How to make alcohol-free beer

Abstract

The present invention relates to a method for producing alcohol-free beer, comprising the steps of: providing a vessel containing wort; inoculating the wort with yeast, whereby the yeast forms a sedimentary layer at the bottom of the vessel or a floating layer below the surface of the wort; fermenting the inoculated wort at a temperature of −3 to 5° C. for at least 8 hours to produce a fermented wort; separating the fermented wort from the yeast to produce alcohol-free beer; and (a) applying one or more pitchings of additional yeast to the inoculated wort during fermentation; or (b) applying one or more breaks in the yeast layer during fermentation; or (c) applying at least 3×10 6 pitches of additional yeast per mL of wort at the beginning of fermentation. 6 The method of the present invention provides the advantage that an alcohol-free beer having substantially reduced undesirable "wort" flavor notes is obtained.

Description

[Technical field]

[0001] The present invention relates to a method for producing alcohol-free beer using so-called "cold contact fermentation". More particularly, the present invention provides such a method for producing alcohol-free beer with substantially reduced undesirable "worty" flavor notes.

[0002] The invention also relates to the alcohol-free beer obtainable by such a process. [Background technology]

[0003] Beer is a widely popular beverage consumed worldwide. In recent years, the beer market has shown a significant increase in the consumption of alcohol-free beer. This increase has been driven by health and safety concerns and facilitated by technological innovations that have substantially improved the quality of alcohol-free beer.

[0004] Alcohol-free beer is produced by two basic processes: the traditional brewing process is followed by the application of alcohol removal by techniques such as reverse osmosis, dialysis or evaporation. Another approach aims at the reduction of alcohol formation during fermentation by contacting the boiled wort with yeast under conditions that minimize the fermentable production of alcohol. This type of process is commonly called "restricted alcoholic fermentation".

[0005] Cold contact fermentation (or cold contact process) is a form of limited alcoholic fermentation using a combination of low fermentation temperature and extended fermentation contact time. Alcohol-free beers produced using cold contact fermentation usually have off-flavor notes commonly referred to as "worty". These worty flavor notes are due to aldehydes formed during wort boiling, specifically methional (3-methylthiopropionaldehyde), 3-methylbutanal, 2-methylbutanal and 2-methylpropanal.

[0006] Methional is formed by the interaction of α-dicarbonyl compounds (intermediates in the Maillard reaction) with methionine via the Strecker degradation reaction. Similarly, 3-methylbutanal, 2-methylbutanal, and 2-methylpropanal are formed by the interaction of α-dicarbonyl compounds with leucine, isoleucine, and valine, respectively. Because these aldehydes are formed via the Strecker degradation reaction, they are sometimes called "Strecker aldehydes."

[0007] In alcohol-free beers produced by cold contact fermentation, the contribution of the aforementioned wort flavor substances to the overall flavor of the beer is very pronounced. This is partly due to the fact that the concentration of these flavor substances in such alcohol-free beers is higher than in alcoholic beers. Furthermore, the absence of alcohol in alcohol-free beers increases the intensity with which these flavors are perceived by the consumer.

[0008] Gernat et al. (Aldehydes as Wort Off-Flavours in Alcohol-Free Beers-Origin and Control, Food and Bioprocess Technology (2019), 13(2), 195-216.) discuss different techniques to reduce the aldehyde content of alcohol-free beer. These techniques are: · Adsorptive removal using various adsorbent materials; · Separation by extraction; Removal by pervaporation; Removal during dealcoholization; · Reduction of aldehydes during low-temperature contact fermentation; Includes.

[0009] Perpete et al. (How to improve the enzymatic worty flavour reduction in a cold contact fermentation, Food Chemistry (2000), 70, 457-462) reported that the enzymatic removal of Strecker aldehyde by the brewer's yeast, Saccharomyces cerevisiae, is always limited to 60-85% of the initial concentration under any fermentation conditions. According to the authors, this asymptotic reduction pattern causes residual concentrations that give alcohol-free beers a known unpleasant worty flavour. It has been shown that low-energy binding to flavonoids prevents a more complete enzymatic reduction in cold contact fermentation processes.

