1 inch (25.4 mm) in height at the standard acceleration of gravity. This simple gauge measures the difference in the levels of the mercury from 0 inches at atmospheric pressure up to 29.92 inches of Hg at the best vacuum attainable. Typically, this scale is shown as 0 to 30 inches of Hg on gauges, such a Bourdon dial gauges.

[0026] The range of gauge pressures used herein can and will vary. The gauge pressure of the headspace inside the container may be between about 25 inHg and about 30 inHg, such as between about 25 inHg and about 25.5 inHg, between about 25.5 inHg and about 26 inHg, between about 26 inHg and about 26.5 inHg, between about 26.5 inHg and about 27 inHg, between about 27 inHg and about 27.5 inHg, between about 27.5 inHg and about 28 inHg, between about 28 inHg and about 28.5 inHg, between about 28.5 inHg and about 29 inHg, between about 29 inHg and about 29.5 inHg, or between about 29.5 inHg and about 30 inHg. The gauge pressure may be between about 27 inHg and about 28 inHg. In particular, the gauge pressure may be about 27.75 inHg. [0027] During the process, the distilled spirit may chill due to evaporative cooling, especially in large batches. As such, the temperature of the distilled spirit may be heated during the process to hold the temperature constant. Alternatively, the temperature may be lowered or raised relative to the ambient conditions. In these embodiments, the temperature may range from between about 0 °F and about 140 °F, such as between about 0 °F and about 10 °F, between about 10 °F and about 20 °F, between about 20 °F and about 30 °F, between about 30 °F and about 40 °F, between about 40 °F and about 50 °F, between about 50 °F and about 60 °F, between about 60 °F and about 70 °F, between about 70 °F and about 80 °F, between about 80 °F and about 90 °F, between about 90 °F and about 100 °F, between about 100 °F and about 110 °F, between about 110 °F and about 120 °F, between about 120 °F and about 130 °F, or between about 130 °F and about 140 °F. The temperature may be greater than 0 °F. The temperature may be less than 140 °F.

[0028] The volume of distilled spirits used in the process can and will vary. For example, the volume may range from about 100 mL to about 10,000 L, such as between about 100 mL and about 500 mL, between about 500 mL and about 1 L, between about 1 L and about 1.5 L, between about 1.5 L and about 2 L, between about 2 L and about 5 L, between about 5 L and about 10 L, between about 10 L and about 50 L, between about 50 L and about 100 L, between about 100 L and about 500 L, between about 500 L and about 1,000 L, between about 1,000 L and about 2,000 L, between about 2,000 L and about 5,000 L, or between about 5,000 L and about 10,000 L. The volume may be greater than about 100 mL. The volume may be less than about 10,000 L. The volume may be about 325 mL. The volume may be about 750 mL. The volume may be about 1.5 L.

[0029] The process disclosed herein decreases the concentration of alcohol within the distilled spirit, and thereby selectively removes the most volatile organic compounds and azeotropes and/or increases the concentration of desirable chemical markers. The disclosed process is very sensitive and is preferably monitored carefully to the target alcohol concentration. (As used throughout this disclosure, "alcohol" without further qualification takes its common meaning of "ethanol.") The alcohol concentration of the distilled spirit may be determined during the process using an in-line density meter connected to the container. In these embodiments, the vacuum chamber should be fitted with an in-line density meter to carefully monitor the changes in alcohol percentage in the spirit, allowing for very precise processing. An in-line density meter is critical to scaling the system to larger volumes. If the disclosed process is run too long, the distilled spirits becomes very bitter. If the disclosed process is run for too short of a time, the distilled spirit retains chemical markers which gives the perception of heat to a consumer.

[0030] The disclosed process can be used on either full strength spirits or bottling strength spirits with the adjustments to the target alcohol concentration, as described herein. The unmatured distilled spirit, as described herein, has an alcohol content of at least 50% by volume. In some embodiments, the alcohol content of the unmature distilled spirit is between 40% and 95.5% by volume. "Full strength" is the strength of distilled spirit straight from the cask (barrel) with no water added. Full strength spirits typically have an alcohol concentration of greater than 60% by volume, such as greater than 65%, as greater than 70%, as greater than 75%, as greater than 80%, as greater than 85%, or as greater than 90% by volume. The initial concentration of alcohol may be between about 40% and about 95.5% by volume. "Bottling strength" refers to the concentration to which distilled spirits are diluted to when transferring from the cask (barrel) to a bottle, which is between about 40% and about 57% by volume for most bottled spirits, such as between about between about 40% and about 45% by volume, between about 45% and about 50% by volume 50% and about 55% by volume, or between about 52% and about 57% by volume.

