Energy-saving process for producing a fermented malt beverage

Abstract

The invention relates to a method of producing a fermented malt beverage, the method comprising the steps of: a) preparing an aqueous malt mixture comprising water and malt; b) preparing a malt mash by mashing the aqueous malt mixture; c) separating the malt mash into wort and spent grain; d) holding the wort at a temperature of at least 70 °C for a 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 the wort is not boiled; wherein heat coagulum is removed from the heated wort prior to step f); and wherein an anionic flocculating agent is added to the wort prior to removal of the heat coagulum. The invention also provides a beer characterized by a total dimethyl sulfide content of at least 50 µg / L, a difference between the total dimethyl sulfide content and the free dimethyl sulfide content in the range of 40-250 µg / L, and a thiobarbituric acid value of 16-33.

Description

Technical Field

[0001] This invention provides an energy-saving method for producing fermented malt beverages, the method comprising: a) Prepare an aqueous malt mixture containing water and malt; b) Prepare malt paste by saccharifying the aqueous malt mixture; c) Separate the malt pulp into wort and lees; d) Keep the wort at a temperature of at least 70°C for at least 5 minutes to produce heated wort; e) Cool the heated wort to a temperature below 30°C to produce cooled wort; and f) Contact the cooled wort with active yeast for at least 8 hours to produce fermented wort; Between steps c) and f), the temperature of the wort is maintained below 90°C; wherein boiling of the wort is avoided; wherein hot coagulants are 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 coagulants.

[0002] Compared with existing methods for producing fermented malt beverages, the method according to the present invention produces high-quality fermented malt beverages while achieving significant energy savings.

[0003] The present invention also relates to a beer, characterized in that the total dimethyl sulfide content is at least 50 µg / L, the difference between the total dimethyl sulfide content and the free dimethyl sulfide content is in the range of 40-250 µg / L, and the thiobarbituric acid value is 16-33. Background Technology

[0004] Fermented malt beverages (such as beer and whiskey) are produced by methods that typically include the following steps: • Prepare an aqueous malt mixture containing water and malt; • Malt paste is prepared by saccharifying the aqueous malt mixture; • Separate the malt pulp into wort and malt residue; • Boil the wort; • Cooling the boiled wort to a temperature below 30°C produces cooled wort; and • Fermenting cooled wort with active yeast.

[0005] In conventional beer production, wort boiling is a key process step with multiple functions, including: • Inactivates enzymes • Sterilization • Causes protein coagulation and precipitation. • Sugar is concentrated through evaporation. • Isomerize alpha acids derived from hops. • Convert S-methylmethionine to dimethyl sulfide. • Remove unwanted volatile flavor components.

[0006] During wort boiling, two main processes can be distinguished: heat preservation and evaporation. During heat preservation, various chemical reactions occur, such as hop isomerization, the formation of aroma and color compounds, enzyme inactivation, protein coagulation, and sterilization. On the other hand, evaporation is used to remove undesirable aroma compounds, especially dimethyl sulfide (DMS).

[0007] DMS is a malt-derived flavor compound with an extremely low flavor threshold of 40-60 ppb, produced through the thermal decomposition of S-methylmethionine (SMM). DMS formed during wort boiling is rapidly lost through evaporation, but SMM continues to decompose during wort cooling, and the resulting DMS continues to enter the beer. To minimize this DMS formation, it is recommended to use malts with low SMM content and extend the wort boiling time to decompose most of the precursors and remove DMS. DMS is highly undesirable because it contributes to unpleasant tastes and aromas in the final beer.

[0008] Following the boiling stage of the wort, a process known as hot coagulant separation typically occurs, for example, in a vortex. Typically, prior to hot coagulant separation, the wort is cooled to a temperature below 90°C. This cooling can be achieved using a heat exchanger or a flash evaporator.

[0009] As society becomes increasingly aware of the environmental impact of human activities, there is a growing emphasis on developing more sustainable and energy-efficient production processes. Since wort boiling is one of the most energy-intensive processes in breweries, there is a strong desire to replace it with more energy-efficient alternatives.