[0010] Chandrasekhar et al. (Production of Low Alcohol Beer and Alcohol-free Beer using a Combination of High Temperature Mashing and Cold Contact Fermentation, FERMENT, INSTITUTE OF BREWING, GB, vol. 7, no. 4, 1 January 1994, pages 241-244) describe a study investigating the effect of mashing temperature on the quality of low alcohol beer produced by cold contact fermentation. In one of the experiments, a fermenter set up with carbon dioxide percolation was used.

[0011] US Patent Application Publication No. 2013 / 0280399 describes a method for producing an alcohol-free beer-like malt beverage that involves reducing wort-derived off-flavors by adding terpenes, such as terpinolene.

[0012] WO 2020 / 055233 describes a process for producing a non-alcoholic fermented beer having an alcohol content of less than 1.0% ABV, the process being characterized in that the fermentation produces a non-alcoholic fermented wort or the fermentation produces an alcoholic fermented wort, which is subsequently de-alcoholized to produce a non-alcoholic fermented wort or a non-alcoholic beer; and contacting the heated wort, the non-alcoholic fermented wort and / or the non-alcoholic beer with a hydrophobic silicate-based molecular sieve containing SiO2 and Al2O3 in a molar ratio of at least 15. Summary of the Invention [Means for solving the problem]

[0013] The inventors have surprisingly found that in low-temperature contact fermentation, the concentration of Strecker aldehyde is very effective: (a) pitching additional yeast into the wort during fermentation; or (b) Breaking the yeast layer during fermentation by sparging, recirculation or mechanical action; or (c) inoculating the wort with a significant amount of yeast; It has been found that the ion exchange coefficient can be reduced by

[0014] Although the inventors are not bound by theory, it is believed that the ability of yeast to remove Strecker aldehyde during cold contact fermentation is limited due to the fact that during fermentation, yeast cells are contained in a quiescent layer that forms at the bottom of the fermenter or below the surface of the wort. The inventors believe that if yeast cells are further removed from the interface between the yeast layer and the wort, there may be fewer yeast cells that can contribute to the removal of Strecker aldehyde. Furthermore, it is believed that the ability of yeast cells to remove Strecker aldehyde is limited. As a result, only a portion of the ability of yeast to remove Strecker aldehyde is utilized during cold contact fermentation. Once the yeast cells close to the interface reach the limit of their removal ability, no further reduction of Strecker aldehyde is achieved.

[0015] The inventors have found that the ability of yeast to remove Strecker aldehyde during cold contact fermentation can be substantially increased by pitching additional yeast during fermentation or by breaking up the yeast layer during fermentation by sparging, recirculating or mechanical action. A very large inoculum of yeast has also been found to increase the removal of Strecker aldehyde.

[0016] The present invention therefore relates to a method for producing an alcohol-free beer, comprising the steps of: Providing a vessel containing at least 10 hL of wort having a specific gravity of 5 to 25 ° P (Plateau); At least 10 5 The wort is inoculated with cells / mL of yeast, and the yeast forms a settled layer at the bottom of the vessel or a floating layer below the surface of the wort; Fermenting the inoculated wort for at least 8 hours at a temperature between -3 and 5°C to produce a fermented wort; · Separation of the fermented wort from the yeast to produce alcohol-free beer; Including, (a) applying one or more pitches of additional yeast to the inoculated wort during fermentation, said one or more pitches being 10 or more per mL of wort; 5 ~5×10 6 providing a dose of yeast cells, and wherein each of said one or more pitchings is applied at least one hour after inoculation; or (b) one or more disruptions of the yeast layer are applied during fermentation, with at least one of the one or more disruptions being applied at least one hour after inoculation or continued until at least one hour after inoculation; or (c) At the beginning of fermentation, at least 3 × 10 6 Inoculating the wort with yeast cells; and The method does not include the addition of a Strecker aldehyde selected from 2-methylbutanal, 3-methylbutanal, and methional.

