Continuous production of dry malt grain

Abstract

The present invention provides a continuous process for the production of dry malt grain, the process comprising: providing a continuous flow of soaked grain having a water content of at least 30 wt.%; -passing the stream of soaked cereals through a germination stage to produce a continuous stream of malt cereals, said germination stage comprising: (i) maintaining the temperature of the cereals in the range of 10 DEG C to 30 DEG C, and (ii) maintaining the water content of the cereals in the range of 20 wt.% to 38 wt.%, the residence time of the grains in the germination stage is in the range of 12 to 36 hours; -conveying the layers of malt grains through a drying stage with a second mobile conveyor to produce a continuous flow of dry malt grains, the grains residing in the drying stage for a time in the range of 2 to 24 hours. The continuous production of the dry malt grain according to the present invention requires much less energy, time and water than conventional production methods. The invention also provides a dry malt barley obtained by the above method, said dry malt barley having the following combination of features:-alpha-amylase activity of 1-58 dextrinization units (DU) per gram of dry matter; a moisture content of 6.0 wt.% to 8.0 wt.%; wherein at least 95% of the cereals in the dry malt barley have a moisture content that does not exceed 1.0 wt.% from the moisture content of the dry malt cereals.

Description

Technical Field

[0001] The present invention relates to a continuous process for producing dry malt cereals, the process comprising:

[0002] a) providing a continuous flow of soaked grains;

[0003] b) conveying the stream of steeped grains through a germination stage to produce a continuous stream of malted grains; and

[0004] c) conveying the stream of malted grains through a drying stage using a second mobile conveyor to produce a continuous stream of dried malted grains.

[0005] The present invention further provides a short malt which has been very uniformly processed, resulting in a short malt having both a relatively high moisture content and excellent stability. Background of the Invention

[0007] Malt is germinated cereal grain produced in a process called "malting".

[0008] Malting is the process of soaking, germinating, drying and derooting the grains to convert them into malt. The main purpose of the malting process is to develop the endogenous enzymes alpha-amylase and beta-amylase. These enzymes catalyze the conversion of starch into fermentable sugars when the malt is used to produce wort (i.e. the liquid extracted from the mashing process during the brewing of beer or whiskey). Various grains are used for malting; the most common are barley, sorghum, wheat and rye. The malted grains obtained by germinating barley or rye kernels still contain the husk.

[0009] Steeping is the beginning of the kernel germination process and involves adding steepwater to cover the grain to increase the moisture content of the grain to between 44% and 46%. In a modern pneumatic malt house, the grain is alternately soaked (wet rest) and then drained (air rest) for one, two or three cycles to achieve the target grain moisture content and desired sprout count. Sprouts are the first sign of rootlet germination. At the end of the steeping, the grain is soaked for germination.

[0010] The purpose of germination is to germinate the grain. During germination, maltase is activated and these enzymes begin to modify the structure of the barley endosperm by breaking down the cell walls and protein matrix. Germination generates a large amount of heat. The grain bed is maintained at a constant temperature between 10°C and 16°C by a continuous supply of fresh humidified air, and tumblers are moved through the grain bed to keep it loose to allow adequate air flow. Germination typically takes 4-6 days and produces what is known as "green malt".

[0011] Kiln drying 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 enzyme denaturation. As the grain dries, the air temperature can be raised (the second stage or forced drying stage) to further dry the grain without inactivating the amylases. The target malt moisture after kiln drying is about 4% to 5% by weight. During the last few hours of kiln drying, the air temperature is raised to above 80°C (curing stage) to break down S-methylmethionine into dimethyl sulfide, thereby reducing the potential of the malt to produce dimethyl sulfide. Dimethyl sulfide is an off-flavor that tastes like cooked vegetables and / or cabbage in the final beer.

[0012] During kiln drying, the green malt layer remains undisturbed. As a result, a gradient of moisture content is formed within the layer, i.e., the lowest moisture content is observed at the bottom of the layer and a higher moisture content is observed at the top of the layer when hot air enters the layer. Typically, the green malt layer subjected to kiln drying has a thickness of 60-200 cm. As a result, the malted grains at the bottom of the layer are subjected to significantly more heat exposure than the malted grains at the top of the layer, resulting in large differences in amylase activity, etc. between these malted grains.

[0013] Derooting is the term used for the removal of small roots from the malt. Derooting is usually done soon after transfer from the kiln.

