Energy efficient process for the production of fermented malt beverages

Abstract

The invention relates to a process of producing a fermented malt beverage that comprises the following steps: a) preparing an aqueous malt mixture comprising water and malt; b) preparing a mash by mashing the aqueous malt mixture; c) separating the mash into wort and spent grain; d) holding the wort at a temperature of at least 70⁰C for a time period of at least 5 minutes to produce a heated wort; e) cooling the heated wort to a temperature of less than 30⁰C to produce a cooled wort; and f) contacting the cooled wort with active yeast for at least 8 hours to produce a fermented wort; wherein the temperature of the wort is maintained below 90 ⁰C between steps c) and f); wherein boiling of the wort is avoided; wherein hot trub is removed from the heated wort prior to step f); and wherein an anionic flocculant is added to the wort prior to the removal of the hot trub. The invention also provides a beer characterised by a total dimethyl sulphide content of at least 50 µg / L, a difference between the total dimethyl sulphide content and the free dimethyl sulphide content in the range of 40-250 µg / L and a thiobarbituric acid number of 16-33.

Description

[0001] ENERGY EFFICIENT PROCESS FOR THE PRODUCTION OF FERMENTED MALT BEVERAGES

[0002] Technical field of the invention

[0003] The invention provides an energy efficient process for the production of fermented malt beverages, the process comprising: a) preparing an aqueous malt mixture comprising water and malt; b) preparing a mash by mashing the aqueous malt mixture; c) separating the mash into wort and spent grain; d) holding the wort at a temperature of at least 70°C for a time period of at least 5 minutes to produce a heated wort; e) cooling the heated wort to a temperature of less than 30°C to produce a cooled wort; and f) contacting the cooled wort with active yeast for at least 8 hours to produce a fermented wort; wherein the temperature of the wort is maintained below 90 °C between steps c) and f); wherein boiling of the wort is avoided, wherein hot trub is removed from the heated wort prior to step f) and wherein an anionic flocculant is added to the wort prior to the removal of the hot trub .

[0004] The process according to the present invention yields fermented malt beverages of high quality whilst at the same time achieving significant energy savings compared to existing processes for the production of fermented malt beverages.

[0005] This invention also relates to a beer characterised by a total dimethyl sulphide content of at least 50 pg / L, a difference between the total dimethyl sulphide content and the free dimethyl sulphide content in the range of 40-250 pg / L and a thiobarbituric acid number of 16-33.

[0006] Background of the invention

[0007] Fermented malt beverages such as beer and whiskey are produced by a process that typically comprises the following steps:

[0008] • preparing an aqueous malt mixture comprising water and malt;

[0009] • preparing a mash by mashing the aqueous malt mixture;

[0010] • separating the mash into wort and spent grain;

[0011] • boiling the wort; • cooling the boiled wort to a temperature of less than 30°C to produce a cooled wort; and

[0012] • fermenting the cooled wort with active yeast.

[0013] In the conventional production of beer, wort boiling is a critical process step that serves multiple purposes, including:

[0014] • inactivation of enzymes,

[0015] • sterilization,

[0016] • coagulation and precipitation of proteins,

[0017] • concentration of sugars through evaporation,

[0018] • isomerization of a-acids from hops,

[0019] • conversion of S-methylmethionine into dimethyl sulphide,

[0020] • removal of unwanted volatile flavour components.

[0021] During wort boiling two main processes can be distinguished: hot holding and evaporation. During hot holding, different chemical reactions take place, such as: hop isomerization, development of aroma and colour substances, inactivation of enzymes, protein coagulation and sterilization. On the other hand, evaporation serves to remove undesired aroma substances, especially dimethyl sulphide (DMS).

[0022] DMS is a malt-derived flavour substance with a very low flavour threshold of 40-60 ppb, which is produced by thermal decomposition of S-methylmethionine (SMM). DMS formed by wort boiling is rapidly lost by evaporation but SMM will continue to break down during wort cooling and the DMS formed then will persist into beer. To minimize such DMS formation it is recommended to use malts with low SMM content and to extend the wort boiling time to decompose the majority of the precursor and drive off the DMS. DMS is highly undesirable as it presents an unpleasant taste and smell in the final beer.

[0023] After the wort boiling phase, usually the so-called hot trub separation takes place in, for example, a whirlpool. Typically, the wort is cooled to temperatures below 90 °C before the hot trub separation. This cooling can either be achieved with a heat exchanger or a flash evaporator.

