SINGLE-SERVE CAPSULE FOR PREPARING A BEER-TYPE DRINK

Abstract

The present invention relates to a single-serving capsule for preparing a hoppy alcoholic beverage with a foam height. This capsule is characterized in that it comprises at least two compartments, including a first compartment and a second compartment; the first compartment comprising 5-30 mL of an aqueous liquid having an ethanol content of 0-10% ABV and comprising 0.1-25% by weight of protein; the second compartment comprising 5-50 mL of an alcoholic liquid containing 20-99.9% by weight of ethanol, 0-60% by weight of water, and 50-2,000 mg / kg of hop acids selected from iso-alpha acid, hydrogenated iso-alpha acids, hulupones, and combinations thereof; wherein the ethanol and water together constitute at least 80% by weight of the alcoholic liquid.

Description

SINGLE-SERVE CAPSULE FOR PREPARING A BEER-TYPE DRINK / CCfr Ln / Zznz / E / YIAI FIELD OF INVENTION The present invention relates to a single-serving capsule for preparing a beer-like beverage. More particularly, the invention relates to a capsule whose contents can be mixed with carbonated water to produce a hoppy alcoholic beverage with a foam height. The single-serving capsule has at least two compartments, including a first and a second compartment. The first compartment comprises an aqueous liquid having an ethanol content of 0-10% ABV and comprising 0.1-25% protein by weight. The second compartment comprises an alcoholic liquid containing 20-99.9% ethanol by weight, 0-60% water by weight, and 30-2,000 mg / kg of hop acids selected from iso-alpha acids, hydrogenated iso-alpha acids, hulupones, and combinations thereof, wherein the ethanol and water together constitute at least 80% by weight of the alcoholic liquid. Furthermore, the invention relates to a process for preparing a hoppy alcoholic beverage with a foam height of this capsule, this method comprising • introducing the single-serving capsule into a beverage preparation device; • release the aqueous fluid from the first compartment; • release the alcoholic liquid from the second compartment; • combine the released aqueous liquid, the released alcoholic liquid, water, and carbon dioxide to produce a hoppy alcoholic beverage; • Dispense the hoppy alcoholic beverage to produce a hoppy alcoholic beverage with a height of foam. BACKGROUND OF THE INVENTION The four basic ingredients used in brewing beer are malted barley, hops, yeast, and water. Malted barley and other ingredients provide starch. The starch is converted into fermentable sugars during mashing. During yeast fermentation, these fermentable sugars are converted into alcohol. The proteins derived from the malted barley and other ingredients act as foaming agents, allowing for the formation of a stable head of foam when the beer is dispensed. During the brewing process, hops are added at the beginning of the boil to impart bitterness to the wort, and more are added at the end of the boil for aroma and flavor. Hops are the cone-shaped female flower of the vine-like plant Humulus lupulus. Hops are harvested, then dried and processed into pellets, plugs, extracts, or left in their cone shape. The most important hop compounds are hop acids, which can be distinguished as alpha acids (or humulones) and beta acids (or lupulones). Neither alpha nor beta acids are responsible for the bitterness of hopped beer. During the wort boil, the thermal isomerization of alpha acids produces iso-alpha acids, which are largely responsible for the hop-derived bitterness in beer. It is known that the light stability of beers is improved by the hydrogenation of α-alpha acids to produce bitter-tasting dihydro, tetrahydro, and hexahydro α-alpha acids. It is also known that oxidized beta acids, more particularly hulupones, can be used to impart hop-derived bitterness to beer. The popularity of appliances for preparing and dispensing carbonated beverages from concentrated syrup, such as Sodastream®, has grown rapidly. These devices produce carbonated beverages by carbonating water and mixing the carbonated water with a flavored syrup. Given the high flexibility and convenience offered by these appliances, it would be desirable to expand the range of beverages that can be produced in this way to include more complex flavor combinations. The benefits of producing beverages from concentrate have been recognized in the field. However, producing concentrates with adequate physicochemical stability that can be properly used to produce a good quality hoppy alcoholic beverage with sufficient head height presents a challenging task. Preparing cold drinks in vending machines by reconstituting a powder usually has the disadvantage that the powder does not dissolve effectively during the mixing process. This results in dispensed drinks of poor quality and damages the machine due to residue buildup. Liquid beverage concentrates offer the advantage of rapid dilution without leaving any residue. However, producing liquid beverage concentrates with sufficient physical and chemical stability is challenging. For concentrates used in beer-like beverages, providing a sufficiently stable liquid concentrate that can be reconstituted to form a good-tasting beverage with a consistent head height is particularly challenging. The stability of liquid concentrates can be negatively affected by the precipitation of solutes (e.g., proteins, sugars, hop acids) and / or reactions between solutes (e.g., between acids and ethanol). US 2016 / 230133 describes a method for preparing a concentrate from an alcoholic beverage, comprising: / CCfr Ln / Zznz / E / YIAI • subject an alcoholic beverage to a membrane process whereby at least some water and alcohol pass through a membrane to become part of a permeate product and other components of the alcoholic beverage do not pass through the membrane and become part of a retained product; • Freeze the water in the retained product to form ice; and • Remove the ice from the retained product to reduce the water content and form a beverage concentrate that has a solids concentration of at least 30% and an alcohol concentration of 20% or less. US 2016 / 0073673 describes a beverage precursor useful for preparing a beer-flavored beverage, the beverage precursor comprising at least one flavor compound selected from a first group of compounds, at least one flavor compound selected from a second group of compounds, and at least one compound selected from a third group of compounds; the first group of compounds consisting of 3-methylbutanol, 2-methylbutanol, 2,3-butanedione, vanillin, 2-methylpropanol, 3-methylbutanal, 2,3-pentanedione, 2-methylpropanal, 2-methylbutanal, furaneol, 2-aminoacetophenone, furfural and ethylfuraneol; the second group consisting of 2-phenylethanol, 2-phenylacetic acid, 2-phenylethyl acetate, phenylacetaldehyde, myrcene, geraniol, b-citronellol and linalool; and the third group consisting of hop extract, tetra-iso 10% extract, rho-iso 10% extract, isomerized hop extract 30%, cis-isohumolone, trans-isohumolone, cisisocohumulone, trans-isocohumulone, iso-adhumulone, and comultifidolglycoside; and the beverage precursor can be mixed with water, ethanol, and / or vodka to form a beverage that tastes like beer without brewing, fermentation, or distillation. US 2016 / 0280455 describes a disposable beverage-forming apparatus container for making a beverage when a liquid is supplied to the disposable container by the beverage-forming apparatus. The disposable container comprises: a watertight, breakable capsule including a bottom wall and a tubular side wall extending upward from the bottom wall, defining an interior