[0014] "Short malt" is a special type of malt, which differs from normal malt in that short malt is obtained by a process with a shortened germination period, typically 1-2 days. The alpha-amylase activity of short malt is considerably lower than that of normal malt.

[0015] US 4,004,034 describes a process for making wort, which comprises subjecting barley to at least one treatment cycle comprising soaking in water and then exposure to air, the temperature conditions and duration of the various stages of the cycle being selected to cause germination of the barley to form short malt and promote the development of maximum enzymatic potential, rolling the short malt, drying the rolled short malt to stop the development of biological processes occurring therein while maintaining its enzymatic potential, grinding the dried and rolled short malt and extracting it with a mixture of hot water and malt, the amount of malt being from 10% to 40% by weight of solids based on the dry weight of the mixture of ground malt and malt, and separating the wort thus produced.

[0016] US2,998,351 describes a process for malting grains which comprises continuously forming and moving a bed of grains in a predetermined path, subjecting the moving grains to a period of water spraying until they reach a moisture content of about 32% to 35% (on a wet basis), stopping the spraying of the moving bed and allowing it to stand for a period of time sufficient to allow the grains to germinate and the seed coats to rupture, then subjecting the moving bed to the following multiple stages: (a) spraying with water and (b) adjusting aeration so as to obtain a moisture content (on a wet basis) in the range of 40% to 50%, the treatment stages being carried out at temperatures between 50°F and 100°F, and finally subjecting the moving bed to a period of drying at a higher temperature.

[0017] WO 99 / 45092 describes a process for the continuous malting of cereal grains, in which the grains supplied by a feed device flow downwards through a conveyor channel under the action of gravity in alternating directions of movement and are exposed to aeration, cooling, moistening and drying media before being discharged as malt, characterized in that in a transfer region between two conveyor channels the downwardly flowing grains are divided at least into at least one upper sub-stream and one lower sub-stream, and that the sub-streams are subsequently combined again.

[0018] WO 99 / 45093 describes a method for continuous malting, wherein grain (preferably from a day cell) passes continuously in any order through the following stages: weighing, sieving, rubbing, separation of light materials, sorting, washing, scouring and wet and dry soaking, after which the soaked grain is transferred to a production unit for continuous malting.

[0019] WO 2018 / 193168 describes a continuous kernel germination process using a germination or drying tunnel, wherein:

[0020] the malt moves through an upper passage of a tunnel comprising a superimposed lower passage and an upper passage, through which the malt is conveyed by entrainment chains, the malt and the entrainment chains resting on a grid with elongated openings separating the lower passage from the upper passage,

[0021] The chain returns through the lower channel,

[0022] Air is introduced through the lower channel, passes through the grille and enters the upper channel,

[0023] The by-products fall through the openings of the grid and are entrained on the return of the chain in the opposite direction to the malt entrainment,

[0024] • And the air supply is cut off by a movable panel installed in the bottom channel above the chain return. Summary of the invention

[0025] The inventors have developed a novel process for the continuous production of dry malted grains which requires significantly less energy, time and water than conventional production methods.

[0026] The continuous method for producing dry malt grains according to the invention comprises:

[0027] a) providing a continuous flow of soaked cereals having a water content of at least 30 wt.%;

[0028] b) conveying the stream of steeped grains through a germination stage to produce a continuous stream of malted grains, the germination stage comprising: (i) maintaining the temperature of the grains in the range of 10° C.-30° C., and (ii) maintaining the moisture content of the grains in the range of 20 wt.%-38 wt.%, the residence time of the grains in the germination stage being in the range of 12 to 36 hours;

[0029] c) conveying the layers of malted grains with a second mobile conveyor through a drying stage to produce a continuous flow of dry malted grains, the drying stage comprising contacting the grains with a hot air flow reaching a maximum temperature of at least 50° C. during the drying stage, the residence time of the grains in the drying stage being in the range of 2 to 24 hours.

[0030] The method of the invention is characterized by low water uptake by the steeped grains and a short germination phase. Also because the water content of the grains is maintained at a low level of 20 wt.% to 38 wt.% during the germination phase, the energy and time required for drying the malted grains are greatly reduced.

[0031] The method of the invention offers the advantage that both germination and drying can be achieved using a thin grain layer. Thus, the method enables the production of dried malt that is very uniform in appearance (color, sprout length), water activity and enzyme activity.

