Energy efficient process for the production of lager beer

Abstract

The invention relates to a process of producing a lager beer that comprises the following steps: a) preparing an aqueous malt mixture comprising water and chit malt, wherein the chit malt provides 30-100 wt.% of the dry matter that is contained in the aqueous malt mixture; 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 ⁰C for a time period of at least 12 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 a source of hop acids is added to the wort before the contacting of the cooled wort with active yeast, wherein the temperature of the wort is maintained below 90 ⁰C between steps c) and f); and wherein boiling of the wort is avoided. Good quality flagger beers can be produced by this energy efficient process in which at least a part of the malt is replaced by chit malt and wherein the conventional wort boiling step is replaced by a mild heat treatment of the wort.

Description

Technical field of the invention The invention provides an energy efficient process for the production of a lager beer, the process comprising: a) preparing an aqueous malt mixture comprising water and chit malt, wherein the chit malt provides 30-100 wt.% of the dry matter that is contained in the aqueous malt mixture; 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 12 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 a source of hop acids is added to the wort before the contacting of the cooled wort with active yeast, wherein the temperature of the wort is maintained below 90 °C between steps c) and f); and wherein boiling of the wort is avoided. The process according to the present invention yields lager beers of high quality whilst at the same time achieving significant energy savings compared to existing processes for the production of lager beer. Background of the invention Malt is germinated cereal grain that has been produced in a process known as “malting”. Malting is a process of steeping, germinating, drying and deculming grain to convert it into malt. The main purpose of the malting process is to develop the endogenous enzymes a-amylase and p-amylase. These enzymes catalyse the conversion of starch into fermentable sugars when malt is used to produce a wort, i.e. the liquid extracted from the mashing process during the brewing of beer or whisky. Various grains are used for malting; the most common are barley, sorghum, wheat and rye. The malted grains obtained by malting barley or rye still contain the outer husk. Steeping is the start of the malting process and comprises the addition of steep water to cover the grain to increase the moisture content of the grain to between 40 and 45%. In a modern pneumatic malt house, the grain is alternatively submerged (wet stand) and then drained (an air rest) for one, two or three cycles to achieve the target grain moisture content and the desired chit count. The chit is the first sign of the emerging rootlets. At the end of steeping the grain is cast-out to germination. The aim of germination is to sprout the grains. During sprouting, malt enzymes are activated and these enzymes start modifying the structure of the barley endosperm by breaking down the cell walls and the protein matrix. Germination produces a large amount of heat. The grain bed is maintained at a constant temperature of between 10 and 16 °C by the constant supply of fresh humidified air and turners move through the grain bed to keep it loose to allow for sufficient air-flow. Germination typically takes 4-6 days and results in what is called “green malt”. Kilning reduces the grain moisture content of the green malt and stops the germination process. In the first stage, the free drying stage, the air temperature is kept cool to dry the grain without causing the enzymes to denature. As the grain dries it is possible to raise the air temperature (the second stage or the forced drying stage) to further dry the grain without inactivating the amylase enzymes. The target malt moisture after kilning is around 5% by weight. During the last few hours of kilning the air temperature is raised to above 80 °C (the curing stage). At the final drying stage colour and the malty aroma are formed by Maillard reactions. Deculming is the term used for the removal of rootlets of the malt. Deculming is normally carried out shortly after transfer from the kiln. “Chit malt” is a special type of malt that differs from ordinary malt in that it is obtained by a process that employs a shortened germination period of typically 1-2 days. In comparison to ordinary malt, the alpha-amylase activity of chit malt is considerably lower. Whereas ordinary malt typically has an alpha-amylase activity (EBC 4.13) of around 64 dextrinising unites (DU) per gram of dry matter, chit malt obtained after 1 day of germination typically has an alpha amylase activity of less than 58 DU per gram of dry matter. Fermented malt beverages such as beerand whiskey are produced by a process that typically comprises the following steps: • preparing an aqueous malt mixture comprising water and malt; • preparing a mash by mashing the aqueous malt mixture; • separating the mash into wort and spent grain; • boiling the wort; • cooling the boiled wort to a temperature of less than 30°C to produce a cooled wort; and • fermenting the cooled wort with active yeast. In the conventional production of beer, wort boiling is a critical process step that serves multiple purposes, including: • inactivation of enzymes, • sterilization, • coagulation and precipitation of proteins, • concentration of sugars through evaporation, • isomerization of a-acids from hops, • conversion of S-methylmethionine into dimethyl sulphide, • removal of unwanted volatile flavour components. 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). 