space containing a flavoring medium. The flavoring medium may have the aroma, flavor, and / or mouthfeel of beer, wine, sparkling wine, cider, whiskey, gin, vermouth, rum, tequila, and / or a mixed alcoholic beverage. WO 2017 / 167865 relates to a single-serving container comprising a malt-based beverage concentrate or fermented beverage concentrate, characterized in that this concentrate is in a liquid state, has a dynamic viscosity of at least 40.103 mPa·s; an actual extract density of at least 2.6°P; and an alcohol content of at least 1% by volume. The present patent application further describes a method for obtaining a beverage comprising the steps of: / CCfr ίη / ΖΖΠΖ / Ε / ΥΙΛΙ a. provide a first single-serving container comprising the aforementioned malt-based beverage concentrate; b. provide a second single-serving container containing an ethanol solution having an ethanol concentration of 75% by volume or more; c. provide a source of liquid diluent; d. mix a portion of the diluent source with the contents of the second single-portion container, to obtain an intermediate liquid mixture having an alcohol content of 30% by volume or less; e. Mix the contents of the first single-serving container with this intermediate liquid mixture and potentially an additional amount of the liquid diluent to obtain a beverage. BRIEF DESCRIPTION OF THE INVENTION The inventors have developed a capsule that can be used to prepare a hoppy alcoholic beverage with a head similar to that of regular beer. To prepare this drink, the contents of the capsule are combined with carbonated water and dispensed into, for example, a drinking glass. The capsule of the present invention comprises at least two compartments, including a first compartment and a second compartment; wherein the first compartment comprises 5-30 mL of an aqueous liquid having an ethanol content of 0-10% ABV and comprising 0.1-25% by weight of protein; and wherein the second compartment comprises 5-50 mL of an alcoholic liquid containing 20-99.9% by weight of ethanol, 0-60% by weight of water, and 30-2,000 mg / kg of hop acids selected from iso-alpha acids, hydrogenated iso-alpha acids, hulupones and combinations thereof, and wherein the ethanol and water together constitute at least 80% by weight of the alcoholic liquid. Separating ethanol and hop acids from the other components necessary for preparing a high-quality hoppy alcoholic beverage offers several advantages. Flavor changes due to the formation of ethyl esters (e.g., ethyl acetate) and / or haze formation due to protein and / or saccharide precipitation are avoided. Furthermore, the precipitation of water-poor hop acids is prevented by dissolving these acids in the alcoholic liquid. In other words, by separating water and protein on one hand from ethanol and hop acids on the other, both the aqueous and alcoholic liquids are highly stable. The invention also relates to a process for preparing a single-serving capsule according to the present invention, this process comprising: / CCfr Ln / Zznz / E / YIAI • combine a liquid aqueous composition and a source of a protein foaming agent to produce the aqueous liquid, this source of a protein foaming agent containing, calculated on a dry matter weight basis, at least 3% by weight of protein foaming agent; • combining a liquid alcoholic composition and a hop acid source to produce the liquid alcoholic composition, this liquid alcoholic composition containing at least 30% by weight of ethanol and not more than 60% by weight of water, ethanol and water together constituting at least 80% by weight of the liquid alcoholic composition, this hop acid source containing at least 10% by weight of hop acids selected from iso-alpha acids, hydrogenated iso-alpha acids, hulupones and combinations thereof; • provide a capsule comprising at least two compartments, including a first compartment and a second compartment; • introduce the aqueous liquid into the first compartment of the capsule; • introduce the alcoholic liquid into the second compartment of the capsule; and • close the first and second compartments of the capsule. A good quality alcoholic beverage with a foam height can be prepared using the single-serving capsule of the present invention by: • Insert the single-serving capsule into a beverage preparation device; • release the aqueous fluid from the first compartment; • release the alcoholic liquid from the second compartment; • combine the released aqueous liquid, the released alcoholic liquid, water, and carbon dioxide to produce a hoppy alcoholic beverage; • Dispense the hoppy alcoholic beverage to produce a hoppy alcoholic beverage with a height of foam. BRIEF DESCRIPTION OF THE FIGURES Figure 1 provides a cross-sectional view of a single-portion capsule according to the invention. Figure 2 shows a representation of a beverage preparation device containing a single-serving capsule according to the invention. DETAILED DESCRIPTION OF THE INVENTION Therefore, one aspect of the present invention relates to a single-serving capsule for preparing a hoppy alcoholic beverage with a foam height, this capsule comprising at least two compartments, including a first compartment and a second compartment; / CCfr ίη / ZZΖΠZ / E / YΙΛΙ the first compartment comprising 5-30 mL of an aqueous liquid having an ethanol content of 0-10% ABV and comprising 0.1-25% by weight of protein; the second compartment comprising 5-50 mL of an alcoholic liquid containing 20-99.9% by weight of ethanol, 0-60% by weight of water, and 30-2,000 mg / kg of hop acids selected from iso-alpha acids, hydrogenated iso-alpha acids, hulupones and combinations thereof; wherein the ethanol and water together constitute at least 80% by weight of the alcoholic liquid. The term “capsule”, as used herein, refers to a compartmentalized container suitable for separately retaining the two liquid components according to the invention. The term “single serving,” as used herein, is synonymous with “single serving” or “unit dose” and refers to a capsule comprising sufficient quantities of the aqueous and alcoholic liquids to prepare one serving of reconstituted hoppy alcoholic beverage with a specified head. Typically, one serving of this beverage is in the range of 120 ml to 1000 ml. Preferably, one serving of the beverage is in the range of 180–300 ml. The concentrations of acids as mentioned herein, unless otherwise stated, also include dissolved salts of these acids, as well as dissociated forms of these same acids and salts. The term “iso-alpha acids,” as used herein, refers to substances selected from the isohumulone, isoadhumulone, isocohumulone, preisohumulone, post-isohumulone, and combinations thereof group. The term “iso-alpha acids” encompasses different stereoisomers (cis-iso-alpha acids and trans-iso-alpha acids). Iso-alpha acids are intensely bitter, with an estimated threshold value in water of approximately 6 ppm. The term iso-alpha hydrogenated acids refers to substances selected from dihydro-iso-alpha acids, tetrahydro-iso-alpha acids, hexahydro-iso-alpha acids, and combinations thereof. The term “hulupones”, as used herein, refers to selected substances of cohulupone, n-hulupone, adhulupone, and combinations thereof. Hulupons are oxidation products of hop beta acids. The term “amyl alcohols”, as used herein, refers to alcohols with the formula C5H12O. The concentrations of components in the aqueous or alcoholic liquid can be accurately determined by gas chromatography and / or high-performance liquid chromatography using a calibration curve. The calibration curve is created by preparing a set of standard solutions with known decreasing