[0032] The continuous kernel malting process of the invention enables the production of short malt that is extremely uniform in terms of moisture content. Therefore, the invention also provides dry malt barley obtained or obtainable by the process of the invention, said dry malt barley having the following combination of characteristics:

[0033] α-amylase activity of 1-58 dextrinizing units (DU) / g dry matter as determined by EBC method 4.13 (α-amylase content of malt);

[0034] Moisture content of 6.0 wt.% - 8.0 wt.%, as determined by EBC method 4.2 (moisture content of malt);

[0035] wherein at least 95% of the grains in the dry malted barley have a moisture content which differs by no more than 1.0 wt.% from the moisture content of the dry malted grains.

[0036] The dried malt grains of the present invention may be suitably used in the production of malt beverages such as beer and whiskey. DETAILED DESCRIPTION

[0037] A first aspect of the present invention relates to a continuous method for producing dry malt cereals, the method comprising:

[0038] a) providing a continuous flow of soaked cereals having a water content of at least 30 wt.%;

[0039] b) conveying the stream of steeped grains through a germination stage to produce a continuous stream of malted grains, the germination stage comprising: (i) maintaining the temperature of the grains in the range of 10° C.-30° C., and (ii) maintaining the moisture content of the grains in the range of 20 wt.%-38 wt.%, the residence time of the grains in the germination stage being in the range of 12 to 36 hours, wherein the stream of steeped grains is preferably conveyed through the germination stage (i) as a steeped grain layer on a first moving conveyor, or (ii) as a steeped grain stream downwardly through a germination tower under the action of gravity;

[0040] c) conveying the layers of malted grains with a second mobile conveyor through a drying stage to produce a continuous flow of dry malted grains, the drying stage comprising contacting the grains with a hot air flow reaching a maximum temperature of at least 50° C. during the drying stage, the residence time of the grains in the drying stage being in the range of 2 to 24 hours.

[0041] As used herein, the term "cereal" refers to cereal grains harvested for human consumption. Examples of cereals include barley, oats, rice, rye, wheat, corn, and sorghum.

[0042] As used herein, the term "steeping" refers to a procedure in which the grains are covered with soaking water to increase their moisture content ("wet rest"). The wet rest may be interrupted by a so-called "dry rest", during which the water is drained off and fresh air may be supplied to remove excess carbon dioxide.

[0043] As used herein, the term "germination" refers to the process of allowing a soaked grain bed to germinate under moist conditions.

[0044] As used herein, the term "sprout" refers to the initial growth stage of the malt rootlet.

[0045] As used herein, the term "malt" refers to grains that have been germinated to the point where sprouts have formed.

[0046] As used herein, the term "malt" refers to malted grains that have been dried.

[0047] As used herein, the term "short malt" refers to malt obtained by germinating barley over a period of time ranging from 12 hours to 36 hours. During this germination step, alpha-amylase is activated.

[0048] As used herein, the term "husk" refers to the outer layer of the barley grain surrounding the pericarp layer.

[0049] As used herein, the term "hulling" refers to the application of abrasion and / or friction to remove husks from non-malted grains. For example, hulling can be accomplished by using a polisher / huller / husker in which the grain is passed between a rotating drum arrangement, or by using pearling equipment that typically employs a grinding stone to strip the husks from the grain.

[0050] As used herein, the term "dehulling" refers to the application of abrasion and / or friction to remove the husk from the malted grains. For example, dehulling can be performed by using pearling equipment that typically employs grinding stones or by using a polisher / dehuller / husker (or a combination thereof) in which the husk is removed by passing the malt between rotating drums or rollers.

[0051] As used herein, the term "beer" refers to a yeast-fermented malt beverage that has optionally been hopped. Beer is typically produced by a process that includes the following basic steps:

[0052] saccharifying a mixture comprising malted cereals, preferably malted barley, optionally supplementary cereals and water to produce a mash;

[0053] Separation of mash into wort and spent grains;

[0054] · boiling the wort to produce boiled wort;

[0055] · fermenting the boiled wort with live yeast to produce fermented wort;

[0056] subjecting the fermented wort to one or more further process steps (e.g. maturation and filtration) to produce beer; and

[0057] ·Pack the beer in sealed containers such as bottles, cans or kegs.

[0058] Hops or hop extracts are typically added during the wort boil to create a hoppy beer. The hopping method and timing employed may vary depending on the beer style and brewing facility.

[0059] The method of the invention can be used to produce dry malt grain from hulled grain as well as naked grain. The grains germinated in the continuous method of the invention are preferably selected from barley grain, sorghum grain, wheat grain, rye grain and combinations thereof. Most preferably, the grain used in the method of the invention is barley grain (Hordeum vulgare).