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. As society becomes more conscious about the impact of human activities on the environment, there has been a growing emphasis on the development 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. Desobgo (The wort boiling techniques and energy requirements: A Review, The 1st International 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). EP-A 3 760 700 describes a process for treating a wort composition in a kettle, the process comprising the steps of: (a) providing a kettle provided with a gas sparging system; (b) adding wort from a mash separating step into said kettle; (c) heating said wort to a target temperature between 80 and 96°C; (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; (e) raising the temperature of the wort composition to a target temperature of between 97°C and 99°C; (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 (g) transferring the treated wort composition to a trub separation step. WO 2015 / 067737 concerns a process for treating a wort in a kettle, said method comprising the steps of: (a) providing: a kettle provided with a gas sparging system suitable for sparging an inert gas into said wort, (b) feeding wort from a lautering step into said boiling kettle, said wort being at a temperature below its boiling temperature; (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, Tb, 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. US 2011 / 274785 describes a method for producing a malt beverage, comprising: • obtaining a mixture comprising water and milled malt to produce a primary mash; • producing wort from the primary mash; • obtaining a supernatant liquid comprising active enzymes from a secondary mash; and • adding the supernatant liquid from the secondary mash to the wort WO 2023 / 214077 describes method of producing a malt beverage, said method comprising: • providing a mixture comprising malt and water, wherein at least 1 wt.% of the malt is a peeled chit malt; • mashing the mixture to convert starch into fermentable sugars and to produce a mash containing fermentable sugars; and • subjecting the mash containing fermentable sugars to a solid-liquid separation to separate wort from insoluble matter. In a blog, posted by Andreas Krennmair, dated June 2, 2019, a description is provided of the brewing of ‘Berliner Weisse’. The grist used contained 2 kg pale wheat malt, 1 kg chit malt and 0.5 kg Bohemian pilsner malt. Hops were added during mashing. After lautering and sparging, 20 liters of wort was collected and brought up to 80°C to pasteurise it for 10 minutes, following which the wort was chilled and pitched with yeast and bacteria. Summary of the invention The inventors have unexpectedly discovered that good quality lager beers can be produced by an energy efficient process in which at least a part of the malt is replaced by chit malt and wherein the conventional wort boiling step is replaced by a mild heat treatment of the wort. Accordingly, a first aspect of the invention relates to a process of producing a lager beer that comprises the following steps: a) preparing an aqueous malt mixture comprising water and chit malt, wherein the chit malt provides 30-100 wt.% of the dry matter that is contained in the aqueous malt mixture, said chit malt being malted cereal grain that has been obtained after a germination period of 15-48 hours, during which germination period at least 90% of the grains has developed a visible chit; 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 a source of hop acids is added to the wort before the contacting of the cooled wort with active yeast, wherein the temperature of the wort is maintained below 90 °C between steps c) and f); and wherein boiling of the wort is avoided. In conventional beer production, production of the malt and the wort boiling step together are responsible for most of the energy consumption (excluding energy needed for the production of the grain and hops). The present process substantially reduces the energy consumption of these two process steps. Furthermore, although in the present process evaporative removal of dimethyl sulphide (DMS) during the mild heat treatment of the wort is limited, it is believed that due to the mild heating conditions, formation of DMS 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 DMS. Detailed description of the invention The present invention provides a process of producing a lager beer that comprises the following steps: a) preparing an aqueous malt mixture comprising water and chit malt, wherein the chit malt provides 30-100 wt.% of the dry matter that is contained in the aqueous malt mixture, said chit malt being malted cereal grain that has been obtained after a germination period of 15-48 hours, during which germination period at least 90% of the grains has developed a visible chit; 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 12 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 a source of hop acids is added to the wort before the contacting of the cooled wort with the active yeast; wherein the temperature of the wort is maintained below 90 °C between steps c) and f), and wherein boiling of the wort is avoided. The term “barley” as used herein refers to husk-carrying grains from the species Hordeum vulgare. Husk-free or "naked" barley (Hordeum vulgare L. var. nudum) is not encompassed by the term “barley” as used herein. The term “malt” as used herein refers to malted cereal grain that has been obtained after a germination period of more than 2 days. The term “chit malt” as used herein refers to malted cereal grain that has been obtained after a germination period of 15-48 hours, at least 90% of the grains having developed a visible ‘chit’ during said germination period. The term “adjunct” as used herein refers to an ingredient other than malt that contains, by weight of dry matter, at least 50 wt.