[0017] There is also provided an alcohol-free beer having an ethanol content of less than 0.5% by volume, said alcohol-free beer comprising: · 20-90 g / L of fermentable sugars selected from glucose, maltose, maltotriose and combinations thereof; 2-Methylbutanal 0-6μg / L; 3-Methylbutanal 0-14μg / L 2-Methylpropanal 0-12 μg / L; Methional 0-6μg / L; Phenylacetaldehyde 8-100 μg / L; and Furfural 30-500μg / L; Including, a combination of 2-methylbutanal, 3-methylbutanal, 2-methylpropanal, and methional are present at a combined concentration of X μg / L; phenylacetaldehyde is present at a concentration of Y μg / L, and furfural is present at a concentration of Z μg / L; and X:Y≦1:2; and / or X:Z≦1:20. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] A first aspect of the present invention relates to a method for producing an alcohol-free beer, said method comprising: Providing a vessel containing at least 10 hL of wort having a specific gravity between 5 and 25 ° P; At least 10 5 The wort is inoculated with cells / mL of yeast, and the yeast forms a settled layer at the bottom of the vessel or a floating layer below the surface of the wort; Fermenting the inoculated wort for at least 8 hours at a temperature between -3 and 5°C to produce a fermented wort; · Separation of the fermented wort from the yeast to produce alcohol-free beer; Including, (a) applying one or more pitches of additional yeast to the inoculated wort during fermentation, each of said one or more pitches providing 10 5 ~5×10 6providing a dose of yeast cells, and one of said one or more pitchings is applied at least one hour after inoculation; or (b) one or more disruptions of the yeast layer are applied during fermentation, with at least one of the one or more disruptions being applied at least one hour after inoculation or continued until at least one hour after inoculation; or (c) At the beginning of fermentation, at least 3 × 10 6 Inoculating the wort with yeast cells; and The method does not include the addition of a Strecker aldehyde selected from 2-methylbutanal, 3-methylbutanal, and methional.

[0019] As used herein, the term "or" is to be interpreted as "and / or" unless otherwise indicated.

[0020] The terms "a" or "a type," as used herein, unless otherwise indicated, are defined as "at least one (a type)."

[0021] The wort used in the method of the present invention preferably has a specific gravity of 8 to 22°P, more preferably 10 to 20°P.

[0022] At the time of inoculation, the wort preferably contains at least 20 μg / L, more preferably at least 30 μg / L, and most preferably 50-300 μg / L of 2-methylbutanal.

[0023] At the time of inoculation, the wort preferably contains at least 40 μg / L, more preferably at least 60 μg / L, and most preferably 100-600 μg / L of 3-methylbutanal.

[0024] At the time of inoculation, the wort preferably contains at least 20 μg / L, more preferably at least 30 μg / L, and most preferably 80-600 μg / L of 2-methylpropanal.

[0025] Methional is contained in the wort at the time of inoculation at a concentration of at least 16 μg / L, more preferably at least 40 μg / L, and most preferably 60 to 300 μg / L.

[0026] The wort inoculated in the method of the present invention is preferably a hop wort containing at least 1.0 mg / L of iso-α-acids, more preferably at least 1.5 mg / L and most preferably 2.0-80 mg / L of iso-α-acids selected from isohumulone, isoadhumulone, isocohumulone, reduced versions of these iso-α-acids and combinations thereof. The reduced versions of iso-α-acids are tetrahydroiso-α-acids and hexahydroiso-α-acids.

[0027] The method of the present invention can be suitably operated on an industrial scale. Preferably, the amount of wort contained in the vessel is at least 20 hL, most preferably 30 to 5,000 hL.

[0028] The yeast used in the method of the present invention is preferably selected from Saccharomyces pastorianus, Saccharomyces uvarum, Saccharomyces cerevisiae, and combinations thereof. Most preferably, the yeast is Saccharomyces pastorianus.

[0029] The method of the invention can be carried out either with bottom-fermenting yeast, which forms a yeast layer at the bottom of the fermenter, or with top-fermenting yeast, which forms a floating layer at the surface of the wort. Preferably, the yeast is a bottom-fermenting yeast, which allows the yeast to form a layer at the bottom of the fermenter after inoculation.

[0030] The yeast may be inoculated into the wort in the form of dry yeast or wet yeast. Preferably, the yeast used in this method is wet yeast. The wet yeast used preferably has an ethanol content of 0 to 3% by weight, more preferably 0 to 1% by weight.