[0060] According to a particularly preferred embodiment, the continuous flow of soaked cereals is produced by soaking dry cereals having a water content of less than 18 wt.%, more preferably 10 wt.% - 16 wt.%.

[0061] Steeping of the dry grains is preferably carried out in a continuous manner. Continuous soaking of the dry grains may suitably be carried out by conveying the grains through one or more screw conveyors (e.g., washing screws, sweeping augers) where the grains are combined with the steeping water to produce the steeped grains.

[0062] The steeping water used for steeping the cereals preferably has a temperature of 10-35°C, more preferably 15-25°C and most preferably 18-20°C.

[0063] Preferably, the total soaking time is at least 8 hours, more preferably 8-24 hours and most preferably 14-20 hours.

[0064] At the start of stage b) of the process of the invention, the soaked cereals preferably have a water content of 30-38 wt.%, more preferably 31-36 wt.% and most preferably 32-35 wt.%.

[0065] The method of the present invention can employ different types of continuous germination machines for carrying out the germination stage. According to one embodiment of the present invention, the layer of soaked grains is conveyed through the germination stage by a mobile conveyor. The soaked grains are preferably conveyed through the germination stage in a layer having an average thickness of 10-60 cm, more preferably 15-50 cm and most preferably 20-30 cm.

[0066] The mobile conveyor used in the germination phase b) is preferably selected from conveyor belts and entrainment chains. Here, the term "entrainment chain" refers to a chain of interconnected receptacles, the receptacles having an open bottom surface which is closed by a flat sliding surface on which the receptacles rest, and wherein the chains of receptacles form a closed loop and through which the receptacles can be conveyed by one or more drive pulleys.

[0067] Most preferably, the mobile conveyor used in stage b) is a conveyor belt. According to a particularly preferred embodiment, the conveyor belt has small through openings, which together cover at least 10%, more preferably 15%-70% and most preferably 20%-40% of the total surface area of ​​the conveyor belt. The through openings are preferably small enough to prevent the grain from falling. In a preferred embodiment, during the germination phase, a cool, moist air stream is blown through the through openings of the conveyor belt. Most preferably, cool, moist air is blown upwards through the openings of the conveyor belt. The cool, moist air stream preferably has a temperature in the range of 10°C-30°C, more preferably in the range of 15°C-27°C. The moist air stream preferably has a relative humidity of at least 80%, more preferably at least 90%.

[0068] According to an alternative embodiment of the method of the present invention, the continuous germination machine used to carry out the germination stage is a tower through which the soaked grains pass downwardly under gravity. The tower typically includes one or more vertically stacked chambers in which the temperature, moisture, oxygen and carbon dioxide concentrations are controlled to promote germination.

[0069] According to a particularly preferred embodiment, the cereals are agitated during at least a part of the germination phase b). Agitation can be achieved, for example, by raking, stirring, vibration, dropping (for example onto a moving belt) and / or a gas stream.

[0070] Temperature and humidity are the main factors determining the germination speed. In the method of the present invention, during the germination stage b), the temperature of the cereals is preferably maintained in the range of 15°C-35°C, more preferably in the range of 20°C-32°C, and more preferably in the range of 22°C-30°C.

[0071] During the germination stage b), the water content of the cereals is preferably maintained between 25 wt.% and 38 wt.%, more preferably between 28 wt.% and 36 wt.%, and most preferably between 30 wt.% and 35 wt.%. In order to maintain the water content within these ranges, water may be sprayed onto the soaked cereal layer during the germination stage.

[0072] During the germination phase b), the cereals are preferably exposed to an air flow in order to ensure sufficient oxygen for aerobic respiration.

[0073] The residence time of the cereals in the germination stage is preferably in the range of 12-36 hours, more preferably in the range of 18-32 hours and most preferably in the range of 20-30 hours.

[0074] The malted grains are preferably conveyed through the drying stage c) in a layer having an average thickness of 5-50 cm, more preferably 10-40 cm and most preferably 15-25 cm.

[0075] The process of the invention enables drying of malted cereals in relatively thin layers. Thus, variations in water content, color and amylase activity can be effectively minimized.

[0076] During the drying of the malted grains, the temperature of the hot air flow preferably increases during the drying process. According to a particularly preferred embodiment, the hot air flow for drying the malted grains reaches a maximum temperature of at least 55° C., more preferably a maximum temperature in the range of 60° C.-90° C. during the drying phase. The temperature of the hot air here refers to the temperature of the hot air immediately before it comes into contact with the malted grains.