% of starch, maltodextrin, fermentable sugars and combinations thereof. The adjunct may be applied in the form a dry product or a liquid product. Syrups, such as maltose syrup and glucose syrup, are examples of liquid adjuncts. The term “steeping” as used herein refers to a procedure in which grains are covered with steep water to increase the moisture content of the grain (‘wet stand’). The wet stands may be interrupted by so called ‘dry stands’, during which the water is drained out and fresh air may be supplied to remove excess carbon dioxide. The term “germinating” as used herein refers to the procedure in which a bed of steeped grains is allowed to germinate under humid conditions. The term “beer” as used herein refers to a yeast fermented malt beverage that has been hopped. Beer is conventionally produced by a process that comprises the following basic steps: • mashing a mixture comprising malted grains, preferably malted barley, optionally supplementary grains and water to produce a mash; • separating the mash in wort and spent grains; • boiling the wort to produce a boiled wort; • fermenting the boiled wort with live yeast to produce a fermented wort; • subjecting the fermented wort to one or more further process steps (e.g. maturation and filtration) to produce beer; and • packaging the beer in a sealed container, e.g. a bottle, can or keg. The term “alcohol” as used herein refers to ethanol, unless indicated otherwise. 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. 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. 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. Whenever reference is made herein to a standard method, such as an EBC method, the standard method meant is the last version of the standard method that was published before the filing date of this application. 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. The chit malt that is applied in the aqueous malt mixture of step a) preferably is produced from a grain selected from barley, sorghum, wheat, rye and combinations thereof. Most preferably, the chit malt is produced from barley. Malt preferably provides 0-70 wt.% of the dry matter that is contained in the aqueous malt mixture. The combination of chit malt and malt preferably provides 60-100 wt.%, more preferably 80100 wt.% of the dry matter that is contained in the aqueous malt mixture. Adjunct preferably provides 0-70 wt.%, more preferably 0-50 wt.% of the dry matter that is contained in the aqueous malt mixture. The adjunct that is employed in the present process is preferably selected from unmalted cereal grain, starch, maltodextrin, fermentable sugar and combinations thereof. More preferably, the adjunct is unmalted cereal grain. Most preferably, the adjunct is unmalted cereal grain selected from unmalted rice, unmalted corn, unmalted barley, unmalted rye, unmalted oats, unmalted wheat, unmalted sorghum and combinations thereof. The chit malt preferably has an extract content of 70-86% by weight of dry matter, more preferably of 72-84% by weight of dry matter and most preferably of 74-82% by weight of dry matter, as determined by EBC method 6.4. The chit malt preferably has an alpha-amylase activity of less than 55, more preferably 1-50, even more preferably 2-35, yet more preferably of 3-32, and most preferably of 4-30 Dextrinizing Units (DU) per gram of dry matter as determined by EBC method 4.13. The present process may be used to produce a lager beer in which chit malt is the only source of fermentable sugars that is employed in the process. Alternatively, besides chit malt, (ordinary) malt and / or adjuncts may be employed. The process of the present invention encompasses different embodiments in which a combination of chit malt and malt is employed. In one embodiment, both chit malt and malt are applied in the aqueous malt mixture. In accordance with this embodiment, besides water and chit malt, the aqueous malt mixture that is prepared in step a) of the present process also contains malt. In an alternative embodiment that employs both chit malt and malt, beside the preparation of a first wort from an aqueous malt mixture comprising water and chit malt, the process comprises separate preparation of a second wort by mashing an aqueous mixture of water and malt. In accordance with this embodiment, the process additionally comprises the steps of: • preparing a second aqueous malt mixture comprising water and malt; • preparing a second mash by mashing the second aqueous malt mixture; and • separating the second mash into a second wort and spent grain, • combining the second wort with the wort that is obtained from step a) to c). The two separately prepared worts may suitably be combined before the contacting with active yeast in step f) of the process. Alternatively, each of the two separately prepared worts are separately cooled and contacted with active yeast before being combined. According to a preferred embodiment, the first wort is prepared from an aqueous malt mixture that contains chit malt, but no malt, and the second wort is prepared from an aqueous mixture of water and malt that does not contain chit malt. In case the present process employs a combination of chit malt and malt, chit malt and malt are preferably employed in a dry weight ratio chit malt: malt of 1:4 to 9:1, more preferably of 1:3 to 4:1, most preferably of 1:2 to 3:1. In an embodiment in which the present process employs a combination of chit malt and adjunct, the combination of chit malt and adjunct preferably provides at least 50%, more preferably at least 60% and most preferably at least 70% of the dry matter that is provided by the combination of chit malt and adjunct. According to a preferred embodiment, chit malt, malt and unmalted cereal grain together provide at least 70 wt.% more preferably at least 85 wt.