[0010] Desobgo ( The worst boiling techniques and energy requirements: A Review [Wort Boiling Technology and Energy Requirements: An Overview] The 1 stThe International Conference on Local Resource Exploitation (1st edition), Ngaoundere, Cameroon (2021), 939-956, provides a review of different wort boiling technologies and estimates the specific energy requirements of each technology. This article discusses the wort boiling technology introduced by Maule and Clark in 1985, in which the wort is heated to 93°C. It also discusses the vacuum boiling system (300 mbar, 69°C) introduced by Kaspar Schulz (Bamberg, Germany).

[0011] EP-A 3 760 700 describes a method for treating a wort composition in a reactor, the method comprising the following steps: (a) Provide a vessel equipped with a gas bubbling system; (b) Add the wort from the wort separation step to the kettle; (c) Heat the wort to a target temperature between 80°C and 96°C; (d) Maintaining the average target temperature between 80°C and 96°C for a period of 12-45 minutes, during which gas bubbling occurs at a rate of less than 10 g / hL / h, preferably without gas bubbling. (e) Raise the temperature of the wort composition to a target temperature between 97°C and 99°C; (f) Bubbling gas through the wort composition at an average rate of 80-350 g / hl / h, while maintaining an average target temperature between 97°C and 99°C for a period between 15 and 75 minutes; and during this period, the wort composition does not reach its boiling point; and (g) Transfer the treated wort composition to the coagulant separation step.

[0012] WO 2015 / 067737 relates to a method for treating wort in a reactor, the method comprising the steps of: (a) Provided: a vessel equipped with a gas bubbling system suitable for bubbling an inert gas into the wort, (b) The wort from the filtration step is fed into the boiling kettle, the wort being at a temperature below its boiling temperature; (c) When bubbling inert gas through the wort, the wort is heated to a temperature below the boiling point T of the wort. b Processing temperature T aThe wort is then maintained at the processing temperature for a duration t consisting of 15 to 90 minutes and not longer than the time required to evaporate up to 4 wt.% of the water initially present in the wort. t ; (d) Transfer the treated wort to the coagulant separation step.

[0013] GB-A 2 280 908 describes a method for clarifying beverage brewings, which includes adding a mixture of linear sulfated polysaccharides and silica sol to brewing wort.

[0014] WO 2021 / 155258 describes a method for controlling off-flavors in low-alcohol beer, which includes: • Selected malted barley varieties are saccharified in a malt pulp conversion vessel to form malt pulp; • Separate the malt pulp to form wort; • Transfer the wort to the kettle; and • During the wort boiling process, a certain amount of tannins is added to the wort in the pot. The amount of tannic acid involved either precipitates precursors or inhibits reactions that lead to the formation of Strecker aldehydes in low-alcohol beer.

[0015] Dugulin et al. Brewing with 100% green malt - process development and Key quality indicators [Brewing with 100% green malt - Process development and key quality indicators] J. Inst. Brew. (2020); 126: 343-353) describes beers brewed using undried, malted (green) malt. Six green malt beers were brewed, meeting specifications for pH, alcohol content, foam stability, and color. No significant off-flavors or obvious defects were detected in the green malt beers. Increased levels of S-methylmethionine were measured in the wort and beer made from green malt; however, the concentration of DMS in the finished beer was not significantly different from that in the reference beer.

[0016] Schwill-Miedaner ( Worrying today - are there alternatives? [Bud sap boiling technology - are there alternatives?] According to Brauwelt International (2003), 21(1) 42-48), boiling wort accounts for an average of 33%-50% of the total heat demand of a brewery, and a large amount of energy (about 55% of primary energy) can be saved by taking measures such as reducing total evaporation and using heat recovery.

[0017] Hertel et al. Low temperature wort flavor evaporation: A new dimension In evaporation Efficiencies [Low-Temperature Wheat Wort Flavor Evaporation: A New Dimension of Evaporation Efficiency]Cerevisia (2011) 36 (11-16) reported that the gas-liquid balance of wort flavor components in wort can be affected by changing the evaporation temperature, and thus the efficiency of the evaporation process during beer production. According to the authors, there are significant advantages to evaporating unwanted flavors in the low-temperature zones of the brewery.