[0031] In a preferred embodiment, the yeast used for inoculation is obtained from the production of alcoholic beer and the ethanol is removed therefrom by washing prior to inoculation.

[0032] The yeast layer formed after inoculation preferably has a thickness of at least 0.1 mm, more preferably at least 0.5 mm, most preferably between 1 and 40 mm.

[0033] As a precaution, the method of the present invention includes additional pitching of yeast or disruption of the yeast layer, preferably at least 3×10 5 cells / mL, more preferably 10 6 ~10 7 cells / mL to inoculate the wort.

[0034] The method of the present invention preferably employs a fermentation period of at least 16 hours, more preferably from 20 to 120 hours, and most preferably from 24 to 72 hours.

[0035] In the method of the present invention, the inoculated wort is fermented preferably at a temperature of -2 to 4°C for at least 16 hours, more preferably 20 to 120 hours, and most preferably 24 to 72 hours.

[0036] According to a particularly preferred embodiment, the inoculated wort is fermented at a temperature of -1 to 2°C for at least 16 hours, more preferably 20 to 120 hours, most preferably 24 to 72 hours.

[0037] The yeast may be separated from the fermented wort using solid-liquid separation techniques known in the art. Preferably, the yeast is separated from the fermented wort by filtration, centrifugation or decanting.

[0038] In embodiments of the method of the invention that include the application of one or more pitches of additional yeast during fermentation, the method preferably comprises applying at least 10 5 ~5×10 6 More preferably, the method includes 10 to 100 pitchings, providing a dose of yeast cells / mL wort. 5 ~5×10 6 The method includes 2 to 50 pitchings, providing a dose of yeast cells / mL wort. Most preferably, the method includes 10 5 ~5×10 6 Contains 3-20 pitchings, providing a dose of yeast cells / mL wort.

[0039] The time interval between inoculation and the first of the pitching(s) and between successive additional pitchings is preferably in the range of 0.5 to 50 hours, more preferably 1 to 30 hours.

[0040] In embodiments of the methods of the invention that include one or more disruptions of the yeast layer, the one or more disruptions of the yeast layer are preferably accomplished by sparging, recirculation or mechanical action.

[0041] According to a preferred embodiment of the method of the invention, the yeast layer is continuously disrupted during fermentation for at least 0.5 hours, more preferably at least 1 hour, also more preferably at least 2 hours, most preferably between 3 and 120 hours.

[0042] According to another preferred embodiment, the yeast layer is intermittently disrupted. Preferably, according to this embodiment, the method preferably comprises 1 to 1,000 such disruptions of the yeast layer. More preferably, the method comprises 2 to 200 disruptions of the yeast layer. Most preferably, the method comprises 3 to 60 disruptions of the yeast layer.

[0043] The time interval between inoculation and the first disruption of one or more disruptions of the yeast layer, and the time interval between successive disruptions of the yeast layer, is preferably in the range of 0.1 to 50 hours, more preferably 0.5 to 30 hours.

[0044] Disrupting the yeast layer by sparging preferably involves sparging with nitrogen or carbon dioxide. Most preferably, carbon dioxide is used for sparging.

[0045] Breakdown by recirculation may be suitably accomplished by pumping the wort out of the vessel and reintroducing the wort into the vessel so that the yeast layer is broken down.

[0046] Examples of mechanical actions that can be used to disrupt the yeast layer are stirring, shaking, and cutting.

[0047] In embodiments of the invention where a very large amount of yeast is inoculated into the wort, preferably at least 5×10 6 Yeast cells / mL wort, preferably 10 7 ~10 8 Yeast cells / mL are inoculated into the wort.

[0048] The concentration of 2-methylbutanal in the wort is preferably reduced by the fermentation process by at least 70%, more preferably by at least 80%, and most preferably by at least 90%.

[0049] The concentration of 3-methylbutanal in the wort is preferably reduced by the fermentation process by at least 70%, more preferably by at least 80%, and most preferably by at least 90%.

[0050] The concentration of 2-methylpropanal in the wort is preferably reduced by the fermentation process by at least 70%, more preferably by at least 80%, and most preferably by at least 90%.