analyte concentrations. The detector response (e.g., FID, MS, or MS-MS) is measured for each solution. The calibration curve is obtained by plotting the detector responses against the analyte concentrations. The protein content of the aqueous liquid can be adequately determined by the Kjeldahl method as described in EBC method 9.9.1. The single-serve capsule of the present invention may comprise two or more compartments. More preferably, the capsule contains two compartments, one comprising the aqueous liquid, the other comprising the alcoholic liquid. According to a preferred embodiment, the capsule of the present invention comprises a container with at least two compartments separated by a partition wall, including a first compartment containing the aqueous liquid and a second compartment containing the alcoholic liquid, and wherein the compartments are closed, for example, by a sealed sheet or a lid. Preferably, the first compartment of the single-serving capsule contains 7-28 mL, more preferably 10-25 mL, more preferably 15-23 mL of the aqueous liquid. The second compartment of the single-serving capsule preferably contains 7-40 mL, more preferably 9-35 mL, more preferably 10-32 mL of the alcoholic liquid. The combined internal volume of the first and second compartments preferably does not exceed 60 mL, more preferably this volume is in the range of 12-50 mL, even more preferably in the range of 15-45 mL and most preferably this volume does not exceed 40 mL. The aqueous liquid and the alcoholic liquid as defined in the present invention are preferably contained in the capsule in a weight ratio of 6:1 to 1:1, more preferably in a weight ratio of 4:1 to 1.1:1, and more preferably in a weight ratio of 3:1 to 1.2:1. In one embodiment of the present invention, the aqueous liquid contained in the first compartment of the capsule is a composite liquid that has been prepared by mixing a liquid aqueous composition with a protein source and optionally additional ingredients. In another form, the aqueous liquid is a beer concentrate, especially a beer concentrate that has been obtained by removing water and / or ethanol from beer (including non-alcoholic beer) by means of nanofiltration, reverse osmosis, forward osmosis and / or freeze concentration. The aqueous liquid and / or the alcoholic liquid preferably contains a coloring agent selected from yellow, orange, red, brown, and combinations thereof. In a particular preferred embodiment, the aqueous liquid / CCfr Ln / Zznz / E / YIAI contains the coloring agent selected from yellow, orange, and combinations thereof. Preferably, the coloring agent is selected from riboflavin, carotenes, malt extract, curcumin, lutein, carotene, and combinations thereof. More preferably, the coloring agent is malt extract, most preferably caramel malt extract. The aqueous liquid preferably measures 6-79 EBC color units, more preferably 8-57 EBC color units, and most preferably 8-33 EBC color units. The ethanol content of the aqueous liquid preferably does not exceed 8% ABV, more preferably does not exceed 5% ABV, more preferably does not exceed 2% ABV. The pH of the aqueous liquid at 20°C is preferably less than 5.5, more preferably the pH is in the range of 3.0 to 5.0, even more preferably in the range of 3.5 to 4.5 and most preferably in the range of 3.7 to 4.3. In a preferred embodiment, the aqueous liquid contains 50-2,000 mmol / L of at least one acidulant, more preferably 80-1,200 mmol / L % by weight and more preferably 100-1,000 mmol / L. Preferably, at least one acidulant is selected from lactic acid, citric acid, acetic acid, propionic acid, gluconic acid, malic acid, tartaric acid, fumaric acid, succinic acid, adipic acid, fumaric acid, hydrochloric acid, phosphoric acid, salts of these acids, or combinations thereof. More preferably, at least one acidulant is selected from citric acid, gluconic acid, lactic acid, salts of these acids, and combinations thereof. More preferably, at least one acidulant is selected from citric acid, gluconic acid, salts of these acids, and combinations thereof. The capsule of the present invention can be used to prepare a hoppy alcoholic beverage with an attractive foam height. The protein present in the aqueous liquid contributes to the formation of foam height during dispensing of the reconstituted carbonated beverage. The protein further stabilizes the foam height by preventing it from collapsing shortly after the reconstituted carbonated beverage has been dispensed. Preferably, the aqueous liquid contains 0.05-10% by weight of a protein foaming agent, more preferably 0.1-5% by weight, and even more preferably 0.2-3% by weight. Preferably, the protein foaming agent is selected from lipid transfer protein 1 (LTP1), hordein, casein, wheat protein, egg white protein, whey protein, soy protein, pea protein, Z proteins, hydrolysates of these proteins and combinations thereof. In a preferred embodiment, the aqueous liquid comprises a protein foaming agent selected from LTP-1, hordein, protein Z4, protein Z7, and combinations thereof. Even more preferably, the protein foaming agent is selected from LTP-1, protein Z4, protein Z7, and combinations thereof. LTP-1 used according to the present process is preferably obtained from barley. The Z proteins, in particular protein Z4 and protein Z7, are preferably obtained from cereal grain, more preferably from malt, and more preferably from malted barley. According to a preferred embodiment, the protein foaming agent is provided by a malt extract. According to a particularly preferred embodiment, both a coloring agent and the protein foaming agent are provided by one or more malt extracts. Preferably, 20-70% by weight, more preferably 30-65% by weight and more preferably 40-60% by weight of the dry matter in the aqueous liquid is dry matter of malt extract. The aqueous liquid preferably has a water content in the range of 50-98% by weight, more preferably in the range of 60-96% by weight and most preferably in the range of 70-94% by weight. In a preferred embodiment, the aqueous liquid contains 3-50% by weight, more preferably 5-30% by weight and more preferably 6-20% by weight of sugars selected from maltose, sucrose, lactose, glucose, fructose and combinations thereof. The sugars in the aqueous liquid can be adequately provided by a starch hydrolysate, in particular a starch hydrolysate containing appreciable amounts of maltose and / or glucose. Preferably, the aqueous liquid contains maltose in a concentration of 0.5-20% by weight, more preferably 1-18% by weight, even more preferably 2-16% by weight and most preferably 4-15% by weight. Preferably, the aqueous liquid contains glucose in a concentration of 0.5-25% by weight, more preferably 0.8-15% by weight, even more preferably 1.0-12% by weight and most preferably 1.2-10% by weight. The aqueous liquid preferably contains 3–50% by weight, more preferably 6–45% by weight, and most preferably 12–40% by weight of soluble fiber. These soluble fibers are advantageously included in the aqueous liquid because they have a favorable impact on the mouthfeel of the reconstituted beverage. Examples of soluble fibers that may be used include dextrins (including resistant maltodextrins), inulin, and polydextrose. Preferably, the soluble fiber is selected from dextrins and polydextrose. According to a particular preferred embodiment, the soluble fiber used is dextrins having a degree of polymerization of 4–10. / CCfr Ln / Zznz / E / YIAI In a preferred embodiment, the aqueous liquid contains 0.05-1.0% by weight, more preferably 0.1-0.5% by weight and more preferably 0.2-0.4% by weight of a foam stabilizer