[0031] As such, the alcohol concentration of full strength distilled spirit may be reduced by between about 1% to about 2% by volume, such as between about 1.1% to about 1.2% by volume, between about 1.2% to about 1.3% by volume, between about 1.3% to about 1.4% by volume, between about 1.4% to about 1.5% by volume, between about 1.5% to about 1.6% by volume, between about 1.6% to about 1.7% by volume, between about 1.7% to about 1.8% by volume, between about 1.8% to about 1.9% by volume, or between about 1.9% to about 2.0% by volume. As such, the alcohol concentration of bottle strength distilled spirit may be reduced by between about 0.3% to about 1% by volume, such as between about 0.3% to about 0.4% by volume, between about 0.4% to about 0.5% by volume, between about 0.5% to about 0.6% by volume, between about 0.6% to about 0.7% by volume, between about 0.7% to about 0.8% by volume, between about 0.8% to about 0.9% by volume, or between about 0.9% to about 1.0% by volume.

[0032] Unlike traditional methods, which lose about 30% to about 50% of the volume to evaporation in the barrelhouse, the disclosed process removes less than about 20% of the total volume of the spirit, while creating substantially the same flavor characteristics as associated with very old spirits. For example, the disclosed process may remove less than about 20% of the total volume of the spirit, such as less than about 19%, less than about 18%, less than about 17%, less than about 16%, less than about 15%, less than about 14%, less than about 13%, less than about 12%, less than about 11%, less than about 10%, less than about 9%, less than about 8%, less than about 7%, less than about 6%, less than about 5%, less than about 4%, less than about 3%, less than about 2%, or less than about 2% of the total volume of the spirit. As described above, the parameters selected for the process determine whether the net loss from the lost volume is net water or net alcohol,

(c) Chemical markers

[0033] The disclosed process rapidly removes undesired chemical markers and concentrates desired chemical markers. A mature distilled spirit having the characteristics associated with a matured distilled spirit, as used herein, describes a spirit, which has attained a flavor and aroma profile organoleptically similar to spirits aged with wood for many years, and typically showing a chemical profile containing key chemical markers in particular proportions.

[0034] Traditionally, producing wood-aged distilled spirits has included carboxylic acid esterification, phenolic acid esterification, and the formation of complex esters, including both phenolic and carboxylic acids. Carboxylic acid esters are responsible for the fruity aromas and tastes in distilled spirits. Carboxylic precursor acids are derived from the yeast and bacteria during fermentation. If organic materials are used for the container in which these reactions occur, those materials also influence the process. For example, where a charred or toasted oak barrel is used, carboxylic precursor acids are also derived from thermal decomposition of the oak polymer, hemi-cellulose, found in the inner lining of the barrel.

[0035] Off-flavors are various flavorful or aromatic compounds present in spirits that are often described by connoisseurs using colorful terms (e.g., "sulfury", "solventy", "meaty", "acidic", "metallic", "vegetal", etc.). Carboxylic precursor acids are largely responsible for "off- flavors" in distilled spirits. Another common flaw with a solvent-like "off flavor" is produced by build-up of ethyl acetate in the maturing spirit. Other compounds, such as methanol, may not impact flavor but do diminish the consumers' enjoyment of the distilled spirit.

[0036] The disclosed process favors the removal of methanol above other compounds present in distilled spirits. Previously known methods were very costly to remove methanol from distilled spirits. Methanol is partly responsible for hangovers and its removal is critical for consumer quality perceptions. Without wishing to be bound by theory, methanol is removed from the distilled spirit as its azeotrope or eutectic. When a second sequential negative pressure treatment is used, the distilled spirits are diluted with water to bottling strength, thereby changing the azeotropic distribution within the spirits. The method may also remove the perception of heat in all types of spirits. This is something consumers use to perceive quality in distilled spirits.