[0024] As society becomes more conscious about the impact of human activities on the environment, there has been a growing emphasis on the development of more sustainable, more energy efficient production processes. Since wort boiling is one of the most energy-consuming process steps in the brewery, it is highly desirable to replace wort boiling by a more energy efficient alternative.

[0025] Desobgo (The wort boiling techniques and energy requirements: A Review, The 1stInternational Conference on Local Resource Exploitation, Ngaoundere, Cameroon (2021), 939-956) provides a review of different wort boiling technologies and estimates the specific energy requirements of each of the technologies. The article discusses a wort boiling technique that was introduced by Maule and Clark in 1985 in which wort was heated up to 93 °C. It also discusses a vacuum boiling system (300 mbar, 69 °C) that was introduced by the company Kaspar Schulz (Bamberg, Germany).

[0026] EP-A 3 760 700 describes a process for treating a wort composition in a kettle, the process comprising the steps of:

[0027] (a) providing a kettle provided with a gas sparging system;

[0028] (b) adding wort from a mash separating step into said kettle;

[0029] (c) heating said wort to a target temperature between 80 and 96°C;

[0030] (d) maintain an average target temperature between 80 and 96°C for a period of 12-45 minutes, and during which period gas sparging of less than 10 g / hL / hr, preferably no gas sparging, takes place;

[0031] (e) raising the temperature of the wort composition to a target temperature of between 97°C and 99°C;

[0032] (f) sparging a gas through the wort composition at an average rate of 80-350 g / hl / hr while maintaining an average target temperature of between 97°C and 99°C for a period of between 15 minutes and 75 minutes; and during which the wort composition does not reach its boiling point; and

[0033] (g) transferring the treated wort composition to a trub separation step.

[0034] WO 2015 / 067737 concerns a process for treating a wort in a kettle, said method comprising the steps of:

[0035] (a) providing: a kettle provided with a gas sparging system suitable for sparging an inert gas into said wort,

[0036] (b) feeding wort from a lautering step into said boiling kettle, said wort being at a temperature below its boiling temperature;

[0037] (c) while sparging an inert gas through the wort, heating said wort to, and maintaining it at a treatment temperature, Ta, which is below the boiling temperature, Tt>, of the wort for a duration, tt, comprised between 15 and 90 min, and no longer than required to evaporate at most 4 wt.% of water initially present in the wort; (d) transferring the treated wort to a trub separation step.

[0038] GB-A 2280908 describes a process for the clarification of a beverage brew comprising adding to the brew wort a mixture of a linear sulphated polysaccharide and silica sol.

[0039] WO 2021 / 155258 describes a method of controlling off-flavours of low-alcohol beer, comprising:

[0040] • mashing a selected malted barley variety in a mash conversion vessel forming a mash;

[0041] • separating the mash forming a wort;

[0042] • transferring the wort to a kettle; and

[0043] • adding, during boiling of the wort, an amount of tannic acid to the wort in the kettle, wherein the amount of tannic acid precipitates precursors or inhibits reactions that lead to the formation of Strecker aldehydes in the low-alcohol beer.

[0044] Dugulin et al. (Brewing with 100% green malt - process development and key quality indicators, J. Inst. Brew. (2020); 126: 343-353) describes beers that were brewed with undried, germinated (green) malt. Six green malt beers were brewed with acceptable specifications in terms of pH, alcohol content, foam stability and colour. No significant taints or obvious defects were detected in green malt beers. Increased S-methyl methionine levels were measured in worts and beers made from green malt, however DMS concentrations in the finished beers did not differ significantly from the reference beers.

[0045] Schwill-Miedaner (Wort boiling today - are there alternatives?, Brauwelt International (2003), 21(1) 42-48) reports that wort boiling on average accounts for 33-50% of total heat requirements in a brewery and that large energy quantities (about 55 % primary energy) can be saved by adopting measures such as reducing total evaporation and using heat recovery.

[0046] Hertel et al. (Low temperature wort flavour evaporation: A new dimension in evaporation Efficiencies, Cerevisia 36 (2011) 11-16) report that the vapour liquid equilibrium of wort flavour components in wort and thus the efficiency of evaporation processes during the production of beer can be influenced by means of changing the evaporation temperature. According to the authors, using an evaporation of unwanted flavours in the cold parts of the brewery leads to enormous advantages.