selected from pectins; alginates; xanthan gum; gellan gum; carboxymethylcellulose; locust bean gum; carrageenans and combinations thereof. According to a particularly preferred embodiment, the aqueous liquid contains 0.05-1.0% by weight, more preferably 0.1-0.5% by weight and more preferably 0.2-0.4% by weight of foam stabilizer selected from pectins; alginates and combinations thereof. The aqueous liquid preferably contains 0-2 mg / L, more preferably 0-1 mg / L and more preferably 0-0.5 mg / L of dissolved carbon dioxide. In view of the poor water solubility of hop acids in water, it is preferred that the aqueous liquid contain 0-100 mg / L, preferably 0-30 mg / L, more preferably 0-10 mg / L of hop acids selected from iso-alpha acids, hydrogenated alpha acids, hulupones and combinations thereof. Iso-alpha acids, as well as hydrogenated alpha acids and oxidized alpha acids (hulupons), contribute to the pleasant bitterness of beer flavor appreciated by consumers. In a preferred embodiment, the alcoholic liquid comprises 10-1,000 mg / L, more preferably 25-500 mg / L, and more preferably 50-200 mg / L of hop acids selected from iso-alpha acids, hydrogenated alpha acids, hulupons, and combinations thereof. In a particularly preferred embodiment, the alcoholic liquid comprises 10-1,000 mg / L, more preferably 25-500 mg / L, more preferably 50-200 mg / L of isoalpha acids. Iso-alpha acids can be adequately supplied by isomerized hop extract. Preferably, the alcoholic liquid contains 10–10,000 mg / L, more preferably 50–2,000 mg / L, and most preferably 250–1,000 mg / L of isomerized hop extract. The alcoholic liquid present in the second compartment of the capsule preferably contains at least 30% by weight of ethanol, more preferably at least 40% by weight of ethanol, even more preferably at least 50% by weight of ethanol, and most preferably at least 60% by weight of ethanol. Together, ethanol and water preferably constitute at least 85% by weight, more preferably 90-99.9% by weight of the alcoholic liquid. The alcoholic liquid preferably contains 10-800 mg / L, more preferably 20-600 mg / L and more preferably 50-400 mg / L of flavor esters selected from ethyl acetate, ethyl hexanoate, ethyl valerate, isoamyl acetate and combinations thereof. / CCfr Ln / Zznz / E / YIAI These flavor esters impart a desirable taste to the reconstituted beverage that is reminiscent of beer. In another preferred embodiment, the alcoholic liquid contains 50-4,000 mg, more preferably 100-3,000 mg, even more preferably 250-2,000 mg of amyl alcohols. The alcoholic liquid used in this capsule may suitably comprise ethanol obtained from the dealcoholization of an alcoholic beverage, preferably from the dealcoholization of beer. Vacuum distillation is commonly used to remove alcohol from beer. The distillate obtained in this way contains ethanol, water, and a range of volatile beer flavor compounds. These distillates can be advantageously applied to the alcoholic liquid in this capsule. The term “vacuum distillation,” as used herein, also encompasses “vacuum evaporation.” Accordingly, in a preferred embodiment, the alcoholic liquid comprises a distillate obtained by the distillation of a beer containing alcohol. More preferably, the alcoholic liquid consists of this distillate or is an aqueous dilution of this distillate. The distillate obtained by distillation dealcoholization usually contains volatile beer-flavored substances such as ethyl acetate, isoamyl acetate, amyl alcohols, phenylethyl alcohol, and phenylethyl acetate. Preferably, the alcoholic liquid comprises, per kg of ethanol, 50-2,000 mg, more preferably 70-1,500 mg, even more preferably 90-1,200 mg and most preferably 100-800 mg of ethyl acetate. Preferably, the alcoholic liquid comprises, per kg of ethanol, 5-200 mg, more preferably 7-150 mg, even more preferably 9-120 mg and most preferably 10-80 mg of isoamyl acetate. In a preferred embodiment, the alcoholic liquid contains, per kg of ethanol, 400-5,000 mg, more preferably 600-4,000 mg, even more preferably 700-3,500 mg and more preferably 800-3,000 mg of amyl alcohols. In another preferred embodiment, the alcoholic liquid contains, per kg of ethanol, 8-240 mg, more preferably 11-170 mg, even more preferably 13-140 mg and most preferably 15-100 mg of phenylethyl alcohol. Preferably, the alcoholic liquid contains, per kg of ethanol, 2-50 mg, more preferably 3-40 mg, even more preferably 3.5-32 mg and most preferably 4-25 mg of phenylethyl acetate. In a preferred embodiment, the alcoholic liquid is prepared by combining an ethanol-containing liquid, preferably an ethanol-containing distillate as described above in / CCfr Ln / Zznz / E / YIAI, with hop acids selected from iso-alpha acids, hydrogenated iso-alpha acids, hulupones, and combinations thereof. Even more preferably, the alcoholic liquid is prepared by combining an ethanol-containing liquid with iso-alpha acids. The iso-alpha acids can be suitably provided in the form of pre-isomerized hop extract. Another aspect of the invention relates to a process for preparing a single-serving capsule according to the present invention, this process comprising: • combining a liquid aqueous composition and a source of a protein foaming agent to produce the aqueous liquid, this source of a protein foaming agent containing, calculated on a dry matter weight basis, at least 3% by weight of protein foaming agent; • combining a liquid alcoholic composition and a hop acid source to produce the liquid alcoholic composition, this liquid alcoholic composition containing at least 30% by weight of ethanol and not more than 60% by weight of water, ethanol and water together constituting at least 80% by weight of the liquid alcoholic composition, this hop acid source containing at least 10% by weight of hop acids selected from iso-alpha acids, hydrogenated iso-alpha acids, hulupones and combinations thereof; • provide a capsule comprising at least two compartments, including a first compartment and a second compartment; • introduce the aqueous liquid into the first compartment of the capsule; • introduce the alcoholic liquid into the second compartment of the capsule; and • close the first and second compartments of the capsule. The protein foaming agent contained in the protein foaming agent source is preferably a protein foaming agent as described above herein. The protein foaming agent source used in the present process preferably contains, calculated on a dry matter weight basis, at least 4% by weight, more preferably at least 5% by weight, and more preferably at least 10% by weight of the protein foaming agent. According to a particularly preferred embodiment, the source of a protein foaming agent employed according to the invention is malt extract. Preferably, the source of a protein agent is a malt extract. The malt extract offers the advantage that, in addition to the protein foaming agent (e.g., LTP-1 protein and / or Z proteins), it can provide color. According to another preferred embodiment, the present process comprises combining a coloring agent with the liquid aqueous composition and / or the liquid alcoholic composition. This coloring agent is selected from riboflavin, carotenes, malt extract, curcumin, lutein, carotene, and combinations thereof. More preferably, the coloring agent is caramel malt extract. The coloring agent is preferably combined with the liquid aqueous composition. Preferably, the process comprises combining the liquid aqueous composition with at least one acidulant selected from lactic acid, citric acid, acetic acid, propionic acid, gluconic acid, malic acid, tartaric acid, fumaric acid, succinic