[0077] The residence time of the cereals in the drying stage is preferably in the range of 2-12 hours, more preferably in the range of 2.3-10 hours and most preferably in the range of 2.5-6 hours.

[0078] The mobile conveyor used in the drying stage c) is preferably selected from a conveyor belt and an entrainment chain. More preferably, the mobile conveyor used in stage c) is a conveyor belt. According to a particularly preferred embodiment, the conveyor belt has small through openings which together cover at least 10%, more preferably 15%-70% and most preferably 20%-40% of the total surface area of ​​the conveyor belt. The through openings are preferably small enough to prevent the grain from falling. Preferably, at least a part of the hot air flow is blown through the through openings of the conveyor belt. Most preferably, the hot air is blown upwards through the openings of the conveyor belt.

[0079] During the drying stage c), the malted cereals are preferably dried to a moisture content below 18 wt.%, more preferably to a moisture content of 3-16 wt.% and most preferably to a moisture content of 5-15 wt.%.

[0080] The total residence time of the cereals in the germination and drying stages of the process of the invention is preferably in the range of 15-45 hours, more preferably in the range of 18-40 hours and most preferably in the range of 22-35 hours.

[0081] According to a further preferred embodiment, the method of the invention does not comprise an eradication step.

[0082] The dry malt cereals obtained by the process of the invention preferably have an alpha-amylase activity of 1-58 dextrinization units (DU) / gram dry matter as determined by EBC method 4.13. More preferably, the alpha-amylase activity is in the range of 1-50, more preferably in the range of 2-35, even more preferably in the range of 3-32, and most preferably in the range of 4-30 dextrinization units (DU) / gram dry matter as determined by EBC method 4.13.

[0083] The Kolbach Index of the dry malt grains obtained by the process of the present invention is preferably 5%-35%, as determined by EBC method 4.9.3. More preferably, the Kolbach Index is in the range of 8%-30%, most preferably in the range of 10%-25%.

[0084] According to a particularly preferred embodiment of the method of the invention, the cereals employed are naked cereals or husked cereals which are husked before soaking. Preferably, husking is achieved by mechanically removing the husk.

[0085] The dehulling of hulled grains has the advantage that less time is spent to achieve adequate soaking and the overall water absorption is reduced. Therefore, the energy and time required for drying are also reduced.

[0086] The hulling of the grain is preferably achieved by passing the barley through a grain hulling machine comprising one or more rotatable grinding rollers. Preferably, the hulling machine comprises two or more rotatable grinding rollers, which rotate at different speeds to apply friction to the grain passing through the gap between these rollers.

[0087] According to a particularly preferred embodiment, the grain is not completely hulled before the kernels are germinated. Complete hulling may damage the embryo of the barley grains, making the barley grains lose their ability to germinate.

[0088] During dehulling, the cereals preferably undergo a weight loss of 1%-14%, more preferably 1.5%-12%, most preferably 2%-10%.

[0089] The inventors have found that the dry malt grains obtained by the continuous kernel malting process of the present invention are relatively hard. Typically, the dry malt grains have a friability of at least 20, more preferably at least 23 and most preferably from 25 to 35, as determined by EBC method 4.15 (Friability, vitreous kernels of malt and unmodified grains determined by Friabilimeter (IM)).

[0090] Due to the low friability of the dry malt grains obtained by the method of the present invention, it is relatively easy to remove the husk without causing endosperm fragmentation. By peeling the dry malt grains, the bulk density of the malt grains can be significantly increased. Therefore, compared with ordinary malt, the space and energy required for the transportation and storage of peeled dry malt grains are significantly reduced. Therefore, in another preferred embodiment, the method of the present invention includes the step of peeling the dry malt grains to remove the husk and producing peeled malt grains.

[0091] During debarking, the dry malted cereals preferably undergo a weight loss of 1% to 14%, more preferably 2% to 12%, most preferably 2.5% to 10%.