[0047] Willaert et al. (Wort Boiling Today - Boiling Systems with Low Thermal Stress in Combination with Volatile Stripping, Cerevisia: Belgian Journal of Brewing and Biotechnology, 26(4) (2001) 217-230) discuss wort boiling objectives, possibilities to reduce the thermal stress on wort and environmental aspects of wort boiling.

[0048] Summary of the invention

[0049] The inventors have unexpectedly discovered that good quality fermented malt beverages can be produced by an energy efficient process in which the conventional wort boiling step is replaced by a mild heat treatment of the wort and wherein anionic flocculant is added to the wort before or during the mild heat treatment.

[0050] Accordingly, a first aspect of the invention relates to a process of producing a fermented malt beverage that comprises the following steps: a) preparing an aqueous malt mixture comprising water and malt; b) preparing a mash by mashing the aqueous malt mixture; c) separating the mash into wort and spent grain; d) holding the wort at a temperature of at least 70°C for a time period of at least 5 minutes to produce a heated wort; e) cooling the heated wort to a temperature of less than 30°C to produce a cooled wort; and f) contacting the cooled wort with active yeast for at least 8 hours to produce a fermented wort; wherein the temperature of the wort is maintained below 90 °C between steps c) and f), wherein boiling of the wort is avoided, wherein hot trub is removed from the heated wort prior to step f) and wherein an anionic flocculant is added to the wort prior to the removal of the hot trub.

[0051] Although the inventors do not wish to be bound by theory, it is believed that, although in the present process evaporative removal of dimethyl sulphide during the mild heat treatment of the wort is limited, due to the mild heating conditions, formation of dimethyl sulphide is also effectively minimized. Thus, even though the present process does not employ a conventional wort boiling step, the beer obtained by the process does not suffer from flavour defects associated with the presence of dimethyl sulphide. Furthermore, the addition of anionic flocculant to the wort effectively reduces the formation of off-flavour notes during wort heating and / or aids the removal of off-flavour generating components together with the hot trub.

[0052] The heat load to which the fermented malt beverage is exposed in the present process is lower than in conventional processes, resulting in a malt beverage having a relatively low thiobarbituric acid number and a relatively high S-methylmethionine content. Furthermore, by avoiding wort boiling, formation of dimethyl sulphide from S-methylmethionine is suppressed. In other words, in the present process only a fraction of the S-methylmethionine in the wort is converted into dimethyl sulphide. Consequently, the beers obtained by the present invention are characterized by a low thiobarbituric acid number, an extraordinary high S- methylmethionine content, and a low content of dimethyl sulphide.

[0053] Accordingly, the invention also provides a beer characterised by a total dimethyl sulphide content of at least 50 pg / L, a difference between the total dimethyl sulphide content and the free dimethyl sulphide content in the range of 40-250 pg / L and a thiobarbituric acid number of 16-33.

[0054] Detailed description of the invention

[0055] The present invention provides a process of producing a fermented malt beverage that comprises the following steps: a) preparing an aqueous malt mixture comprising water and malt; b) preparing a mash by mashing the aqueous malt mixture; c) separating the mash into wort and spent grain; d) holding the wort at a temperature of at least 70°C for a time period of at least 5 minutes to produce a heated wort; e) cooling the heated wort to a temperature of less than 30°C to produce a cooled wort; and f) contacting the cooled wort with active yeast at a temperature of less than 7°C for at least

[0056] 8 hours to produce a fermented wort; wherein the temperature of the wort is maintained below 90 °C between steps c) and f), wherein boiling of the wort is avoided, wherein hot trub is removed from the heated wort prior to step f) and wherein an anionic flocculant is added to the wort prior to the removal of the hot trub.

[0057] The term “alcohol” as used herein refers to ethanol, unless indicated otherwise.

[0058] The term “malt” as used herein refers to malted cereal grain, such as malted barley.

[0059] The term “100% malt beer” as used herein refers to a beer that has been produced from malt only, i.e. without using any non-malted adjuncts (e.g., non-malted starch sources and / or sugar syrups).

[0060] The term “or” as used herein should be construed as “and / or”, unless specified otherwise. The term “a” or “an” as used herein is defined as “at least one” unless specified otherwise.