acid, adipic acid, fumaric acid, salts of these acids, or combinations thereof. More preferably, the at least one acidulant is selected from citric acid, gluconic acid, lactic acid, salts of these acids, and combinations thereof. In the present process, the aqueous liquid composition is preferably combined with one or more sugars selected from maltose, sucrose, lactose, glucose, and fructose. More preferably, the aqueous liquid is combined with a hydrolyzed starch component containing, calculated on a dry matter weight basis, at least 5% by weight, more preferably at least 10% by weight, and more preferably 15–100% by weight of maltose and / or glucose. According to another advantageous embodiment of the process, the aqueous liquid composition is combined with a source of soluble fiber. Examples of soluble fibers that may be employed include dextrins (including resistant maltodextrins), inulin, and polydextrose. Preferably, the soluble fiber is selected from dextrins and polydextrose. According to one particular preferred embodiment, the soluble fiber employed is dextrins having a degree of polymerization of 4–10. Preferably, the soluble fiber source contains at least 20% by weight, more preferably at least 40% by weight, and most preferably at least 50% by weight of soluble fiber. The present process preferably comprises combining the aqueous liquid composition with a foam stabilizer selected from pectins, alginates, xanthan gum, gellan gum, carboxymethylcellulose, locust bean gum, carrageenans, and combinations thereof. According to a particularly preferred embodiment, the foam stabilizer is selected from pectins, alginates, and combinations thereof. The hop acid source used in the present process preferably contains at least 15% by weight, more preferably 18-80% by weight, of hop acids selected from 1 / 8-alpha acids, hydrogenated 1 / 8-alpha acids, hulupones, and combinations thereof. More preferably, the hop acid source contains at least 10% by weight, more preferably 15-80% by weight, of 1 / 8-alpha acids. / CCfr Ln / Zznz / E / YIAI The source of hop acids used in the present process is preferably a hop extract, more preferably an isomerized hop extract. According to a particularly preferred embodiment, the liquid alcoholic composition of the present process is obtained from the dealcoholization of an alcoholic beverage, more preferably from the dealcoholization of beer. The liquid alcoholic composition is preferably obtained by dealcoholizing an alcoholic beverage using vacuum distillation. More preferably, the liquid alcoholic composition is obtained by dealcoholizing an alcoholic beer. The liquid alcoholic compositions obtained by dealcoholizing beer, especially when vacuum distillation is used to remove the alcohol, contain appreciable levels of beer flavor esters (in particular, ethyl acetate, ethyl hexanoate, ethyl valerate, and isoamyl acetate) and higher alcohols (in particular, n-propanol, isobutanol, amyl alcohol, isoamyl alcohol, and 2-phenyl ethanol). Yet another aspect of the invention relates to a method for preparing a hoppy alcoholic beverage with a foam height, this method comprising: • insert the single-serving capsule according to the invention into a beverage preparation device; • release the aqueous fluid from the first compartment; • release the alcoholic liquid from the second compartment; • combine the released aqueous liquid, the released alcoholic liquid, water, and carbon dioxide to produce a hoppy alcoholic beverage; • Dispense the hoppy alcoholic beverage to produce a hoppy alcoholic beverage with a height of foam. The release of aqueous fluid and alcoholic fluid can occur simultaneously or sequentially, in any order. The combination of the released aqueous liquid with water may occur, at least partially, within the first capsule compartment, for example, when rinsing the compartment with water. This flush water may already contain carbon dioxide and / or the alcoholic liquid. Similarly, the combination of the released alcoholic liquid with water may occur, at least partially, within the second capsule compartment, for example, when rinsing the compartment with water or with water containing carbon dioxide and / or the aqueous liquid. The combination of aqueous liquid, alcoholic liquid, water, and carbon dioxide can be done in different ways. In a particularly preferred embodiment, the first water and carbon dioxide are mixed to produce carbonated water; a portion of the carbonated water is mixed with the released alcoholic liquid to produce the alcoholic carbonated aqueous liquid; the other portion of the carbonated water is mixed with the released aqueous liquid to produce a diluted carbonated aqueous liquid; and the alcoholic carbonated aqueous liquid and the diluted carbonated aqueous liquid are mixed to produce the hoppy alcoholic beverage. In a further preferred embodiment, water and carbon dioxide are mixed to produce carbonated water, after which the carbonated water is mixed with the released alcoholic liquid to produce the alcoholic carbonated aqueous liquid, which is finally mixed with the released aqueous liquid as defined in the present invention. In another preferred embodiment, the first water and the released alcoholic liquid are mixed to produce a dilute alcoholic liquid, after which carbon dioxide is mixed in to produce an alcoholic carbonated aqueous liquid that is finally mixed with the released aqueous liquid as defined in the present invention. In yet another preferred embodiment, water, carbon dioxide, and the released alcoholic liquid are mixed in a single step to produce an alcoholic carbonated aqueous liquid, followed by mixing of the released aqueous liquid. Preferably, carbonated water contains 1-8 g / L, more preferably 2-7 g / L of dissolved carbon dioxide. In a preferred embodiment, the beverage preparation device comprises a water reservoir and a reservoir that retains pressurized carbon dioxide. Figure 1 shows a single-portion capsule (10) comprising a body (20) made of aluminum sheet, which has the general shape of a truncated cone with a rim (30) at its base. The body (20) terminates at its smaller end with an obtuse cone (21). The rim (30) is formed by pinching the body around a sheet (40) and the capsule (10) is sealed by heat-sealing the body (20) and the sheet (40). The sheet (40) can be made of aluminum. The capsule (10) comprises a first compartment (50) and a second compartment (60), separated by a dividing wall (70). The larger first compartment (50) retains an aqueous liquid as defined in the present invention (51), while the smaller second compartment (60) retains an alcoholic liquid (61). The obtuse cone (21) comprises weakened recesses (22) in the part defining the first compartment (50). The obtuse cone (21) further contains weakened recesses (23) in the part defining the second compartment (60). The sheet (40) comprises a number of weakened sections (41) in the part that defines the first compartment (50) and weakened recesses (42) in the part that defines the second compartment (60). / CCfr Ln / Zznz / E / YIAI During use, both the weakened recesses (22) and (23) are perforated by tubular inlets, and the weakened sections (41) and (42) in the sheet are penetrated by tubular outlets. Then, carbonated water injected into the first compartment (50) and the second compartment (60) through the tubular inlets washes the aqueous liquid (51) from the first compartment (50) and the alcoholic liquid (61) from the second compartment (60) through the outlet channels. Figure 2 shows a representation of a device (10) for preparing a hoppy alcoholic beverage with a foam height