[0051] Preferably, the concentration of methional in the wort is reduced by the fermentation process by at least 70%, more preferably by at least 80%, and most preferably by at least 90%.

[0052] During the fermentation step of the method of the present invention, substantially no ethanol is produced by the yeast. Therefore, the bulk of the fermentable sugars present in the wort before fermentation is also present in the alcohol-free beer obtained by the method according to the present invention. Thus, in a preferred embodiment, the alcohol-free beer contains 20-90 g / L, more preferably 25-80 g / L and most preferably 30-65 g / L of fermentable sugars selected from glucose, maltose, maltotriose and combinations thereof.

[0053] According to a particularly preferred embodiment, the method of the invention comprises the steps of: 2-Methylbutanal 0-6 μg / L, preferably 0-5 μg / L; 3-Methylbutanal 0-14 μg / L, preferably 0-7 μg / L; 2-methylpropanal 0-12 μg / L, preferably 0-6 μg / L; and Methional 0-6 μg / L, preferably 0-4 μg / L; An alcohol-free beer is produced which contains

[0054] The ethanol content of the alcohol-free beer obtained by the method of the present invention is preferably 0 to 0.5% by volume, more preferably 0 to 0.2% by volume, and most preferably 0 to 0.1% by volume.

[0055] Another aspect of the invention relates to an alcohol-free beer having an ethanol content of less than 0.5% by volume, said alcohol-free beer comprising: · 20-90 g / L of fermentable sugars selected from glucose, maltose, maltotriose and combinations thereof; 2-Methylbutanal 0-6μg / L; 3-Methylbutanal 0-14 μg / L; 2-Methylpropanal 0-12 μg / L; Methional 0-6μg / L; Phenylacetaldehyde 8-100 μg / L; and Furfural 30-500μg / L; Including, a combination of 2-methylbutanal, 3-methylbutanal, 2-methylpropanal, and methional is present at a combined concentration of X μg / L; phenylacetaldehyde is present at a concentration of Y μg / L, and furfural is present at a concentration of Z μg / L; and and / or X:Y≦1:2; and / or X:Z≦1:20.

[0056] The alcohol-free beer of the present invention is preferably obtainable, more preferably the alcohol-free beer is obtainable by the production process as described herein above.

[0057] Preferably, the alcohol-free beer contains 25-80 g / L, more preferably 30-65 g / L, and most preferably 35-60 g / L of fermentable sugars selected from glucose, maltose, maltotriose, and combinations thereof.

[0058] According to a particularly preferred embodiment, the alcohol-free beer contains 15-60 g / L of maltose, more preferably 20-50 g / L and most preferably 25-45 g / L.

[0059] The alcohol-free beer of the present invention contains 2-methylbutanal preferably from 0 to 5 μg / L, more preferably from 0.2 to 3 μg / L.

[0060] Alcohol-free beer contains 3-methylbutanal preferably at 0 to 7 μg / L, more preferably at 0.2 to 5 μg / L.

[0061] Alcohol-free beer contains 2-methylpropanal preferably at 0 to 6 μg / L, more preferably at 0.2 to 4 μg / L.

[0062] Alcohol-free beer preferably contains 0 to 4 μg / L, more preferably 0.2 to 3 μg / L, of methional.

[0063] Furfural is an aldehyde and a Maillard reaction product formed during wort boiling. Unlike Strecker aldehyde, the concentration of furfural is not substantially reduced during the fermentation step of the method of the present invention. Preferably, the alcohol-free beer contains furfural at 40-400 μg / L, more preferably 50-300 μg / L.

[0064] Phenylacetaldehyde is a Strecker aldehyde derived from phenylalanine. Phenylacetaldehyde is not as efficiently removed by yeast during low-temperature contact fermentation as the small amount of Strecker aldehyde mentioned above. Preferably, the alcohol-free beer contains 10-80 μg / L of furfural, more preferably 12-50 μg / L of phenylacetaldehyde.

[0065] According to a particularly preferred embodiment of the alcohol-free beer, methional and furfural are present in a weight ratio of less than 1:30, more preferably in a weight ratio of between 1:50 and 1:300.

[0066] According to a particularly preferred embodiment, said X:Y ratio does not exceed 1:3. Most preferably, the X:Y ratio is in the range of 1:20 to 1:4.