[0018] Willaert et al. Wort Boiling Today - Boiling Systems with Low Thermal Stress in Combination with Volatile Stripping [Modern wort boiling technology - with low heat] [Combination of stress-induced boiling system with volatile stripping] Cerevisia: Belgian Journal of Brewing and Biotechnology, 26(4) (2001) 217-230) discusses the objectives of wort boiling, the possibility of reducing the thermal stress of wort, and the environmental aspects of wort boiling. Summary of the Invention

[0019] The inventors have unexpectedly discovered that a high-quality fermented malt beverage can be produced through an energy-saving method, in which a mild heat treatment of the wort is used instead of the conventional boiling step, and an anionic flocculant is added to the wort before or during the mild heat treatment.

[0020] Therefore, a first aspect of the present invention relates to a method for producing a fermented malt beverage, the method comprising the following steps: a) Prepare an aqueous malt mixture containing water and malt; b) Prepare malt paste by saccharifying the aqueous malt mixture; c) Separate the malt pulp into wort and lees; d) Keep the wort at a temperature of at least 70°C for at least 5 minutes to produce heated wort; e) Cool the heated wort to a temperature below 30°C to produce cooled wort; and f) Contact the cooled wort with active yeast for at least 8 hours to produce fermented wort; Between steps c) and f), the temperature of the wort is maintained below 90°C, wherein boiling of the wort is avoided, wherein hot coagulants are 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 coagulants.

[0021] While the inventors do not wish to be bound by theory, it is believed that although the evaporation removal of dimethyl sulfide during the mild heat treatment of the wort in the method of the present invention is limited, the formation of dimethyl sulfide is effectively minimized due to the mild heating conditions. Therefore, even though the method of the present invention does not employ the conventional wort boiling step, the beer obtained by this method does not exhibit flavor defects associated with the presence of dimethyl sulfide. Furthermore, the addition of anionic flocculants to the wort effectively reduces the formation of off-flavor characteristics during wort heating and / or helps to remove off-flavor-generating components and thermal coagulation.

[0022] In the method of this invention, the heat load exposed to the fermented malt beverage is lower than that of conventional methods, resulting in a malt beverage with a relatively low thiobarbituric acid value and a relatively high S-methylmethionine content. Furthermore, by avoiding wort boiling, the formation of dimethyl sulfide from S-methylmethionine is inhibited. In other words, in the method of this invention, only a portion of the S-methylmethionine in the wort is converted to dimethyl sulfide. Therefore, the beer obtained by this invention is characterized by a low thiobarbituric acid value, extremely high S-methylmethionine content, and low dimethyl sulfide content.

[0023] Therefore, the present invention also provides a beer characterized in that the total dimethyl sulfide content is at least 50 µg / L, the difference between the total dimethyl sulfide content and the free dimethyl sulfide content is in the range of 40-250 µg / L, and the thiobarbituric acid value is 16-33. Detailed Implementation

[0024] This invention provides a method for producing fermented malt beverages, the method comprising the following steps: a) Prepare an aqueous malt mixture containing water and malt; b) Prepare malt paste by saccharifying the aqueous malt mixture; c) Separate the malt pulp into wort and lees; d) Keep the wort at a temperature of at least 70°C for at least 5 minutes to produce heated wort; e) Cool the heated wort to a temperature below 30°C to produce cooled wort; and f) Contact the cooled wort with active yeast at a temperature below 7°C for at least 8 hours to produce fermented wort; Between steps c) and f), the temperature of the wort is maintained below 90°C, wherein boiling of the wort is avoided, wherein hot coagulants are 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 coagulants.

[0025] Unless otherwise specified, the term "alcohol" as used herein refers to ethanol.

[0026] As used in this article, the term "malt" refers to malted grains, such as malted barley.

[0027] As used herein, the term "100% malt beer" refers to beer made solely from malt, i.e., without the use of any unmalted adjuncts (e.g., unmalted starch sources and / or syrups).