using a single-serving capsule as depicted in Figure 1. The device includes a housing (11) that accommodates the mechanical and electronic components of the device (10). The housing (11) can be made of plastic and / or metal. The device (10) comprises a power supply (20) and a control system (30) operable for activating the device and its control functions (e.g., the volume, temperature, and / or alcohol content of the dispensed hoppy alcoholic beverage). An empty glass (40) placed beneath the dispensing unit (50) is also shown. The device (10) also includes a water source in the form of a water tap (60) and a cooling unit (70). The device (10) further comprises a cylinder (80) containing pressurized carbon dioxide, a carbonation unit (90), a mixing unit (100), and a receptacle (110) for receiving a two-compartment single-serving capsule (120). The single-serving capsule (120) comprises a first compartment (121) containing an aqueous liquid as defined in the invention (123) and a second compartment (122) containing an alcoholic liquid (124). The compartments (121, 122) are sealed by a foil (125). The device (10) comprises means for opening both the upper and lower ends of the first and second compartments (121,122) of the single-portion capsule (120). During use, a consumer can place the single-serve capsule (120) into the receptacle (110) of the device (10). The consumer can then activate the device (10) using the control system (30) and wait for the dispensing of the hoppy alcoholic beverage from the dispensing unit (50) into the glass (40) to produce a hoppy alcoholic beverage (41) with foam height (42). After activation of the device (10), tap water (60) and pressurized carbon dioxide from the cylinder (80) are dispensed into the carbonation unit (90). During its passage through the carbonation unit (90), the water is cooled by the cooling unit (70). Once the appropriate amounts of water and carbon dioxide have been mixed in the carbonation unit (90), the carbonated water is released from the unit (90) and flows through the single-serve capsule (120) to the mixing unit (100). The carbonated water stream from the carbonation unit (90) follows two different flow paths: one flow path passes through the first compartment (121) of the single-serve capsule (120), while the other flow path passes through the second compartment (123) of the single-serve capsule (120). As it passes through the single-serve capsule (120), the carbonated water washes over the aqueous liquid (123) and the alcoholic liquid (124) in the mixing unit (100). In the mixing unit (100), the carbonated water, the washed aqueous liquid, and the washed alcoholic liquid are thoroughly mixed to produce a hoppy alcoholic beverage. Then alcoholic beverage beer is released from the mixing unit (100) through the dispensing unit (50) into a glass (40) under the formation of a foam height. It shall be understood that in the device of figure 1 the single portion capsule (120) can be replaced by two separate capsules, one containing the aqueous liquid, the other containing the alcoholic liquid. The invention is further illustrated by the following non-limiting examples. EXAMPLES Example 1 A single-serving capsule was prepared according to the invention using a capsule comprising two compartments. One compartment (compartment A) has an internal volume of 18 mL, the other compartment (compartment B) has an internal volume of 50 mL. An aqueous liquid was prepared based on the recipe shown in Table 1. Table 1 / CCfr ίη / ΖΖΠΖ / Ε / ΥΙΛΙ g / L Malt extract1 333 Soluble fibers2 250 Water Remainder 165% by weight of dry matter, 24.3% by weight of sugars (including 19% by weight of maltose and 3.3% by weight of glucose), 2.3% by weight of protein, 150 EBC2 50 / 50 (w / w) blend of LitesseMR Ultra Solution - 70% by weight of solids (Danisco UK Limited) and Fibersol-2MR (ADM / Matsutani LLC) An alcoholic liquid containing 21.6% ABW ethanol was prepared based on the recipe shown in Table 2. Table 2 / ccfr Ln / zznz / E / YiAi mg / L α-so acids 1 100 Beer flavor esters 82 Higher alcohols 444 Dealcoholization distillate 2 Remainder 1provided by isomerized hop extract containing 22.5% by weight of iso-alpha acids 2obtained by vacuum distillation of an alcoholic lager beer (containing 21.6% by weight (27.4% ABV) of ethanol, 60 ppm of ethyl acetate; 5 ppm of isoamyl acetate and 400 ppm of higher alcohols) 15 mL of the aqueous liquid were introduced into compartment A of the capsule. In addition, 45 mL of the alcoholic liquid were introduced into compartment B. After filling, the compartments were sealed with a flexible film. The contents of the single-serving capsule were mixed with carbonated water (6.5 g / L of dissolved carbon dioxide) to reach a total volume of 250 mL. The resulting beverage had a stable head. It was evaluated by a trained beer tasting panel and was well received. There was some variation in perception, but all agreed that the beverage tasted similar to that of regular beer. The main difference from regular beer noted by the panel was the beverage's pale color. Example 2 A single-serving capsule according to the invention is prepared using a capsule comprising two compartments. One compartment (compartment A) has an internal volume of 12 mL, the other compartment (compartment B) has an internal volume of 33 mL. An aqueous liquid is prepared based on the recipe shown in Table 3. Table 3 g / L Malt extract1 500 Soluble fibers2 375 Malt extract3 0.41 Propylene glycol alginate 0.1 Lactic acid 11.4 Water Remainder 165% by weight dry matter, 24.3% by weight sugars (including 19% by weight maltose and 3.3% by weight glucose), 2.3% by weight protein, 150 EBC2 50 / 50 (w / w) blend of LitesseMR Ultra, Solution Grades (Danisco UK Limited) and Fibersol-2MR (ADM / Matsutani LLC) 33.2% by weight sugars, 1.5% by weight protein, 15,500 EBC An alcoholic liquid containing 33.1% ABW ethanol is prepared based on the recipe shown in Table 4. Table 4 / crn Ln / zznz / E / YiAi mg / L Iso-alpha acids 1 150 Beer flavor esters 125 Higher alcohols 664 Dealcoholization distillate 2 Remainder 1provided by isomerized hop extract containing 22.5% by weight of iso-alpha acids 2obtained by vacuum distillation of an alcoholic lager beer (containing 33.1% by weight (42% ABV) of ethanol, 100 ppm of ethyl acetate; 11 ppm of isoamyl acetate and 630 ppm of higher alcohols). 10 mL of the aqueous liquid are introduced into compartment A of the capsule. In addition, 30 mL of the alcoholic liquid are introduced into compartment B. After filling, the compartments are sealed with a flexible film. The contents of the single-serving capsule are mixed with carbonated water (6 g / L of dissolved carbon dioxide) to reach a total volume of 250 mL. The beverage obtained in this way is similar to a Plissen-style beer in terms of taste and appearance. Example 3 An unhopped lager (containing 5% ABV) was dealcoholized by vacuum distillation (Schmidt-Bretten, Bretten, Germany - feed: 5 hL / hr; steam mass flow rate: 100 kg / h; outlet pressure: 3.5 bar; vacuum setting: 90 mbar; outlet temperature: 3°C). The resulting dealcoholized beer had an ethanol content of 0.01% ABV. The distillate produced during dealcoholization was recovered and analyzed. The results are shown in Table 5. Table 5 Ethanol 60% by weight Ethyl acetate 50.2 mg / L Isoamyl acetate 4.56 mg / L Amyl alcohols 206 mg / L Phenylethyl alcohol 5.09 mg / L Phenylethyl acetate 2.77 mg / L The dealcoiled, unhopped beer was concentrated by nanofiltration using the following setup: Nanofiltration Membrane / CCfr Ln / Zznz / E / YIAI Configuration Type: Spiral wound Membrane Polymer: Composite product polyamide Brine separator material: Polypropylene Specifications Permeate product flow: • MgSO4: 7.6 m3 / d • NaCl: 9.5 m3 / d Stabilized salt rejection1: • MgSO4: >97% (2000 ppm, 4.8 bar, 25 °C, 15% recovery, pH 6.5) • NaCl: 89-95% (500 ppm, 4.8 bar, 25 °C, 15% recovery, pH 7.0) Nominal membrane area: 7.9 m2 1Equivalent to an MW cutoff value of approximately 200 Da Configuration ►Toj*AhdJ< ' ..............