[0092] Another aspect of the invention relates to dry malt barley obtained or obtainable by the process of the invention, said dry malt barley having the following combination of characteristics:

[0093] α-amylase activity of 1-58 dextrinizing units (DU) / g dry matter as determined by EBC method 4.13 (α-amylase content of malt);

[0094] Moisture content of 6.0 wt.% - 8.0 wt.%, as determined by EBC method 4.2 (moisture content of malt);

[0095] wherein at least 95% of the grains in the dry malted barley have a moisture content that differs by no more than 1.0 wt.% from the moisture content of the dry malted barley. Here, the wt.% difference in moisture content refers to the absolute difference in moisture content. In other words, the difference in moisture content between grains having a moisture content of 6.8 wt.% and malted barley grains having a moisture content of 7.0 wt.% is 0.2 wt.%.

[0096] In order to determine the percentage of grains having a moisture content within a specified range, 100 kernels are randomly collected from a batch of dry malted barley. The weight of each kernel is accurately determined before and after rigorous dehydration. The moisture content of each kernel is determined based on the amount of water lost during dehydration. Strict dehydration is achieved by drying the whole malted grains at a temperature of 80°C under reduced pressure. The drying time used to achieve rigorous dehydration is predetermined by drying a sample containing at least 100 kernels of dry malted barley under the above-mentioned drying conditions until the sample weight no longer decreases.

[0097] Preferably, dry malt cereals are obtained by the continuous process of the present invention.

[0098] According to a particularly preferred embodiment, the moisture content of the dry malt cereals is in the range of 6.2 wt.% - 7.8 wt.%, most preferably in the range of 6.5 wt.% - 7.5 wt.%, as determined by EBC method 4.1.

[0099] The alpha-amylase content of the dry malted cereals is preferably in the range of 2-40, most preferably 4-32 dextrinizing units (DU) per gram dry matter as determined by EBC method 4.13.

[0100] The dry malt cereals preferably have an alpha-amylase activity of 1-50 dextrinization units (DU) / gram dry matter as determined by EBC method 4.13. More preferably, the alpha-amylase activity is in the range of 2-35, even more preferably in the range of 3-32, and most preferably in the range of 4-30 dextrinization units (DU) / gram dry matter as determined by EBC method 4.13.

[0101] The Kuhlbach Index of the dry malted grains is preferably 5%-35% as determined by EBC method 4.9.3. More preferably, the Kuhlbach Index is in the range of 8%-30%, most preferably in the range of 10%-25%.

[0102] According to a particularly preferred embodiment, at least 95% of the grains in the dry malted barley have a moisture content which differs from the moisture content of the dry malted grains by no more than 0.8 wt.%, more preferably by no more than 0.6 wt.%, even more preferably by no more than 0.4 wt.% and most preferably by no more than 0.3 wt.%.

[0103] Yet another aspect of the present invention relates to a method of producing a malt beverage, the method comprising:

[0104] providing a mixture comprising malt and water, wherein at least 1 wt.% of the malt is dry malt grains according to the invention;

[0105] saccharifying the mixture to convert starch into fermentable sugars and produce a mash containing fermentable sugars; and

[0106] - The mash containing fermentable sugars is subjected to solid-liquid separation to separate the wort from the insoluble matter.

[0107] Preferably at least 10 wt.%, more preferably at least 20 wt.%, most preferably at least 40 wt.% and most preferably 100 wt.% of the malt in the mixture comprising malt and water is barley malt.

[0108] Preferably at least 3 wt.%, more preferably at least 5 wt.%, even more preferably at least 8 wt.% and most preferably at least 10 wt.% of the malt in the mixture comprising malt and water is dry malt grains according to the invention.

[0109] The mixture comprises malt and water, preferably without adjuvants.

[0110] The separation of the mash into wort and insoluble matter can suitably be carried out in a lauter tun, a mash tank, a centrifuge or a mash filter.

[0111] In a particularly preferred embodiment, the solid-liquid separation of the mash comprises filtering the mash through a filter bed, the mash comprising at least 80 wt.%, more preferably at least 90 wt.% and most preferably 100 wt.% of insoluble material from malt. Examples of apparatus that can be used for such filtering include lauter tuns and mashing tanks.

[0112] In a preferred embodiment, the process of the invention produces a wort based on 100% malt.

[0113] According to a particularly preferred embodiment, the wort is further processed to produce a malt beverage in the form of beer or whiskey, said further processing comprising the step of subjecting the wort to a yeast fermentation.Preferably the fermentation is a bottom fermentation.

[0114] The present invention is further illustrated by the following non-limiting examples.

[0115] Examples

[0116] Example 1

[0117] 7 kg of barley (two-row spring barley, originating from France) was soaked at 10° C. for 6 hours to produce soaked barley having a water content of 35 wt.%.