[0028] Unless otherwise stated, the term “or” as used herein shall be interpreted as “and / or”.

[0029] Unless otherwise stated, the term "a / an" as used herein is defined as "at least one / an".

[0030] As used herein, the term "isoalpha acid" refers to substances selected from the group consisting of isohumulone, isoadhumulone, isocohumulone, pro-isohumulone, post-isohumulone, and combinations thereof. The term "isoalpha acid" also encompasses different stereoisomers (cis-isoalpha acid and trans-isoalpha acid). Isoalpha acids are typically produced in beer by adding hops to boiled wort. They can also be introduced into beer in the form of pre-isomerized hop extracts. Isoalpha acids are very bitter at an estimated threshold of approximately 6 ppm in water.

[0031] The term "hydroisoacid" refers to substances selected from the following: dihydroisoacid, tetrahydroisoacid, hexahydroisoacid, and combinations thereof.

[0032] As used herein, the term "hulupone" refers to a selection of substances including cohulupone, n-hulupone, adhulupone, and combinations thereof. Hulupone is an oxidation product of hop β-acids.

[0033] As used herein, the term "gas" refers to an element, substance, mixture of elements, mixture of substances, or mixture of elements and substances that is in a gaseous state under the conditions employed in the methods of the present invention. Nitrogen, carbon dioxide, air, and vapor are examples of gases that can be used in the methods of the present invention.

[0034] The free dimethyl sulfide content in beer is equal to the concentration of dimethyl sulfide (DMS) present in the beer, as determined by HS-GC / MS using the method described by Stafisso et al. DETERMINATION OF DIMETHYL SULPHIDE IN BREWERY SAMPLES BY HEADSPACE GAS CHROMATOGRAPHY MASS SPECTROMETRY (HS-GC / MS) [Determination of dimethyl sulfide in brewery samples by headspace gas chromatography-mass spectrometry (HS-GC / MS)]Italian Journal of Food Science, January 2011, pp. 19-27.

[0035] The total dimethyl sulfide (DMS) content in beer is equal to the concentration of DMS present in the beer after the beer undergoes a treatment that quantitatively converts S-methylmethionine (SMM) to DMS, as described in the aforementioned paper by Stafisso et al. Therefore, the SMM content of beer in DMS equivalents can be calculated by subtracting the free DMS content from the total DMS content.

[0036] The fermented malt beverage produced by the method of the present invention is preferably beer, or even more preferably lager beer.

[0037] The malt used in the aqueous malt mixture in step a) is preferably selected from malted barley, malted sorghum, malted wheat, malted rye, and combinations thereof. Most preferably, the malt used is malted barley.

[0038] The aqueous malt mixture prepared in step a) of the method of the present invention may contain adjuvants in addition to water and malt. Preferably, the malt accounts for at least 10 wt.%, more preferably at least 30 wt.%, even more preferably at least 50 wt.%, and more preferably at least 60 wt.% of the dry matter present in the aqueous malt mixture.

[0039] According to another preferred embodiment, malt and unmalted grains together constitute at least 70 wt.%, more preferably at least 85 wt.%, of the dry matter present in the aqueous malt mixture. Even more preferably, all the dry matter in the aqueous malt mixture is provided by malt and unmalted grains. Most preferably, all the dry matter in the aqueous malt mixture is provided by malt.

[0040] In the saccharification step of the method of the present invention, enzymes present in the malt (especially amylases) are allowed to break down starch into fermentable sugars, such as maltose. The saccharification step can be suitably carried out as leaching saccharification or boiling saccharification.

[0041] During the preparation of malt paste in the method of the present invention, during the saccharification step b), the temperature of the aqueous malt mixture is preferably maintained below 95°C, more preferably below 90°C, and even more preferably below 85°C.

[0042] The saccharification step b) of the method of the present invention preferably includes heating the aqueous malt mixture to a temperature of at least 60°C, more preferably at least 65°C, and most preferably at least 70°C.

[0043] The separation of malt pulp into wort and spent grains can be suitably carried out in a solid-liquid separation apparatus. Examples of such solid-liquid separation apparatus include filter tanks, saccharification / filtration vessels, and saccharification filters.