-jD-ÍCn) __] O > _ , ................... Yo BC (P ; Permeate product (FJ Feed kCr]z Concentrate A (total length) = 1016 mm B (ATD diameter) = 100.3 mm C (connection diameter) = 19.1 mm Df (core tube extension - feed side) From (core tube extension - conc side) = 26.7 mm 26.7 mm Maximum Operating Limits • Pressure: 80 bar • Temperature: 28°C • Pressure Drop: 0.7 bar • Feed Flow Rate: 3.6 m³ / h • Chlorine Concentration: <0.1 ppm • Feed Water SDI (15 min.): 5.0 • Feed Water Turbidity: 1.0 NTU • Feed Water pH: 3.0-10.0 • Maximum Concentrate to Permeate Flow Ratio for any Element: 5:1 Filtration run The beer was circulated by a piston pump. This pump has a capacity of 1 m³ / h and a maximum discharge pressure of 20–80 bar. The test unit was limited to approximately 30 bar and protected by an overpressure relief valve with a set point of 40 bar. The initial production of permeate product began at a pressure of around 15 bar (osmotic pressure). A total of 100 liters of beer were filtered, producing 84.6 liters of permeate and 16.1 liters of liquid concentrate. Therefore, the concentration factor achieved was 100 / 15.4 = 6.5. The composition of the beer concentrate obtained in this way is shown in Table 6. / crn ίη / ζζηζ / Ε / γΐΛΐ Table 6 Acetic acid 310 mg / L Riboflavin 890 pg / L Oleic acid 1040 pg / L Linoleic acid 980 pg / L Alpha-linolenic acid 630 pg / L Free amino nitrogen 310 mg / L Maltose 1.1 g / L Maltotriose 7.0 g / L Maltotetraose 22 g / L The liquid beer concentrate had a surface tension of 46 mN / m. Comparative Example A A commercial hop lager beer having an alcohol content of 5.0% ABV and an iso-alpha acid content of 19 mg / L was concentrated by nanofiltration using the same setup as in Example 3. The initial production of permeate product began at a pressure of approximately 4 bar (osmotic pressure). A total of 200 liters of beer were filtered, yielding 172.3 liters of permeate and 27.7 liters of concentrate. Therefore, the concentration factor achieved was 200 / 27.7 = 7.2. The hoppy alcoholic beer concentrate obtained in this way was cloudy, had an ethanol content of 4.71% ABV, a specific gravity of 1.8298 (20°P), and a surface tension of 39.7 mN / m. The concentrate contained 78.7 mg / L of iso-alpha acids, meaning that 42.5% of the iso-alpha acids were lost during the nanofiltration step. Example 4 The liquid beer concentrate from comparative example A and the beer concentrate from example 3 were standardized to a concentration factor of 6 (i.e., 6 times more concentrated than the original unhopped lager beer) by the addition of a diluent as shown in Table 7. / crn Ln / zznz / E / YiAi Table 7 Sample Liquid beer concentrate Diluent A Comparative example A Demineralized water B Example 3 Demineralized water C Example 3 Demineralized water and ethanol to produce a concentrate containing 5% ABV of ethanol D Example 3 Demineralized water and pre-isomerized hop extract, to produce a concentrate containing 120 mg / L of iso-alpha acids After preparation, the samples were kept at 0 °C for 7 days. The turbidity of the samples was then measured at 0 °C (in triplicate) at scattering angles of 25° and 90°, using a Sigrist photometer. The average results are shown in Table 8, in EBC units. Table 8 Turbidity Sample 90° 25° A >100 > 100 B 46.07 65.93 C 42.97 62.17 D 62.80 78.33 These results showed that the introduction of iso-alpha acids into the beer concentrate caused mist formation, probably as a result of the precipitation of iso-alpha acids. Aliquots of samples A, B, C, and D are stored at 30 °C and 40 °C for 3 months during which the concentration levels of ethyl esters, turbidity, and color are monitored. Samples B and D were found to be more stable than the other samples. Unlike samples B and D, samples A and C showed significant formation of ethyl esters during the storage period. Example 5 A dealcoholized non-hopped lager and an alcoholic distillate are produced in the same way as in example 3. The dealcoholized, non-hopped beer is concentrated by reverse osmosis using a flat-sheet reverse osmosis filtration membrane made of a thin-film composite product comprising a polyamide membrane layer on a polyester (PET) support material (RO90, ex Alfa Laval, operating pressure 5-25 bar). This membrane has a rejection of at least 90%, measured at 2000 ppm NaCl, at 9 bar and 25°C. Example 6 A single-serving capsule according to the invention is prepared using a capsule comprising two compartments. One compartment (compartment A) has an internal volume of 20 mL, the other compartment (compartment B) has an internal volume of 35 mL. The alcoholic distillate from example 3 is mixed with a pre-isomerized hop extract to produce a solution containing 210 mg / L of iso-alpha acids. 18 mL of the concentrated alcoholic liquid containing hop extract are introduced into compartment A of the capsule. In addition, 32 mL of the liquid beer concentrate from example 3 are introduced into compartment B. After filling, the compartments are sealed with a flexible film. Example 7 A dealcoholized, non-hopped lager beer was concentrated by nanofiltration as described in Example 3. The beer concentrate obtained in this way (concentrate A) was subjected to accelerated storage at 30°C and 40°C. The same storage tests were performed with the same concentrate after ethanol had been added at a concentration of 5% by weight (concentrate B). / CCfr ίη / ΖΖΠΖ / Ε / ΥΙΛΙ Before the storage test and after 3 months of storage, the concentration levels of a quantity of beer flavoring substances were determined. The results of these analyses are shown in Table 9. / CCfr Ln / Zznz / E / YIAI Table 9 Samples Microgram / L Octanoate Ethyl acetate Ethyl propionate Ethyl butanoate 3-methyl-phenylethyl acetate Ethyl acetate Ethyl butanoate A Fresh 30°C 40°C 0 640 4.7 7.9 0.1 0.0 0 400 4.2 6.2 0.1 0.0 0 320 4.7 6.0 0.2 0.0 B Fresh 30°C 40°C 0 720 20 52 1.2 0.0 4600 2040 74 163 9.7 0.2 4320 4040 152 230 25 0.5 Example 8 A lager beer having an ethanol content of 5% by volume was concentrated by nanofiltration as described in comparative example A. Accelerated storage tests were performed with this concentrate (concentrate A) at 30°C and 40°C. Before the storage test and after 3 months, the concentration levels of a quantity of beer flavoring substances were determined. The results of these analyses are shown in Table 10. Table 10 Samples Microgram / L Ethyl 3-methylbutanoate Ethyl phenylacetate Fresh 8.5 0.0 30°C 23 0.2 40°C 47 0.4 Example 9 Two reconstituted beers were prepared by mixing 32 mL of beer concentrate, with 11.4 mL of alcoholic liquid and 205 mL of carbonated water (Royal ClubMR soda, Netherlands). The compositions of the beer concentrates and alcoholic liquids used in the preparation of reconstituted beers are shown in Table 11. Table 11 / crn ίη / ζζηζ / Ε / γΐΛΐ Reconstituted Beer A Reconstituted Beer B Beer Concentrate Beer Concentrate from Example 1 Beer Concentrate from Example 1, containing 6.56 mg of iso-alpha acids per mL Alcoholic Liquid Ethanol (95%), containing 18.42 mg of iso-alpha acids per mL 95% Ethanol Reconstituted beer A was completely clear, had a good head, and a pleasant bitter taste. Reconstituted beer B contained some sediment.