[0118] Next, the steeped barley was allowed to germinate for 18 hours in a layer having a thickness of about 25 cm to produce malted barley having a moisture content of 35 wt. %.

[0119] The malt grains were dried on a belt dryer for 4.5 hours to a moisture content of 7.7 wt.%. The drying conditions were as follows:

[0120] Layer thickness: 20cm

[0121] Air speed: 0.6m / s

[0122] Temperature program:

[0123] o 30 minutes at 45°C;

[0124] o 45 minutes at 62°C;

[0125] o 75 minutes heating at a constant heating rate to 80°C;

[0126] o 120 minutes at 80°C;

[0127] The dried malt thus obtained was analyzed. The results of the analysis are summarized in Table 1.

[0128] Table 1

[0129] Alpha-amylase based on dry matter (UD / g) 15 β-Amylase based on dry matter (units / g) 8.9 β-Glucanase based on dry matter (U / kg) 4.1 Wort Color (EBC) 2.5 Extracts as adjuvants based on dry matter (% (m / m)) 83.9 Restriction dextrinase activity based on dry matter (U / kg) 9.1 Lipoxygenase activity based on dry matter (UA / min / g MS) 51.4 Kurbach Index (in %) 21 Soluble protein on a dry matter basis 2.0 Total polyphenols (mg / l) 58 Protein based on dry matter (%) 9.8 Total DMS based on dry matter (mg / kg) 0.80

[0130] Example 2

[0131] According to the present invention, a continuous process is used to produce short malt from barley grain.

[0132] As shown below, barley grains are continuously soaked with soaking water at a temperature of 22°C. The barley is washed and soaked in a first washing screw, after which the soaked barley is subjected to a dry soaking stage in a first resting tank, which is continuously filled and emptied in a first-in-first-out (FIFO) manner to ensure uniform processing. The dry soaked barley obtained from the first resting tank is then soaked in a second washing screw and subjected to a combination of dry placement and wet soaking in a second resting tank, which is also operated in a FIFO manner. Both resting tanks are equipped with a spray device and a bottom outlet for water recirculation or drainage. The total residence time in the first combination of a washing screw and a resting tank is 8 hours. The total residence time in the second combination of a washing screw and a resting tank is 4-8 hours. At the end of the soaking stage, the water content of the soaked grains is about 35wt.%.

[0133] The soaked grains are continuously transferred to the germination stage by unloading them onto a first conveyor belt mounted in a closed housing, which also contains two further identical conveyor belts. The three conveyor belts are arranged one above the other so that at the end of the mobile conveyor belt the grains fall onto the mobile conveyor belt below. During the germination stage, the grains remain distributed on the conveyor belts to form a layer with an average thickness of about 50 cm. Each conveyor belt has small through openings covering 33% of the belt. During the germination stage, a continuous upward flow of humidified air is maintained. The humidified air has a temperature of about 20° C. The moisture content of the grains is maintained at about 35 wt.% by spraying the grain layer with water at fixed time intervals. The total residence time of the grains on the conveyor belts is about 24 hours. At the end of the germination stage, the moisture content of the malted grains is about 35 wt.%. The percentage of germinated grains exceeds 85%

[0134] After germination, the malted grains are continuously transferred to the drying stage, which consists of three consecutive phases:

[0135] Withering stage;

[0136] Breakpoint drying stage

[0137] Curing and drying stage

[0138] Each of the three consecutive drying phases is carried out in a belt dryer comprising a conveyor belt having small through openings covering 33% of the belt.

[0139] The drying conditions during each stage are summarized below.

[0140] Withering period:

[0141] Product layer thickness: 10–15 cm

[0142] Dry air temperature: 45℃-55℃

[0143] ·Dwelling time: 30-60 minutes

[0144] Moisture content at the end of the wilting period: 28%-30%

[0145] Breakpoint drying period;

[0146] Product layer thickness: 14–28cm

[0147] Dry air temperature: 60℃-70℃

[0148] Duration: 45-90 minutes

[0149] Moisture content at the end of the break-point drying period: 17%-20%

[0150] Curing and drying period;

[0151] Product layer thickness: 22-36cm

[0152] Dry air temperature: 70℃-80℃

[0153] Duration: 75-120 minutes

[0154] Moisture content at the end of the curing drying period: <10%

[0155] Example 3

[0156] Barley (two-row spring barley, origin France) was dehulled in a Satake Test Mill (TM05C(2)-T) in batches of 100 g. The total amount of material removed during dehulling was 6.7 wt.%.