[0037] Historically, ethyl acetate concentration was used as a marker for the progress of aging where higher amounts indicate greater maturation time. But, ethyl acetate is not itself desirable and adds a flavor and aroma comparable to paint thinners. Moreover, samples of distilled spirits receiving high reviews, comparable or in some cases better than an aged spirit, do not always have a high ethyl acetate concentration. Using modern techniques, highly prized spirits can be analyzed for their chemical make-up. Using these data, chemical markers can be selected as a model for a mature spirit. Surprisingly, these chemical markers provide advantages over the traditional measurement of ethyl acetate concentration to determine age. In particular, the chemical markers set forth herein are desirable for modeling purposes because, unlike ethyl acetate, the chemical markers contribute to the desired flavor profile. In one embodiment, ethyl acetate concentrations are reduced to a concentration less than about 200,000 μg/L. In another embodiment, the ethyl acetate concentrations range between about 50,000 μg/L and about 170,000 μg/L.

[0038] Fatty acids are structurally simple and even with their derivatives can be subdivided into well-defined families. Among straight-chain fatty acids, the simplest are referred to as saturated fatty acids. They have no unsaturated linkages in the carbon backbone and cannot be altered during hydrogenation or halogenation process. Saturated fatty acids tend to be solid at room temperature and their melting points increase with increasing chain length.

[0039] The fatty acid chain lengths may range between 2 and 80 carbon atoms, and commonly between 12 and 24 carbons. With a chain length between 2 and 6 carbon atoms, the fatty acids are called short-chained fatty acids, or C2-C6 acids. Examples of suitable short-chain fatty acids include, but not limited to, formic acid, acetic acid, proprionic acid, butyric acid, isobutyric acid, valeric acid, and isovaleric acid. C2-C6 fatty acid esters include ethyl acetate. [0040] With a chain length from 6 to 12 carbon atoms, the fatty acids are called medium- chained fatty acids, or C6-C12 fatty acids. A common subgroup of medium-chained fatty acids is C8-C10 fatty acids, having 8 to 10 carbon atoms in the chain. Examples of suitable medium- chain fatty acids include, but are not limited to, caproic acid (C6), enanthic acid (C7), caprylic acid (C8), pelargonic acid (C9), capric acid (CIO), undecylic acid (Cl l), and lauric acid (C12).

[0041] With a chain length between 12 and 24, the fatty acids are called a long-chained fatty acids, or C12-C24 fatty acids. The same chain length ranges apply to fatty acid derivatives, such as fatty acid esters. Examples of suitable long-chain fatty acids include, but are not limited to, tridecylic acid (C13), myristic acid (C14), pentadecanoic acid (C15), palmitic acid (C16), margaric acid (C17), stearic acid (C18), nonadecylic acid (C19), arachidic acid (C20), and heneicosylic acid (C21).

[0042] The fatty acids may be unsaturated, such as an ω-3 unsaturated fatty acid, for example, a-linolenic acid (18:3), stearidonic acid (18:4), eicosapentaenoic acid (20:5), and docosahexaenoic acid (22:6); an ω-6 unsaturated fatty acid linoleic acid (18:2), γ-linolenic acid (18:3), dihomo-y-linolenic acid (20:3), arachidonic acid (20:4), and adrenic acid (22:4); an ω-7 unsaturated fatty acid, for example palmitoleic acid (16: 1), vaccenic acid (18:1), and paullinic acid (20: 1); or an ω-9 unsaturated fatty acid, for example oleic acid (18:1), elaidic acid (trans- 18: 1), gondoic acid (20: 1), erucic acid (22:1), nervonic acid (24:1), and mead acid (20:3).

[0043] Fischer esterification of fatty acids and alcohol is a well-understood and commonly practiced chemical reaction. A typical laboratory process involves heating a solution of fatty acids and alcohols under reflux in the presence of an acid catalyst. In laboratory settings, strong acids (e.g., sulfuric acid) are typically employed as the catalyst, but this can be incompatible with spirit making where other functional groups are sensitive to stronger acids and where chemical additives are typically prohibited. It has long been known that Fischer esterification can also be completed using weak acid catalysts, but at the expense of relatively slow reaction rates. Where charred or toasted oak barrels are used during the maturation of distilled spirits, weak acids may be gradually extracted from organic material in the walls of the barrel. It typically takes years for esters to accumulate using weak acid catalysts derived from the barrel, although it has been observed that in warmer environments (i.e., modestly heated within the range of normal atmospheric conditions less than 120 °F) the process can be accelerated significantly (from decades to years). This early form of accelerated aging comes at the cost of increased evaporation from the barrel. Often as much as 50% of the product can be lost to evaporation.