Claims

1. A single-serving capsule for preparing a hoppy alcoholic beverage with a foam height, this capsule being characterized in that it comprises at least two compartments, including a first compartment and a second compartment; the first compartment comprising 5-30 mL of an aqueous liquid having an ethanol content of 0-10% ABV and comprising 0.1-25% by weight of protein; the second compartment comprising 5-50 mL of an alcoholic liquid containing 20-99.9% by weight of ethanol, 0-60% by weight of water, and 50-2,000 mg / kg of hop acids selected from 1 / 2-alpha acids, hydrogenated 1 / 2-alpha acids, hulupones and combinations thereof; wherein the ethanol and water together constitute at least 80% by weight of the alcoholic liquid.

2. Single-serving capsule according to claim 1, characterized in that the aqueous liquid and / or the alcoholic liquid contains a coloring agent selected from yellow dye, orange dye, red dye, brown dye and combinations thereof.

3. Single-serving capsule according to claim 2, characterized in that the coloring agent is selected from riboflavin; carotenes; caramel; malt extract; curcumin; lutein; carbamin; and combinations thereof.

4. Single-portion capsule according to any of the preceding claims, characterized in that the aqueous liquid measures 6-79 EBC color units.

5. Single-serving capsule according to any of the preceding claims, characterized in that the aqueous liquid has a pH of less than 5.

5.

6. Single-serving capsule according to any of the preceding claims, characterized in that the aqueous liquid contains 50-2,000 mmol / L of acidulant selected from lactic acid; citric acid; acetic acid; propionic acid; gluconic acid; malic acid; tartaric acid; fumaric acid; succinic acid; adipic acid; fumaric acid, hydrochloric acid, phosphoric acid, salts of these acids; and combinations thereof.

7. Single-serving capsule according to any of the preceding claims, characterized in that the aqueous liquid contains 0.05-10% by weight of a protein foaming agent.

8. Single-serving capsule according to claim 7, characterized in that the protein foaming agent is selected from LTP1, hordein, casein, wheat protein, egg white protein, whey protein, soy protein, pea protein, Z proteins, hydrolysates of these proteins and combinations thereof.

9. Single-serving capsule according to any of the preceding claims, characterized in that the aqueous liquid contains 3-50% by weight of sugars selected from maltose; sucrose; lactose; glucose; fructose; and combinations thereof.

10. Single-serving capsule according to claim 9, characterized in that the aqueous liquid contains 3-50% by weight of soluble fiber.

11. Single-serving capsule according to any of the preceding claims, characterized in that the aqueous liquid contains 0.05-1.0% by weight of foam stabilizer selected from pectins; alginates; xanthan gum; gellan gum; carboxymethylcellulose; locust bean gum; carrageenans and combinations thereof.

12. Single-serving capsule according to any of the preceding claims, characterized in that the alcoholic liquid contains 10-800 mg / L of beer flavor esters selected from ethyl acetate; ethyl hexanoate; ethyl valerate; isoamyl acetate; and combinations thereof.

13. Single-serving capsule according to any of the preceding claims, characterized in that the combined internal volume of the first and second compartments does not exceed 60 mL.

14. A process for preparing a single-serving capsule according to any of the preceding claims, the process being characterized in that it comprises: • combining a liquid aqueous composition and a source of a protein foaming agent to produce the aqueous liquid, this source of a protein foaming agent containing, calculated by weight or dry matter, at least 3% by weight of protein foaming agent; • combining a liquid alcoholic composition and a source of hop acids to produce the alcoholic liquid, this liquid alcoholic composition containing at least 30% by weight of ethanol and not more than 60% by weight of water, ethanol and water together constituting at least 80% by weight of the liquid alcoholic composition, this source of hop acids containing at least 10% by weight of hop acids selected from iso-alpha acids, hydrogenated iso-alpha acids, hulupones, and combinations thereof;• provide a capsule comprising at least two compartments, including a first compartment and a second compartment; • introduce the aqueous liquid into the first compartment of the capsule; • introduce the alcoholic liquid into the second compartment of the capsule; and • close the first and second compartments of the capsule. / CCfr Ln / Zznz / E / YIAI; 15. A method for preparing a hoppy alcoholic beverage with a foam height, the method being characterized in that it comprises: • introducing the single-serving capsule according to any of claims 1-13 into a beverage preparation device; • releasing the aqueous liquid from the first compartment; • releasing the alcoholic liquid from the second compartment; • combining the released aqueous liquid, the released alcoholic liquid, water, and carbon dioxide to produce a hoppy alcoholic beverage; • dispensing the hoppy alcoholic beverage to produce a hoppy alcoholic beverage with a foam height.