[0157] The dehulled barley thus obtained was converted into dry malted barley using a continuous kernel malting process as described in Example 2. The total amount of water absorbed during steeping and the total amount of water that needed to be removed during drying (calculated on the weight of the unhulled barley) was significantly lower than in the process of Example 2.

[0158] Example 4

[0159] The short malt obtained by the process described in Example 2 was dehulled in batches of 100 grams in a Satake test mill (TM05C(2)-T). The total amount of material removed by dehulling was about 14 wt.%. Due to dehulling, the extract content of the malt (EBC 6.4) increased significantly.

Claims

1. A continuous process for producing dry malt cereals, the process comprising: a) providing a continuous flow of soaked cereals having a water content of at least 30 wt.%; b) conveying the stream of steeped grains through a germination stage to produce a continuous stream of malted grains, the germination stage comprising: (i) maintaining the temperature of the grains in the range of 10° C.-30° C., and (ii) maintaining the moisture content of the grains in the range of 20 wt.%-38 wt.%, the residence time of the grains in the germination stage being in the range of 12 to 36 hours, wherein the stream of steeped grains is preferably conveyed through the germination stage (i) as a steeped grain layer on a first moving conveyor, or (ii) as a steeped grain stream downwardly through a germination tower under the action of gravity; c) conveying the layers of malted grains with a second mobile conveyor through a drying stage to produce a continuous flow of dry malted grains, the drying stage comprising contacting the grains with a hot air flow reaching a maximum temperature of at least 50° C. during the drying stage, the residence time of the grains in the drying stage being in the range of 2 to 24 hours.

2. The continuous process according to claim 1, wherein the grains are selected from the group consisting of barley grain, sorghum grain, wheat grain, rye grain and combinations thereof.

3. A continuous process according to claim 1 or 2, wherein the continuous flow of soaked grains is produced by conveying dry grains having a water content of less than 18 wt.% through a screw conveyor, wherein the grains are combined with water to produce the soaked grains.

4. The continuous process according to any one of the preceding claims, wherein the soaked cereals have a water content of 25 to 38 wt.%.

5. The continuous process according to any one of the preceding claims, wherein the soaked grains are conveyed through the germination stage in a layer having an average thickness of 10-30 cm.

6. A continuous process according to any one of the preceding claims, wherein the layer of cereals is agitated during at least part of said stage b).

7. The continuous process according to any one of the preceding claims, wherein during stage b) the water content of the cereals is maintained between 28 wt.% and 36 wt.%.

8. The continuous process according to any one of the preceding claims, wherein the mobile conveyor used in stage b) and / or stage c) is selected from conveyor belts and entrainer chains.

9. A continuous process according to claim 8, wherein the mobile conveyor used in stage c) is a conveyor belt with small through openings, which together cover at least 10% of the total surface area of ​​the conveyor belt, and at least a part of the hot air flow is blown through these small openings.

10. The continuous process according to any one of the preceding claims, wherein the malt grains are conveyed through the drying stage in a layer having an average thickness of 5-50 cm.

11. The continuous process according to any one of the preceding claims, wherein the malt grains are dried to a moisture content of less than 18 wt.%.

12. The continuous process according to any one of the preceding claims, wherein the dry malt grains obtained by the process have an alpha-amylase activity of 1-58 dextrinizing units (DU) / gram dry matter as determined by EBC method 4.

13.

13. A dry malted barley obtained by the method according to any one of the preceding claims, said dry malted barley having the following combination of characteristics: α-amylase activity of 1-58 dextrinizing units (DU) / g dry matter as determined by EBC method 4.13 (α-amylase content of malt); Moisture content of 6.0 wt.% - 8.0 wt.%, as determined by EBC method 4.2 (moisture content of malt); wherein at least 95% of the grains in the dry malted barley have a moisture content which differs by no more than 1.0 wt.% from the moisture content of the dry malted grains.

14. The dry malted barley according to claim 13, wherein the dry malted barley has a Kuhlbach Index of 5%-35% as determined by EBC method 4.9.

3.

15. A method of producing a malt beverage, the method comprising: providing a mixture comprising malt and water, wherein at least 1 wt.% of the malt is dry malt grains according to claim 13 or 14; saccharifying the mixture to convert starch into fermentable sugars and produce a mash containing the fermentable sugars; and - The mash containing fermentable sugars is subjected to solid-liquid separation to separate the wort from the insoluble matter.