[0061] The term “iso-alpha acids” as used herein refers to substances selected from the group of isohumulone, isoadhumulone, isocohumulone, pre-isohumulone, post-isohumulone and combinations thereof. The term “iso-alpha acids” encompasses different stereo-isomers (cis- iso-alpha acids and trans-iso-alpha acids). Iso-alpha acids are typically produced in beer from the addition of hops to the boiling wort. They may also be introduced into the beer in the form of pre-isomerised hop extract. Iso-alpha-acids are intensely bitter with an estimated threshold value in water of approximately 6 ppm.

[0062] The term “hydrogenated iso-alpha acids” refers to substances selected from dihydro-iso-alpha acids, tetrahydro-isoalpha acids, hexahydro-iso-alpha acid and combinations thereof.

[0063] The term “hulupones” as used herein refers to substances selected from cohulupone, n- hulupone, adhulupone and combinations thereof. Hulupones are oxidation products of hop beta-acids.

[0064] The term “gas” as used herein refers to an element, a substance, a mixture of elements, a mixture of substances or a mixture of elements and substances that is in a gaseous state under the conditions employed in the present process. Nitrogen, carbon dioxide, air and steam are examples of gases that may be employed in the present process.

[0065] The free dimethyl sulphide content of a beer equals the concentration of dimethyl sulphide (DMS) that is present in the beer as determined by means of HS-GC / MS using the method that is described by Stafisso et al. (DETERMINATION OF DIMETHYL SULPHIDE IN BREWERY SAMPLES BY HEADSPACE GAS CHROMATOGRAPHY MASS SPECTROMETRY (HS-GC / MS, Italian Journal of Food Science, January 2011 , 19-27).

[0066] The total dimethyl sulphide content of a beer equates the concentration of dimethyl sulphide that is present in beer after it has undergone a treatment to quantitatively convert S- methylmethionine (SMM) into DMS, as described in the aforementioned paper by Stafisso et al. Thus, SMM content of a beer in DMS equivalent can be calculated by subtracting the free DMS content from the total DMS content.

[0067] The fermented malt beverage that is produced by the present process preferably is a beer, even more preferably a lager beer. The malt that is applied in the aqueous malt mixture of step a) preferably is selected from malted barley, malted sorghum, malted wheat, malted rye and combinations thereof. Most preferably, the malt employed is malted barley.

[0068] The aqueous malt mixture that is prepared in step a) of the present process, besides water and malt, may contain adjuncts. Preferably, malt represents at least 10 wt.%, more preferably at least 30 wt.%, even more preferably at least 50 wt.% more preferably at least 60 wt.% of the dry matter that is present in the aqueous malt mixture.

[0069] According to another preferred embodiment, malt and unmalted cereal grain together represent at least 70 wt.% more preferably at least 85 wt.% of the dry matter that is present in the aqueous malt mixture. Even more preferably, all dry matter in the aqueous malt mixture is provided by malt and unmalted cereal grain. Most preferably all dry matter in the aqueous malt mixture is provided by malt.

[0070] In the mashing step of the present process, enzymes present in the malt (notably amylases) are allowed to break down starch into fermentable sugars, such as maltose. The mashing step may suitably be carried out as an infusion mashing or a decoction mashing.

[0071] During the preparation of the mash in the present process, the temperature of the aqueous malt mixture preferably is maintained below 95 °C, more preferably is maintained below 90°C, even more preferably below 85 °C during the mashing step b).

[0072] The mashing step b) of the present process preferably comprises heating of the aqueous malt mixture to a temperature of at least 60 °C, more preferably to at least 65 °C and most preferably of at least 70 °C.

[0073] The separation of the mash in wort and spent grain may suitably be carried out in a solid-liquid separation device. Examples of such solid-liquid separation devices include lauter tuns, mash / lauter vessels and mash filters.

[0074] Examples of anionic flocculants that may be used in the present process include tannin, carrageenan, alginate and combinations thereof. In accordance with one embodiment of the invention, the anionic flocculant is tannin, more preferably tannic acid. Brewtan® B is an example of a commercially available tannic acid that may be used an anionic flocculant in the present process.

[0075] In accordance with another embodiment of the invention the anionic flocculant is selected from carrageenan, alginate and combinations thereof. More preferably, the anionic flocculant is carrageenan, most preferably kappa-carrageenan. Whirlfloc® is an example of a kappa- carrageenan that may be used an anionic flocculant in the present process.