[0044] When the alcohol component is glycerol, the fatty acid esters produced can be monoglycerides, diglycerides, or triglycerides. Dietary fats are chemically triglycerides. Suitable examples of fatty acid esters include, but are not limited to 2- arachidonoylglycerol,ascorbyl palmitate, ascorbyl stearate, cetyl myristoleate, cetyl palmitate, ethyl decadienoate, ethyl decanoate, ethyl eicosapentaenoic acid, ethyl macadamiate, ethyl octanoate, ethyl palmitate, ethylhexyl palmitate, glycerol monostearate, glyceryl hydroxystearate, glycol distearate, glycol stearate, isopropyl palmitate, monoctanoin, monolaurin, 2-oleoylglycerol, polyglycerol polyricinoleate, and virodhamine.

[0045] Phenolic aldehydes also play a major role producing aromas similar to vanilla, pipe tobacco, and smoke. Phenolic aldehydes are largely derived from thermally broken down oak polymers found within the inner lining of the barrel. Complex esters are responsible for complex honeyed aromas in distilled spirits. The complex esters are generally produced from the chemical reactions of both carboxylic and phenolic acids/aldehydes with alcohols during the time in the barrel or other container. Phenolic aldehydes are derivatives of phenol. Suitable examples of phenolic aldehydes include, but are not limited to, hydroxybenzaldehydes, protocatechuic aldehyde, vanillin, isovanillin, 2,3,4-trihydroxy benzaldehyde, sinapaldehyde (3-(4-Hydroxy- 3,5-dimethoxyphenyl)prop-2-enal), and syringaldehyde (4-hydroxy-3,5-dimethoxybenzaldehyde)

[0046] Wood extraction is the process that gives distilled spirits their color and astringent "oaky" and "smoky" taste. Traditionally, this is attributed to tannins (polyphenols). Interestingly our analysis of mature spirits did not find significant evidence of tannins. But instead found myriad less complex wood derived phenols such as sinapaldehyde and syringaldehyde. These oak-extracted compounds proved unexpectedly useful as markers for monitoring the aging process described below.

[0047] Esterification and the extraction of wood compounds from the wood container are some of the primary reactions taking place in the maturation process of distilled spirits. Because these processes run concurrently, and often interact with or depend on each other as well as the material and other conditions of their environment over time, it is very difficult to deviate very far from traditional methods while still achieving similar results. For example, rapid oak extraction may not provide enough time for interaction with a wood container to pick up some of the more subtle and complex flavors present in traditionally aged spirits. Much of the expense in spirit making stems from the long latency in creating the end product as well as the product evaporation from the barrel. Stock must be stored, often in climate-controlled environments, and tested repeatedly during maturation. But, it is difficult to predict markets many years out. Makers that produce too much product fail to maximize their investment, whereas those that produce too little fail to capture potentially significant portions of the upside.

[0048] In one embodiment, a mature spirit can be characterized by the decreasing concentrations of one or more chemical markers. Through operation of a process disclosed herein, the concentration in the distilled spirit may decrease for one or more chemical markers selected from the group consisting of methanol, C2-C6 fatty acids, and C2-C6 fatty acid esters.

[0049] The concentration in the distilled spirit may increase for one or more chemical markers selected from the group consisting of vanillin, phenylated esters, C7-C24 fatty acid esters, and phenolic aldehydes. These things are responsible for the flavor described as the "finish" in distilled spirits. Three markers in particular, are thought to be particularly useful for defining a mature spirit: sinapaldehyde, ethyl decanoate, and ethyl dodecanoate. Ethyl decanoate and ethyl dodecanoate are often found in unmature spirits at low concentrations. Sinapaldehyde is typically not found in an unmature spirit.

[0050] The distilled spirit may be characterized by an increase in concentration of sinapaldehyde, ethyl dodecanoate, and ethyl decanoate. The distilled spirit may be characterized by an increase in concentration of sinapaldehyde. In one embodiment, a mature spirit may be characterized by an increase of at least about threefold for ethyl dodecanoate over an unmature spirit. In another embodiment, a mature spirit is characterized by an increase of at least about threefold for ethyl decanoate over an unmature spirit. Increased concentrations may be assessed by any method known in the art.