[0044] Examples of anionic flocculants that can be used in the methods of the present invention include tannins, carrageenan, alginate, and combinations thereof.

[0045] According to 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 can be used as an anionic flocculant in the method of the invention.

[0046] According to 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 κ-carrageenan. Whirlfloc® is an example of κ-carrageenan that can be used as an anionic flocculant in the method of the invention.

[0047] According to a particularly preferred embodiment, the method of the present invention employs a combination of at least two anionic flocculants, including tannins and carrageenan, more preferably including tannic acid and κ-carrageenan.

[0048] The total amount of anionic flocculant added to the wort is preferably in the range of 0.5-20 g / hL wort, more preferably in the range of 1-15 g / hL wort, and most preferably in the range of 2-11 g / hL wort.

[0049] In the method of the present invention, the flocculant is preferably added before or during heating 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 heating step d).

[0050] Between steps c) and f) of the method of the present invention, the temperature of the wort is preferably maintained below 86°C, more preferably below 84°C, and most preferably below 82°C.

[0051] Preferably, the wort is kept at a temperature of at least 70°C for 10-100 minutes, more preferably 30-90 minutes, even more preferably 35-85 minutes, and most preferably 40-80 minutes.

[0052] According to a particularly preferred embodiment, the wort is kept at a temperature in the range of 73°C-85°C for at least 5 minutes, preferably 10-100 minutes, more preferably 30-90 minutes, even more preferably 35-85 minutes, and most preferably 40-80 minutes.

[0053] In step d), the retention of wort is preferably carried out at a pressure of at least 0.8 atm, more preferably at a pressure of 0.85-1.5 atm, and most preferably at a pressure of 0.9-1.2 atm.

[0054] The inventors unexpectedly discovered that bubbling the wort with gas during heating step d) improves the flavor of the final beverage. It is believed that bubbling the wort during the heat treatment facilitates protein coagulation and precipitation, as well as the removal of thermal coagulated material. As mentioned above, effective removal of thermal coagulated material is associated with a reduction in off-flavors in the final beverage.

[0055] Preferably, the gas bubbled through the wort in the method of the present invention 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 oxygen present in the air oxidizes precursors of volatile odor compounds. These volatile odors are then carried away by the bubbling gas. Therefore, wort obtained after bubbling with air has a significantly reduced content of oxidizable flavor precursors compared to wort without bubbling, and is less prone to developing off-odors after heating the wort.

[0056] In the method of the present invention, gas can be bubbled through the wort by introducing gas near the bottom of the container containing the wort and allowing the bubbles to travel upward through the wort.

[0057] In a preferred embodiment, gas is bubbled through the wort while it is kept at a temperature in the range of 72°C-86°C, more preferably in the range of 74°C-84°C, and most preferably in the range of 75°C-82°C.

[0058] When the wort is kept at a temperature within one of the above temperature ranges, the total amount of gas bubbled through the wort is preferably at least 20 g / hL of wort, more preferably 50 to 1,200 g / hL of wort, even more preferably 100 to 1,000 g / hL of wort, and most preferably 150 to 800 g / hL of wort.

[0059] In the method of the present invention, gas can be bubbled through the wort continuously or intermittently.

[0060] Preferably, the total time for the gas to bubble 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.

[0061] Preferably, the gas is bubbled through the wort at a rate in the range of 20 to 1,500 g / hl / h, more preferably in the range of 30 to 1,200 g / hl / h, even more preferably in the range of 40 to 900 g / hl / h, and most preferably in the range of 50 to 700 g / hl / h.

[0062] Hot coagulated material can be removed from heated wort using solid-liquid separation techniques known in the art. Preferably, the hot coagulated material is removed in a vortex.

[0063] When the heated wort has a temperature of at least 50°C, more preferably at least 70°C, the removal of thermal coagulated material is preferably carried out.

[0064] In a particularly preferred embodiment of the method according to the invention, the source of hop acids is preferably added to the wort before contacting 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 isoalpha acids, hydrogenated isoalpha acids, herrucones, and combinations thereof. More preferably, the source of hop acids is added to the wort in an amount providing 2 to 40 mg / L of hop acids, most preferably 3 to 30 mg / L of hop acids.