[0076] According to a particularly preferred embodiment, the present process employs a combination of at least two anionic flocculants, including tannin and carrageenan, more preferably including tannic acid and kappa-carrageenan.

[0077] The total amount of the anionic flocculant that is added to the wort is preferably in the range of 0.5-20 grams per hL of wort, more preferably in the range of 1-15 grams per hL of wort, most preferably in the range of 2-11 grams per hL of wort.

[0078] In the present process, the flocculant is preferably added before or during the heating of the wort in step d). Preferably, the flocculant is added at least 3 minutes, more preferably at least 5 minutes and most preferably at least 8 minutes before the end of the heating step d).

[0079] Between steps c) and f) of the present process the temperature of the wort is preferably maintained below 86 °C, more preferably is maintained below 84 °C and most preferably is maintained below 82 °C.

[0080] Preferably, the wort is held at a temperature in the range of at least 70 °C for 10-100 minutes, more preferably for 30-90 minutes, even more preferably for 35-85 minutes, and most preferably for 40-80 minutes.

[0081] According to a particularly preferred embodiment, the wort is held at a temperature in the range of 73-85°C for at least 5 minutes, preferably for 10-100 minutes, more preferably for 30- 90 minutes, even more preferably for 35-85 minutes, and most preferably for 40-80 minutes.

[0082] The holding of the wort in step d) is preferably carried out at a pressure of at least 0.8 atm., more preferably at a pressure of 0.85-1.5 atm., most preferably at a pressure of 0.9-1 .2 atm. The inventors have unexpectedly discovered that the flavour of the final beverage is improved if the wort is sparged with gas during heating step d). It is believed that sparging of the wort during said heat treatment aids coagulation and precipitation of proteins and removal of hot trub. As already mentioned above, effective removal of hot trub is associated with a reduction of off-flavour in the final beverage.

[0083] Preferably, the gas that is sparged through the wort in the present process is selected from air, nitrogen, carbon dioxide and steam. More preferably the gas is selected from air and nitrogen. Most preferably the gas is air. Although the inventors do not wish to be bound by theory, it is believed that the oxygen that is present in air oxidizes precursors of volatile off- flavour compounds. These volatile off-flavours are subsequently carried off by the sparging gas. Thus, the wort that is obtained after sparging with air has a substantially reduced content of oxidizable flavour precursors compared to a wort that has not been sparged with air, and is less prone to developing off-flavours after the heating of the wort.

[0084] In the present process, gas may be sparged through the wort by introducing the gas near the bottom of a vessel that contains the wort and allowing gas bubbles to travel upwards through the wort.

[0085] In a preferred embodiment, the gas is sparged through the wort when the wort is held at a temperature in the range of 72-86 °C, more preferably at a temperature in the range of 74-84 °C and most preferably a temperature in the range of 75-82 °C.

[0086] The total amount of gas that is sparged through the wort when it is held at a temperature that is within one of the aforementioned temperature ranges preferably is at least 20 gram per hl of wort, more preferably 50 to 1 ,200 grams per hl of wort, even more preferably 100 to 1 ,000 grams per hl of wort and most preferably 150 to 800 grams per hl of wort.

[0087] In the present process, the gas may be sparged through the wort continuously or intermittently.

[0088] Preferably, the total period during which gas is sparged through the wort is at least 1 minute, more preferably 5 to 80 minutes, even more preferably 10 to 60 minutes and most preferably 15 to 45 minutes.

[0089] Preferably, the gas is sparged through the wort at a rate that is within the range of 20 to 1 ,500 g / hl / hr, more preferably within the range of 30 to 1 ,200 g / hl / hr, even more preferably within the range of 40 to 900 g / hl / hr and most preferably within the range of 50 to 700 g / hl / hr. The hot trub may be removed from the heated wort by solid-liquid separation techniques known in the art. Preferably, the hot trub is removed in a whirlpool.

[0090] Removal of the hot trub is preferably carried out when the heated wort has a temperature of at least 50 °C, more preferably of at least 70 °C.

[0091] According to a particularly preferred embodiment of the present process a source of hop acids is added to the wort, preferably before the contacting of the cooled wort with active yeast. The source of hop acids is preferably added to the wort in an amount providing 1 to 80 mg / L of hop acids selected from iso-alpha acids, hydrogenated iso-alpha acids, hulupones and combinations thereof. More preferably, source of hop acids is added to the wort in an amount providing 2 to 40 mg / L of the hop acids, most preferably 3 to 30 mg / L of the hop acids.