[0051] A spirit that presents these three compounds in relative proportion (as assessed by peak height measured by gas chromatography mass spectrometry (GCMS)) typically has desirable flavor characteristics. In this regard, a mature spirit may also be characterized by a sinapaldehyde peak greater than 80% and less than 200% of the peak height of ethyl decanoate and ethyl dodecanoate as measured by GCMS. Without being bound to any theory, it is believed that sinapaldehyde concentration is disproportionately important in creating a spirit that meets the organoleptic properties of a mature spirit. (d) Sequential Pressure Processing

[0052] One aspect of the present disclosure provides a process for maturing a distilled spirit using sequential pressure processing. In this regard, the process comprises the steps describe above, wherein the distilled spirit in step (a) begins with an alcohol concentration greater than 60% by volume. The process then further comprises (b) diluting the distilled spirit of step (a) with water to an alcohol concentration between about 50% and about 55% by volume, and then (c) percolating air through the diluted distilled spirit in the container with the headspace at a gauge pressure between about -25 inHg and about -30 inHg until the alcohol concentration of the diluted distilled spirit is reduced an additional amount of between about 0.3% and about 1% by volume. The alcohol concentration of the distilled spirit may be determined during the process using an in-line density meter connected to the container.

[0053] As in the first sequence of pressure treatment, the gauge pressure may be between about 27 inHg and about 28 inHg, such as at about 27.75 inHg. Any pressure described herein is sufficient.

[0054] The temperature of the distilled spirit may be held constant during the step (b).

[0055] In particular, the present disclosure provides a process for maturing a distilled spirit, (a) Air percolated through a distilled spirit in a container with a headspace at a gauge pressure between about 27 inHg and about 28 inHg until alcohol concentration of the distilled spirit is reduced by between about 1% to about 2% by volume, as determined by an in-line density meter connected to the container. In this process, the total volume of the spirit is reduced by about 10% or less. The distilled spirit begins step (a) with an alcohol concentration greater than 60% by volume. And then optionally, (b) air is percolated through the distilled spirit of step (a) in the container with the headspace at a gauge pressure between about 27 inHg and about -28 inHg until the alcohol concentration of the distilled spirit is reduced by an additional amount of between about 0.3% and about 1% by volume, as determined by the in-line density meter. And then (c) the distilled spirit of step (b) is diluted with water to an alcohol concentration between about 50% and about 55% by volume. And then (d) air is percolated air through the diluted distilled spirit in the container with the headspace at a gauge pressure between about -27 inHg and about -28 inHg until the alcohol concentration of the diluted distilled spirit is reduced by an additional amount of between about 0.3% and about 1% by volume, as determined by the in-line density meter. [0056] As described elsewhere in this disclosure, the distilled spirit may be selected from the group consisting of sugar cane spirits, grain spirits, fruit spirits, or agave spirits. Alternatively, the distilled spirit may be selected from the group consisting of rum, tequila, mescal, whiskey, brandy, gin, and vodka.

[0057] The gauge pressure in each of steps (a) and (c) may be about -27.75 inHg. The temperature of the distilled spirit may be held constant during each of steps (a), (b), and (c).

[0058] The concentration in the distilled spirit may be decreased for one or more chemical markers selected from the group consisting of methanol, C2-C6 fatty acids, and C2-C6 fatty acid esters. Alternatively or in addition, the concentration in the distilled spirit may be increased for one or more chemical markers selected from the group consisting of vanillin, phenylated esters, C7-C24 fatty acid esters, and phenolic aldehydes. In particular, the distilled spirit may be characterized by an increase in concentration of sinapaldehyde, ethyl dodecanoate, and ethyl decanoate. The distilled spirit may characterized by an increase in concentration of sinapaldehyde.

[0059] The total loss of volume of distilled spirits during the process may be less than about 20%.

(e) Optional Further Processing

[0060] Optionally, the spirit produced by the process described herein may be followed by one or more additional pressure processing steps. In one embodiment, the sequential process may be repeated until a desired chemical marker profile is obtained.

[0061] The present disclosure also provides a distilled spirit produced according to a process described herein.

[0062] The compounds described herein have asymmetric centers. Compounds of the present disclosure containing an asymmetrically substituted atom may be isolated in optically active or racemic form. All chiral, diastereomeric, racemic forms and all geometric isomeric forms of a structure are intended, unless the specific stereochemistry or isomeric form is specifically indicated.

[0063] When introducing elements of the present disclosure or the embodiments(s) thereof, the articles "a," "an," "the," and "said" are intended to mean that there are one or more of the elements. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements. [0064] Having described the disclosure in detail, it will be apparent that modifications and variations are possible without departing from the scope of the disclosure defined in the appended claims.