% and most preferably 100 wt.% of the dry matter that is provided by the combination of chit malt, malt and adjunct. The malt that is applied in the present process preferably is selected from malted barley, malted sorghum, malted wheat, malted rye and combinations thereof. Most preferably, the malt employed is malted barley. The malt preferably has an extract content of 74-86% by weight of dry matter, more preferably of 75-85% by weight of dry matter and most preferably of 76-83% by weight of dry matter, as determined by EBC method 4.5.1. The alpha-amylase activity of the malt preferably is at least 58 DU per gram of dry matter, more preferably in the range of 60-120 DU per gram of dry matter and most preferably in the range of 62-100 DU per gram of dry matter, as determined by EBC method 4.13 In the mashing step of the present process, enzymes (notably amylases) are allowed to break down starch into fermentable sugars, such as maltose. These enzymes may be provided by the chit malt, by malt or they may be added in the form of an enzyme preparation. The mashing step may suitably be carried out as an infusion mashing or a decoction mashing. 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). 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. 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. 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. Preferably, the wort is held at a temperature in the range of 70-90 °C for 7-100 minutes, more preferably for 8-45 minutes, even more preferably for 10-30 minutes, and most preferably for 12-25 minutes. 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 7-100 minutes, more preferably for 845 minutes, even more preferably for 10-30 minutes, and most preferably for 12-25 minutes. 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. 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. Preferably, the source of hop acids is a source of iso-alpha acids selected from isomerised hop extract, isomerised hop pellets and combinations thereof. 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. 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. The contacting of the cooled wort with active yeast preferably comprises inoculation of the wort with at least 105 cells / mL of yeast, preferably of 3x105-3x107 cells / 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. The present process may suitably be used to produce alcoholic as well as non-alcoholic lager beers. 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. 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. 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. 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 lager beers using so-called cold contact fermentation. The undesirable ‘worty’ flavour that is typical of non-alcoholic beers that have been produced by cold contact fermentation is virtually absent in the non-alcoholic lager beers obtained by the present process. 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). The present invention also pertains to lager beers that are obtainable, preferably lager beers that are obtained by the present process. The invention is further illustrated by the following non-limiting examples. Examples Example 1 A first mash (Mash 1) 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 A second mash (Mash 2) was prepared as follows: • ground chit malt and water were combined in a weight ratio of 1:3 at 50 °C • calcium chloride was added to increase calcium content to 164 ppm. • mashing in at 50 °C in 15 minutes • an enzyme mixture (alpha-amylase, beta-glucoamylase, xylanase, beta-glucanase, protease and lipase) was added pH was adjusted to 5.5 with HCI solution protein rest at 50 °C for 45 minutes heating to 65 °C in 15 minutes saccharification rest 1 at 65 °C for 45 minutes heating to 72 °C in 7 minutes saccharification rest 2 at 72 °C for 15 minutes heating to 78 °C in 10 minutes mashing off rest at 78 °C for 15 minutes The characteristics of the malt and chit malt are shown in Table 1. Table 1 Malt Chit malt Alpha-amylase activity (EBC 4.13) 55 15 Extract content (EBC 6.4 for chit malt) 82.4 78.2 Colour value (EBC 4.7.2) 4 2 Moisture content (EPC 4.2) 4.5 5.5 Both mashes were 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). The wort obtained from Mash 1 was separated into 2 fractions of equal size. The first fraction (Wort 1) was boiled for 60 minutes. Isomerised kettle extract (58.8% iso-alpha acids) was added (5.88g / hl) 15 minutes before the end of the heating step. The second fraction (Wort 2) was treated in the same way as Wort 1, except that it was heated to 80°C for 15 minutes. The wort obtained from Mash 2 (Wort 3) was treated in the same way as Wort 2. All three worts were transferred to a whirlpool vessel, where hop pellets type 90 (Tettnang saphir, BarthHaas) were added (90.6 g / hl). Next, the worts were subjected to a rest of 10 minutes before cooling of the worts to 8 °C. Next, Gistex LS Ferm (DSM) was dosed at 50 g / hl. The worts were aerated with 45 ppm oxygen and transferred to 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. The beers so obtained were blindly evaluated by an expert panel. The beer made from Wort 2 (Beer 2) was rated as ‘unacceptable’. The beer made from Wort 1 (Beer 1) was rated as ‘good’, and the beer made from Wort 3 (Beer 3) was rated as ‘acceptable’. These results demonstrate that the quality of beer that is produced by a process in which wort boiling is replaced by a less energy consuming mild heat treatment can be improved by replacing at least a part of the malt with chit malt. Example 2 Example 1 is repeated to produce Beer 1 and Beer 3. A third beer (Beer 4) is produced by mixing Beer 1 and Beer 3 in a 1:1 ratio. Blind evaluation of the three beers by an expert panel shows that Beers 1 and 4 are preferred over Beer 3.