[0092] Preferably, the source of hop acids is a source of iso-alpha acids selected from isomerised hop extract, isomerised hop pellets and combinations thereof.

[0093] Preferably, the source of hop acids is added to the wort during step d) or during removal of the hot trub, especially during removal of the hot trub in a whirlpool.

[0094] In the process according to the present invention, the wort is contacted with active yeast. The yeast is preferably selected from Saccharomyces, more preferably from Saccharomyces pastorianus, Saccharomyces uvarum, Saccharomyces cerevisiae and combinations or hybrids thereof, most preferably the yeast is Saccharomyces pastorianus.

[0095] The contacting of the cooled wort with active yeast preferably comprises inoculation of the wort with at least 105cells / mL of yeast, preferably of 3x105-3x107cells / mL of yeast. Typically, the yeast is allowed to form a settled layer on the bottom of the vessel that holds the inoculated cooled wort or it is allowed to form a floating layer below the surface of the wort. Most preferably, the yeast is allowed to form a settled layer on the bottom of the vessel.

[0096] The present process may suitably be used to produce alcoholic as well as non-alcoholic fermented malt beverages.

[0097] In one preferred embodiment of the present process the cooled wort is contacted with active yeast at a temperature of 5 to 40 °C for at least 8 hours to produce an alcoholic fermented wort having an alcohol content of 3-12% ABV, more preferably of 4-7% ABV. More preferably, the cooled wort is contacted with active yeast at a temperature of 6 to 30 °C, most preferably of 8 to 15°C.

[0098] In the embodiment in which the present process is used to produce an alcoholic fermented wort, the cooled wort is preferably contacted with active yeast at the referred temperatures for at least 20 hours, more preferably 50 to 600 hours, even more preferably 100 to 400 hours.

[0099] In another preferred embodiment, the cooled wort is contacted with active yeast at a temperature of less than 7 °C for at least 8 hours to produce a non-alcoholic fermented wort having an alcohol content of less than 0.5% ABV, more preferably of less than 0.1 % ABV. More preferably, the cooled wort is contacted with active yeast at a temperature of -2 to 5 °C, most preferably of -1 to 4°C.

[0100] In the embodiment in which the present process is used to produce a non-alcoholic fermented wort, the cooled wort is preferably contacted with active yeast at the referred temperatures for at least 4 hours, more preferably 8 to 72 hours, even more preferably 12 to 48 hours. This embodiment of the present process is particularly suited for the production of non-alcoholic fermented malt beverages using so-called cold contact fermentation. The undesirable ‘worty’ flavour that is typical of non-alcoholic beverages that have been produced by cold contact fermentation is virtually absent in the non-alcoholic fermented malt beverages obtained by the present process.

[0101] Following the contacting with active yeast, the fermented wort may be subjected to one or more additional process steps such as conditioning, filtering, carbonation and packaging (e.g. bottling or casking).

[0102] The present invention also pertains to fermented malt beverages that are obtainable, preferably fermented malt beverages that are obtained by the present process.

[0103] A further aspect of the invention relates to a beer characterised by a total dimethyl sulphide content of at least 50 pg / L, a difference between the total dimethyl sulphide content and the free dimethyl sulphide content in the range of 40-250 pg / L and a thiobarbituric acid number of 16-33.

[0104] Preferably, the beer of the present invention is obtainable, more preferably obtained by the process of preparing a fermented malt beverage that is described above. In one embodiment, the beer is an alcoholic beer having an alcohol content of 3-12% ABV, preferably of 4-7% ABV.

[0105] In another embodiment, the beer is a non-alcoholic beer having an alcohol content of less than 0.5% ABV, preferably of less than 0.1 % ABV.

[0106] The non-alcoholic beer is preferably obtained by cold contact fermentation. Non-alcoholic beers obtained by cold contact fermentation as opposed to non-alcoholic beers obtained by de-alcoholisation, contain a substantial amount of maltose. Accordingly, the beer preferably contains at least 3 g / L, more preferably 5-40 g / L and most preferably 8-25 g / L of maltose.

[0107] According to a particularly preferred embodiment, the beer of the present invention is a 100% malt beer.