[0065] Preferably, the source of hop acid is an iso-alpha acid source, which is selected from isomerized hop extract, isomerized hop particles, and combinations thereof.

[0066] Preferably, the source of hop acid is added to the wort during step d) or during the removal of hot coagulant, especially during the removal of hot coagulant in a vortex.

[0067] In the method according to the invention, the wort is contacted with active yeast. The yeast is preferably selected from the genus *Saccharomyces* (*Saccharomyces*). Saccharomyces More preferably, it is selected from Pasteurella multocida ( Saccharomyces pastorianus ), grape juice yeast ( Saccharomyces uvarum ), brewer's yeast ( Saccharomyces cerevisiae ) and combinations or hybrids thereof, most preferably, the yeast is Pasteurella ( Saccharomyces pastorianus ).

[0068] The contact between the cooled wort and the active yeast preferably includes using at least 10 5 1 cell / mL yeast, preferably 3 x 10 5 -3 x 10 7 Yeast is inoculated at a rate of 1 cell / mL of wort. Typically, yeast is allowed to form a settling layer at the bottom of the container holding the inoculated, cooled wort, or a floating layer below the surface of the wort. Most preferably, yeast is allowed to form a settling layer at the bottom of the container.

[0069] The method of the present invention can be appropriately used to produce alcoholic fermented malt beverages and non-alcoholic fermented malt beverages.

[0070] In a preferred embodiment of the method of the present invention, cooled wort is contacted with active yeast at a temperature of 5°C to 40°C for at least 8 hours to produce an alcohol-containing fermented wort with an alcohol content of 3%-12% ABV, more preferably 4%-7% ABV. More preferably, cooled wort is contacted with active yeast at a temperature of 6°C to 30°C, most preferably 8°C to 15°C.

[0071] In an embodiment of the method of the present invention for producing alcohol-containing fermented wort, the cooled wort is preferably contacted with active yeast at the mentioned temperature for at least 20 hours, more preferably 50 to 600 hours, and even more preferably 100 to 400 hours.

[0072] In another preferred embodiment, the cooled wort is contacted with active yeast at a temperature below 7°C for at least 8 hours to produce an alcohol-free fermented wort with an alcohol content of less than 0.5% ABV, more preferably less than 0.1% ABV. More preferably, the cooled wort is contacted with active yeast at a temperature of -2°C to 5°C, most preferably -1°C to 4°C.

[0073] In embodiments of the method of the present invention used for the production of non-alcoholic fermented wort, the cooled wort is preferably contacted with active yeast at the mentioned temperature for at least 4 hours, more preferably 8 to 72 hours, and even more preferably 12 to 48 hours. This embodiment of the method of the present invention is particularly suitable for producing non-alcoholic fermented malt beverages using so-called cold contact fermentation. The non-alcoholic fermented malt beverages obtained by the method of the present invention contain almost no of the typical undesirable 'worty' flavor of non-alcoholic beverages produced by cold contact fermentation.

[0074] After contact with active yeast, the fermented wort can undergo one or more additional processing steps, such as conditioning, filtration, carbonation, and packaging (e.g., bottling or barrelling).

[0075] The present invention also relates to available fermented malt beverages, preferably fermented malt beverages obtained by the method of the present invention.

[0076] Another aspect of the present invention relates to a beer characterized by having a total dimethyl sulfide content of at least 50 µg / L, the difference between the total dimethyl sulfide content and the free dimethyl sulfide content being in the range of 40-250 µg / L, and a thiobarbituric acid value of 16-33.

[0077] Preferably, the beer of the present invention is available, and more preferably obtained by the method for preparing fermented malt beverages described above.

[0078] In one embodiment, the beer is an alcoholic beer with an alcohol content of 3%-12% ABV, preferably 4%-7% ABV.

[0079] In another embodiment, the beer is a non-alcoholic beer having an alcohol content of less than 0.5% ABV, preferably less than 0.1% ABV.