[0067] According to a particularly preferred embodiment, said X:Z ratio does not exceed 1:30. Most preferably, said X:Z ratio is in the range of 1:200 to 1:40.

[0068] The alcohol-free beer of the present invention preferably contains at least 1.0 mg / L, more preferably at least 1.5 mg / L, and most preferably 2.0 to 80 mg / L of iso-α-acids, the iso-α-acids being selected from isohumulone, isoadhumulone, isocohumulone, reduced versions of these iso-α-acids, and combinations thereof. The reduced versions of iso-α-acids are tetrahydroiso-α-acids and hexahydroiso-α-acids.

[0069] The ethanol content of alcohol-free beer is preferably 0 to 0.2% by volume, more preferably 0 to 0.1% by volume, and most preferably 0.001 to 0.05% by volume.

[0070] According to a particularly preferred embodiment, the alcohol-free beer of the present invention is an alcohol-free lager beer.

[0071] Preferably, the alcohol-free beer is a pale beer measuring between 4 and 15 EBC units, more preferably between 5 and 11 EBC units.

[0072] The invention is further illustrated by the following non-limiting examples. EXAMPLES

[0073] Example 1 Alcohol-free lager beer was produced from the same wort (15°P) by different cold contact fermentation processes using bottom-fermenting, lager beer yeast.

[0074] Strecker aldehydes (methional, 2-methylbutanal, 3-methylbutanal, 2-methylpropanal) were analyzed at the end of fermentation by headspace solid-phase microextraction (HS-SPME) using a method adapted from Vesely et al. (Analysis of Aldehydes in Beer Using Solid-Phase Microextraction with On-Fiber Derivatization and Gas Chromatography / Mass Spectrometry, Journal of Agricultural and Food Chemistry (2003); 51(24), 6941-6944.) on a GC-MS (Agilent 7890A and 5975C MSD) and a 30 cm x 0.25 mm x 0.25 μm VF17MS column. Derivatization reactions were performed with O-(2,3,4,5,6-pentafluorobenzyl)-hydroxylamine (PFBOA). Helium was used as the carrier gas at a flow rate of 1 mL / min.

[0075] Beer A (control) was produced by inoculating the wort with 50 g / hL of wet yeast (recovered at the end of regular lager beer fermentation) at the beginning of the cold contact fermentation. The temperature was maintained at 0-2°C and the fermentation time was 48 h, after which the yeast was removed from the beer by membrane filtration.

[0076] After 24 hours, beer 1 was produced in the same way as beer A, except that the yeast was removed by membrane filtration, after which the wort was pitched with 125 g / hL of wet yeast (recovered at the end of the regular lager beer fermentation) and a second fermentation was started again at a temperature of 0-2°C for 24 hours.

[0077] Beer 2 was produced in the same way as beer 1, except that the wort was inoculated with 150 g / hL of washed yeast and the yeast was removed after 24 hours, pitching the wort with 150 g / hL of washed yeast. Washed yeast was prepared by harvesting yeast at the end of a regular lager beer fermentation. This yeast was washed twice by removing the liquid (beer) by centrifugation and subsequent resuspension in deaerated cold water.

[0078] Beer 3 was produced in the same manner as Beer A, except that the wort was inoculated with 300 g / hL of washed yeast prepared in the same manner as above.

[0079] One gram of wet yeast contains approximately 2.8 x 10 9 It corresponds to a yeast cell.

[0080] The concentrations of the four Strecker aldehydes were determined in beers A.1, 2 and 3, respectively, and the results are shown in Table 1.

[0081] [Table 1]

[0082] Example 2 Alcohol-free lager beers were produced from the same wort (15°P) by different cold contact fermentation processes. Again, the combined concentrations of the four Strecker aldehydes were determined for each beer.

[0083] Beer 1 was produced by inoculating the wort with 175 g / hL of wet yeast (recovered at the end of a regular lager beer fermentation). The temperature was 0-2°C and the fermentation time was 48 hours, after which the yeast was removed from the beer by membrane filtration.

[0084] Beer 2 was produced in the same manner as Beer 1, except the fermented wort was intermittently sparged with CO for 15 minutes every 2 hours for 24 hours to disturb the yeast layer. After 24 hours, CO sparging was stopped.