EXAMPLES

[0065] The following examples are included to demonstrate certain embodiments of the disclosure. It should be appreciated by those of skill in the art that the techniques disclosed in the examples represent techniques discovered by the inventors to function well in the practice of the disclosure. Those of skill in the art should, however, in light of the present disclosure, appreciate that many changes can be made in the specific embodiments that are disclosed and still obtain a like or similar result without departing from the spirit and scope of the disclosure, therefore all matter set forth is to be interpreted as illustrative and not in a limiting sense.

Instrumentation.

[0066] Gas Chromatography Mass Spectrometry (GCMS) Data was obtained using a Shimadazu GCMS Model QP2010 with a Restek Column - Rxi-5Sil MS, 30 meter, 0.24 mmID, 0.24 umdf. Program conditions were as follows:

[0067] TABLE 1: Analytical Line 1

Syringe Injection Position :0.0 mm

Solvent Selection :A11 A,B,C

TABLE 2: GC PARAMETERS

Column Oven Temp. :35.0 °C

Injection Temp. :265.0 °C

Injection Mode :Split

Flow Control Mode :Linear Velocity

Pressure :56.0 kPa

Total Flow :23.9 mL/min

Column Flow :1.12 mL/min

Linear Velocity :38.0 cm/sec

Purge Flow :0.5 mL/min

Split Ratio :20.0

High Pressure Injection :OFF

Carrier Gas Saver :ON

Carrier Gas Saver Split Ratio :5.0

Carrier Gas Saver Time : 10.00 min

TABLE 3: OVEN TEMP. PROGRAM

TABLE 4: MS PARAMETERS

Threshold :500

Start Time : 1.80min

End Time :23.00min

ACQ Mode :Scan

Event Time :0.50sec

Scan Speed : 1000

Start m/z :35.00

End m/z :500.00

Comparative Example 1 : Fresh Rum

[0068] A sample of fresh, immature pot distilled rum was analyzed by GCMS. FIG. 1 shows the semi- volatile fingerprint of an un-aged pot distilled rum. This is largely defined by a lack of activity for compounds having a retention time ranging from 5 to 30 minutes. Noteworthy characteristics include, but are not limited to the starting height of peak 1 corresponding to acetyl, peak 2 corresponding to ethyl decanoate, and peak 3 corresponding to ethyl dodecanoate. The absence of a peak for sinapaldehyde, which is described further in later examples, is noteworthy. FIG. 1 also shows an absence of white noise in the chromatogram starting at the 6 minute retention time point.

[0069] Concentration of ethyl acetate was measured by direct injection mass spectrometry. The concentration of ethyl acetate was shown to be about 110,000 μg/L.

Comparative Example 2: Rum Aged for 33 Years by Conventional Aging Process

[0070] A sample of a commercially-available rum which has been aged for 33 years by conventional aging processes was also analyzed by GCMS. FIG. 2 illustrates a semivolatiles profile characteristic of 33 year aged pot distilled rums. Key characteristics include the high acetal spike (peak 1) the high ethyl decanoate spike (peak 2) the high ethyl dodecanoate spike (peak 3) and the high sinapaldehyde spike (peak #4). The relative heights of peaks 2, 3, and 4 in relation to each other are also important. Organoleptically maintaining this approximate ratio of peak heights to each other proved significant for creating the flavor characteristics associated with aged rum. Further noteworthy is the cluster of medium level peaks centered on the 15- minute mark (thought to be caramel additives and found to include significant amounts of glucose - this phenomena was also observed in known adulterated rum).

[0071] The critical differences between the un-aged rum and the 33 year-old rum, that were ascertainable in the semi-volatile chromatograms included the presence of sinapaldehyde (not found in the white rum) alongside peaks showing significantly elevated ethyl decanoate and ethyl dodecanoate levels (both of which are found in the white rum characterized by relatively low peak values). Finally a significant layer of "white noise" (representing a complex mixture of many semi-volatile compounds) lined the bottom of the chromatogram in the 33 years old rum and was absent in the un-aged rum.

[0072] Concentration of ethyl acetate was measured by direct injection mass spectrometry. The concentration of ethyl acetate was shown to be about 770,000 μg/L. A more typical reading for ethyl acetate in a 33 year-old sample is 200,000 μg/L.

[0073] While specific embodiments have been described above with reference to the disclosed embodiments and examples, such embodiments are only illustrative and do not limit the scope of the disclosure. Changes and modifications can be made in accordance with ordinary skill in the art without departing from the disclosure in its broader aspects as defined in the following claims.