[0108] Preferably, the beer contains cereal protein selected from barley protein, sorghum protein, wheat protein, rye protein and combinations thereof. Most preferably, the cereal protein is barley protein.

[0109] The beer described herein differs from ordinary beers in that it has been exposed to substantially less heat. The Thiobarbituric Acid Number (TAN) of a beer is indicative for the heat load to which the beer has been exposed. According to a preferred embodiment, the beer according to the invention has a TAN of less than 30, more preferably of less than 26, even more preferably of 18 to 24, most preferably of 19 to 22. The TAN of a beer can be determined by the spectrophotometric method that is described in Manual, Analysis Methods for the Brewery Industry, Spectroquant® Prove, Release 07 / 2017, 101-103.

[0110] The total dimethyl sulphide content of the beer of the present invention preferably is in the range of 80-300 pg / L, more preferably in the range of 100-270 pg / L, even more preferably in the range of 120-250 pg / L and most preferably in the range of 140-230 pg / L.

[0111] The free dimethyl sulphide content of the beer preferably is in the range of 10-200 pg / L, more preferably in the range of 20-160 pg / L and most preferably in the range of 30-140 pg / L.

[0112] The beer of the present invention is characterised in that free dimethyl sulphide represents a relatively low fraction of the total dimethyl sulphide content of the beer. Preferably, free dimethyl sulphide represents at most 70%, more preferably 10-65%, even more preferably 15- 60% and most preferably 20-55% of the total dimethyl sulphide content.

[0113] The difference between the total dimethyl sulphide content and the free dimethyl sulphide content is indicative of the S-methylmethionine content of the beer. For the beer according to the present invention, the difference between the total dimethyl sulphide content and the free dimethyl sulphide content preferably is in the range of 40-250 pg / L, more preferably in the range of 60-190 pg / L and most preferably in the range of 70-140 pg / L.

[0114] According to a particularly preferred embodiment, the beer of the present invention contains bitterness providing hop acids. The beer preferably contains 1 to 80 mg / L, more preferably 2 to 40 mg / L and most preferably 3 to 30 mg / L of hop acids selected from iso-alpha acids, hydrogenated iso-alpha acids, hulupones and combinations thereof.

[0115] The beer of the present invention preferably contains 1-80 mg / L, more preferably 2-40 mg / L and most preferably 3-30 mg / L of iso-alpha acids.

[0116] The beer preferably has a free amino nitrogen (FAN) content of 40 to 150 mg / L, more preferably of 50 to 130 mg / L and most preferably of 60 to 100 mg / L. The FAN content of a beer can suitably be determined using EBC method 9.10.1.

[0117] The beer preferably contains per mg of FAN at least 0.2 pg of total dimethyl sulphide, more preferably 0.4-5 pg of total dimethyl sulphide, even more 0.5-4 pg of total dimethyl sulphide, and most preferably 0.6-3 pg of total dimethyl sulphide.

[0118] The TAN of a beer is affected by the degree of dilution that occurs after production of the heated wort. Alcohol-free beer that is produced by cold contact fermentation, for instance, may be diluted substantially after the fermentation step to reduce sweetness. The TAN of a beer is also affected by the use of adjuncts. Both dilution and the use of adjuncts result in a lowering of TAN, as well as in a lowering of FAN. According to a preferred embodiment, the TAN and FAN of the beer of the present invention meets the following condition: TAN < 0.35xFAN, wherein FAN is expressed in mg / L. More preferably, the beer meets the following condition TAN < 0.28xFAN and most preferably the beer meets the following condition TAN < 0.25xFAN.

[0119] The invention is further illustrated by the following non-limiting examples.

[0120] Examples Example 1

[0121] A mash was prepared as follows: ground barley malt and water were combined in a weight ratio of 1 :3 at 60 °C pH was adjusted to 5.6 with HCI solution calcium chloride was added to increase calcium content to 159 ppm. mashing in at 60 °C in 10 minutes protein rest at 60 °C for 5 minutes heating to 66 °C in 12 minutes saccharification rest at 66 °C for 25 minutes heating to 76 °C in 10 minutes mashing off rest at 76 °C for 5 minutes

[0122] The mash was filtered with a mash filter, producing an amount of spent grains and a separate wort stream. The wort pH was adjusted to 5.2 (HCI or KOH).