[0080] Non-alcoholic beer is preferably obtained through cold contact fermentation. Compared with non-alcoholic beer obtained by dealcoholization, non-alcoholic beer obtained by cold contact fermentation contains a significant amount of maltose. Therefore, the beer preferably contains at least 3 g / L, more preferably 5-40 g / L, and most preferably 8-25 g / L of maltose.

[0081] According to a particularly preferred embodiment, the beer of the present invention is a 100% malt beer.

[0082] 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.

[0083] The beer described herein differs from ordinary beer in that it is exposed to significantly less heat. The thiobarbituric acid value (TAN) of beer indicates the heat load exposed to the beer. According to a preferred embodiment, the beer according to the invention has a TAN of less than 30, more preferably less than 26, even more preferably 18 to 24, and most preferably 19 to 22. The TAN of beer can be determined by spectrophotometry, as described in [the relevant documentation]. Manual, Analysis Methods for the Brewery Industry [Beer Industry Analysis Methods Handbook] Spectroquant® Prove, July 2017 edition, pp. 101-103.

[0084] The total dimethyl sulfide content of the beer of the present invention is preferably in the range of 80-300 µg / L, more preferably in the range of 100-270 µg / L, even more preferably in the range of 120-250 µg / L, and most preferably in the range of 140-230 µg / L.

[0085] The free dimethyl sulfide content of the beer is preferably in the range of 10-200 µg / L, more preferably in the range of 20-160 µg / L, and most preferably in the range of 30-140 µg / L.

[0086] The beer of the present invention is characterized by a relatively low fraction of free dimethyl sulfide in the total dimethyl sulfide content of the beer. Preferably, the free dimethyl sulfide accounts for at most 70% of the total dimethyl sulfide content, more preferably 10%-65%, even more preferably 15%-60%, and most preferably 20%-55%.

[0087] The difference between the total dimethyl sulfide content and the free dimethyl sulfide content indicates the S-methylmethionine content of beer. For the beer according to the invention, the difference between the total dimethyl sulfide content and the free dimethyl sulfide content is preferably in the range of 40-250 µg / L, more preferably in the range of 60-190 µg / L, and most preferably in the range of 70-140 µg / L.

[0088] According to a particularly preferred embodiment, the beer of the present invention contains hop acids that provide bitterness. 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, herrucones, and combinations thereof.

[0089] 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-α-acid.

[0090] The beer preferably has a free amino nitrogen (FAN) content of 40 to 150 mg / L, more preferably 50 to 130 mg / L, and most preferably 60 to 100 mg / L. The FAN content of the beer can be suitably determined using EBC method 9.10.1.

[0091] The beer preferably contains at least 0.2 µg of total dimethyl sulfide per mg FAN, more preferably 0.4-5 µg of total dimethyl sulfide, even more preferably 0.5-4 µg of total dimethyl sulfide, and most preferably 0.6-3 µg of total dimethyl sulfide.

[0092] The TAN (Total Anti-Alcoholic Acid) of beer is affected by the degree of dilution that occurs after the production of heated wort. For example, non-alcoholic beer produced by cold contact fermentation can be significantly diluted after the fermentation step to reduce sweetness. The TAN of beer is also affected by the use of adjuncts. Both dilution and the use of adjuncts lead to a decrease in TAN and a decrease in FAN. According to a preferred embodiment, the TAN and FAN of the beer of the present invention satisfy the following condition: TAN ≤ 0.35xFAN, where FAN is expressed in mg / L. More preferably, the beer satisfies the condition TAN ≤ 0.28xFAN, and most preferably the beer satisfies the condition TAN ≤ 0.25xFAN.

[0093] The invention is further illustrated by the following non-limiting examples.

[0094] Example Example 1 Prepare malt pulp as follows: • Combine ground barley malt and water at a weight ratio of 1:3 at 60°C. • Adjust the pH to 5.6 using HCl solution. • Add calcium chloride to increase the calcium content to 159 ppm.