Claims

1. A process of producing a lager beer, said process comprising the following steps:a) preparing an aqueous malt mixture comprising water and chit malt, wherein the chit malt provides 30-100 wt.% of the dry matter that is contained in the aqueous malt mixture, said chit malt being malted cereal grain that has been obtained after a germination period of 15-48 hours, during which germination period at least 90% of the grains has developed a visible chit;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 12 minutes to produce a heated wort;e) cooling the heated wort to a temperature of less than 30°C to produce a cooled wort; andf) contacting the cooled wort with active yeast for at least 8 hours to produce a fermented wort;wherein a source of hop acids is added to the wort before the contacting of the cooled wort with active yeast,wherein the temperature of the wort is maintained below 90 °C between steps c) and f), and wherein boiling of the wort is avoided.

2. Process according to claim 1, wherein the chit malt is produced from a grain selected from barley, sorghum, wheat, rye and combinations thereof.

3. Process according to claim 1 or 2, wherein malt provides 0-85 wt.% of the dry matter that is contained in the aqueous malt mixture, said malt being a malted cereal grain that is obtained after a germination period of more than 2 days.

4. Process according to any one of the preceding claims, wherein the combination of chit malt and malt provides at least 60 wt.%, preferably at least 80 wt.% of the dry matter that is contained in the aqueous malt mixture.

5. Process according to any one of the preceding claims, wherein chit malt is the only source of starch present in the aqueous malt mixture, or wherein the combination of chit malt and malt is the only source of starch present in the aqueous malt mixture.

6. Process according to claim 4, wherein chit malt is the only source of starch present in the aqueous malt mixture and wherein the process additionally comprises the steps of:• preparing a second aqueous malt mixture comprising water and malt;• preparing a second mash by mashing the second aqueous malt mixture; and• separating the second mash into a second wort and spent grain;• combining the second wort with the wort that is obtained from step a) to c).

7. Process according to any one of the preceding claims, wherein the chit malt has an alpha-amylase activity of less than 58 Dextrinizing Units (DU) per gram of dry matter.

8. Process according to any one of the preceding claims, wherein the aqueous malt mixture is heated to a temperature of at least 60 °C during mashing step b).

9. Process according to any one of the preceding claims, wherein the temperature of the aqueous malt mixture is maintained below 90°C during the mashing step b).

10. 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.

11. Process according to any one of the preceding claims, wherein the wort is held at a temperature in the range of 70-90°C for up to 100 minutes.

12. Process according to claim 8, wherein the wort is held at a temperature in the range of 73-85°C for 10-100 minutes.

13. Process according to any one of the preceding claims, wherein the wort is maintained at a temperature below 86 °C between steps c) and f).

14. Process according to any one of the preceding claims, wherein the source of hop acids is added to the wort in an amount providing 1 to 80 mg / L of hop acids selected from isoalpha acids, hydrogenated iso-alpha acids, hulupones and combinations thereof.

15. Process according to any one of the preceding claims, wherein he source of hop acids is a source of iso-alpha acids selected from isomerised hop extract, isomerised hop pellets and combinations thereof.

16. 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.

17. Process according to any one of the preceding claims, wherein 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.

18. A lager beer that is obtained by a process according to any one of the preceding claims.