[0085] The concentrations of the four Strecker aldehydes were determined in each of beers 1 and 2. The results are shown in Table 2.

[0086] [Table 2]

Claims

1. 1. A method for producing alcohol-free beer, comprising: Providing a vessel containing at least 10 hL of wort having a specific gravity of 5 to 25°P; At least 10 ５ inoculating the wort with yeast at 1000 cells / mL, so that the yeast forms a sedimentary layer at the bottom of the vessel or a floating layer below the surface of the wort; - fermenting the wort at a temperature of -3 to 5°C for at least 8 hours to produce a fermented wort; - separating the fermented wort from the yeast to produce alcohol-free beer; (a) applying one or more pitches of additional yeast to the inoculated wort during the fermentation, wherein each of the one or more pitches is 10 mL of yeast per mL of wort; ５ ~5 x 10 ６ providing a dose of yeast cells, and at least one of said one or more pitchings is applied at least one hour after said inoculation; or (b) one or more disruptions of the layer of yeast are applied during the fermentation, with at least one of the one or more disruptions being applied at least one hour after the inoculation or continuing until at least one hour after the inoculation; or (c) at least 3 x 10 per mL of wort at the beginning of the fermentation ６ inoculating the wort with yeast cells; and The process does not include the addition of a Strecker aldehyde selected from 2-methylbutanal, 3-methylbutanal, and methional.

2. The method of claim 1, wherein the wort contains at least 20 μg / L of 2-methylbutanal.

3. The method of claim 1, wherein the wort contains at least 40 μg / L of 3-methylbutanal.

4. 2. The method of claim 1, wherein the wort contains at least 16 μg / L of methional.

5. 5. The method of claim 1, wherein the yeast is selected from Saccharomyces pastorianus, Saccharomyces uvarum, Saccharomyces cerevisiae, and combinations thereof.

6. 6. The method of claim 5, wherein the yeast is Saccharomyces pastorianus.

7. 5. The method according to any one of claims 1 to 4, wherein the yeast is a bottom-fermenting yeast and the yeast is allowed to form a layer at the bottom of the fermenter after inoculation.

8. 5. The method according to any one of claims 1 to 4, wherein the layer of yeast has a thickness of at least 0.1 mm.

9. 10 per 1 mL of wort ５ ~5 x 10 ６ 5. The method of any one of claims 1 to 4, comprising 1 to 100 pitches of additional yeast in a dose of yeast cells, and wherein the time interval between the inoculation and the first of the 1 to 100 pitches and between successive additional pitches is in the range of 0.5 to 50 hours.

10. 5. The method according to any one of claims 1 to 4, comprising 1 to 1,000 disruptions of the layer of yeast, and wherein the time interval between the inoculation and the first of the 1 to 1,000 disruptions and between successive disruptions is in the range of 0.1 to 50 hours.

11. 5. The method according to any one of claims 1 to 4, wherein the yeast layer is continuously disrupted during the fermentation for at least 0.5 hours.

12. 1. An alcohol-free beer having an ethanol content of less than 0.5% by volume, comprising: 20 to 90 g / L of fermentable sugars selected from glucose, maltose, maltotriose, and combinations thereof; 2-methylbutanal 0-6 μg / L; 3-methylbutanal 0-14 μg / L; 2-methylpropanal 0-12 μg / L; Methional 0-6 μg / L; phenylacetaldehyde 8 to 100 μg / L; and furfural 30-500 μg / L; Including, A combination of 2-methylbutanal, 3-methylbutanal, 2-methylpropanal, and methional is present at a combined concentration of X μg / L; phenylacetaldehyde is present at a concentration of Y μg / L, and furfural is present at a concentration of Z μg / L; and X:Y≦1:2; and / or An alcohol-free beer in which X:Z≦1:

20.

13. The alcohol-free beer according to claim 12, which contains 15 to 60 g / L of maltose.

14. The alcohol-free beer according to claim 12, containing 0.2 to 3 μg / L of methional.

15. 13. The alcohol-free beer of claim 12, wherein methional and furfural are present in a weight ratio of less than 1:30.