[0095] • Saccharification at 60°C within 10 minutes • Let the protein rest at 60°C for 5 minutes. • Heat to 66°C within 12 minutes • Saccharification rest at 66°C for 25 minutes • Heat to 76°C within 10 minutes • Allow 5 minutes for saccharification at 76°C. The malt pulp is filtered through a malt pulp filter to produce a certain amount of wasps and a separate wort stream. The pH of the wort is then adjusted to 5.2 (HCl or KOH).

[0096] The wort thus obtained was divided into 5 different volumes, and these different volumes of wort were subjected to different heating schemes with and without the addition of anionic flocculant, as shown in Table 1. In all cases, 7.85 g / hl of IKE (58.8% iso-α acid) was added 15 minutes before the end of the heating step.

[0097] Table 1

[0098] 1 Ajinomoto OmniChem NV, Belgium - Add at the start of the heating step 2 KERRY, Ireland - Add 15 minutes before the heating step is finished Transfer all five wort portions to vortex containers and let stand for 10 minutes, then cool them to 8°C. Aerate the wort with 44 ppm oxygen and place it in a fermenter, adding 350 g / hl of yeast (100% consistency). Adjust the zinc concentration to 0.5 mg / l. Fermentation is carried out at 10°C, and when the extract reaches 7 Plato degrees (°Plato), the temperature is raised to a maximum of 14°C.

[0099] Once the diacetyl level is below 15 ppb, the fermented wort is deeply cooled and held at -1°C for several days. Next, 30 g / hl of PVPP is added, followed by filtration through a beer membrane filter. The final product is normalized to 5% ABV, 5.2 g / l CO2, 20 BU bitterness, and 7 EBC color.

[0100] The resulting beers were then evaluated blinded by a panel of experts. Beer made from wort A was rated 'unacceptable'. All other beers were rated 'acceptable' to 'good'. Beer made from boiled wort was superior to the other beers. Beer made from wort D was superior to beer made from wort A, wort B, and wort C.

[0101] Example 2 As described in Example 1, two non-alcoholic beers were prepared from wort B. During heating, one of the two worts was bubbled with air at a flow rate of 7.7 liters / hc / min (596 g / hl / h).

[0102] The resulting beer was then evaluated by a blind panel of experts. Beer made from wort that had been bubbled with air tasted better.

Claims

1. A method for producing a fermented malt beverage, the method comprising the following steps: a) Prepare an aqueous malt mixture containing water and malt; b) Prepare malt paste by saccharifying the aqueous malt mixture; c) Separate the malt pulp into wort and malt residue; d) The wort is kept at a temperature of at least 70°C for at least 5 minutes to produce heated wort; e) Cool the heated wort to a temperature of less than 30°C to produce cooled wort; as well as f) Contact the cooled wort with active yeast for at least 8 hours to produce fermented wort; Between steps c) and f), the temperature of the wort is maintained below 90°C; wherein boiling of the wort is avoided. The hot coagulant is removed from the heated wort before step f); and an anionic flocculant is added to the wort before the hot coagulant is removed.

2. The method according to claim 1, wherein, The anionic flocculant is tannin, preferably tannic acid.

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

4. The method according to claim 3, wherein, The anionic flocculant is κ-carrageenan.

5. The method according to any one of the preceding claims, wherein, Add 0.5-20 grams of flocculant per 100 liters of wort.

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

7. The method according to any one of the preceding claims, wherein, During at least a portion of a time period in which the wort is kept at a temperature of at least 70°C, gas is bubbled through the wort.

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

9. The method according to any one of the preceding claims, wherein, The wort is maintained at a pressure of at least 0.8 atm.

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

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

12. The method according to any one of the preceding claims, wherein, The contact between the cooled wort and active yeast produces fermented wort with an ethanol content of at least 3% ABV.

13. A beer, characterized in that, The total dimethyl sulfide content is at least 50 µg / L, the difference between the total dimethyl sulfide content and the free dimethyl sulfide content is in the range of 40-250 µg / L, and the thiobarbituric acid value is less than 33.

14. The beer according to claim 13, wherein, Free dimethyl sulfide accounts for up to 35% of the total dimethyl sulfide content.

15. The 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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