[0123] The wort so obtained was subjected split into 5 different volumes that were subjected to different heating regimes with and without addition of anionic flocculant as shown in Table 1 . In all cases 7.85 g / hl of IKE (58.8% iso-alpha acids) was added 15 minutes before the end of the heating step.

[0124] Table 1

[0125] S.A. Ajinomoto OmniChem N.V, Belgium - added at the beginning of the heating step

[0126] KERRY, Ireland - added 15 minutes before the end of the heating step

[0127] All five worts were transferred to a whirlpool vessel, with a rest of 10 minutes, after which they were cooled to 8 °C. The worts were aerated with 44 ppm oxygen and put in a fermentation tank, where 350 g / hl of yeast (at 100% consistency) was pitched. The zinc concentration was adjusted to 0.5 mg / l. Fermentation was carried out at 10 °C, and when an extract of 7 “Plato was reached, the temperature was allowed to elevate to maximum 14 °C. Once diacetyl levels were below 15 ppb, the fermented wort was deep cooled and kept at -1 °C for several days. Next, 30 g / hl of PVPP was added before filtration over a beer membrane filter. Final products were standardized to 5% ABV, 5.2 g / l of CO2, a bitterness of 20 Bll and a colour of 7 EBC.

[0128] The beers so obtained were blindly evaluated by an expert panel. The beer made from wort A was rated as ‘unacceptable’. All the other beers were rated from ‘acceptable’ to ‘good’. The beer made from boiled wort was preferred over the other beers. The beer made from wort D was preferred over worts A, B and C.

[0129] Example 2

[0130] Two alcohol-free beers are prepared from wort B as described in Example 1. One of the two worts is sparged with air during the heating period at a flow rate of 7.7 liter / hl / minute (596 g / hl / hr).

[0131] The beers so obtained are blindly evaluated by an expert panel. The taste of the beer made from the wort that has been sparged with air is preferred.

Claims

CLAIMS1. A process of producing a fermented malt beverage, said process comprising the following steps: a) preparing an aqueous malt mixture comprising water and malt; b) preparing a mash by mashing the aqueous malt mixture; c) separating the mash into wort and spent grain; d) holding the wort at a temperature of at least 70°C for a time period of at least 5 minutes to produce a heated wort; e) cooling the heated wort to a temperature of less than 30°C to produce a cooled wort; and f) contacting the cooled wort with active yeast for at least 8 hours to produce a fermented wort; wherein the temperature of the wort is maintained below 90 °C between steps c) and f); wherein boiling of the wort is avoided; wherein hot trub is removed from the heated wort prior to step f); and wherein an anionic flocculant is added to the wort prior to the removal of the hot trub.

2. Process according to claim 1, wherein the anionic flocculant is tannin, preferably tannic acid.

3. Process according to claim 1 , wherein the anionic flocculant is selected from carrageenan, alginate and combinations thereof.

4. Process according to claim 3, wherein the anionic flocculant is kappa-carrageenan.

5. Process according to any one of the preceding claims, wherein 0.5-20 grams of flocculant are added per hL of wort.

6. Process according to any one of the preceding claims, wherein flocculant is added at least 3 minutes before the end of the heating step d).

7. Process according to any one of the preceding claims, wherein gas is sparged through the wort during at least a part of the time period during which the wort is held at a temperature of at least 70°C.

8. Process according to claim 7, wherein the gas is selected from air, nitrogen, carbon dioxide and mixtures thereof.

9. Process according to any one of the preceding claims, wherein the holding of the wort is carried out at a pressure of at least 0.8 atm.

10. Process according to any one of the preceding claims, wherein the wort is held at a temperature of at least 70°C for 10-100 minutes.

11. Process according to any one of the preceding claims, wherein the fermented malt beverage is beer, preferably lager beer.

12. Process according to any one of the preceding claims, wherein the contacting of the cooled wort with active yeast yields a fermented wort having an ethanol content of at least 3% ABV.

13. A beer characterised by a total dimethyl sulphide content of at least 50 pg / L, a difference between the total dimethyl sulphide content and the free dimethyl sulphide content in the range of 40-250 pg / L and a thiobarbituric acid number of less than 33.

14. Beer according to claim 13, wherein free dimethyl sulphide represents at most 35% of the total dimethyl sulphide content.

15. Beer according to claim 13 or 14, wherein the beer has a free amino nitrogen (FAN) content of 40 to 150 mg / L.

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