An amber roasty malt with bread aroma, a method for preparing the same and a beer

Abstract

The application discloses amber caramel malt with bread aroma, a preparation method thereof and beer, and belongs to the field of malt manufacturing. The amber caramel malt with bread aroma comprises a germination step, and the germination step comprises: a first germination stage of 0-12 hours, a second germination stage of 12-72 hours, and a third germination stage of 72-96 hours; the germination temperature of the third germination stage is higher than that of the second germination stage, and the germination temperature of the second germination stage is higher than that of the first germination stage. The application is applied to the field of special malt manufacturing, solves the problem that special malts such as caramel malt, amber malt and biscuit malt inevitably produce obvious caramel taste, paste taste and other bad flavors due to the limitation of the preparation process, affect the purity of bread aroma, and cause the problem of mixed aroma, and the amber caramel malt prepared by the application has typical bread aroma, clean and coordinated wine body, and no caramel taste, paste taste and other miscellaneous flavors.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of malt manufacturing, and particularly relates to amber roasty malt with bread aroma, a preparation method thereof, and beer. BACKGROUND

[0002] The Chinese beer market is the largest beer consumption market in the world, and the mid-to-high-end market is increasing under the trend of consumption upgrading. Domestic beer cannot meet the high-end and diversified consumer demand, resulting in rapid occupation of the mid-to-high-end market by imported beer.

[0003] Special malt gives beer characteristic aroma and taste, which is the key to differentiated product innovation. Among them, bread aroma is a typical flavor characteristic of special malt, and the strength of malt bread aroma has a guiding effect on the bread flavor of beer. 2-acetylpyrrole (2-AP) is the main flavor substance of malt bread aroma, and its content depends on the efficiency of malt carbonyl-ammonia reaction, which is closely related to the Maillard reaction.

[0004] However, in the prior art, although special malts such as roasty malt, amber malt, biscuit malt have bread aroma, due to the limitations of the preparation process, they only rely on high-temperature Maillard reaction to increase the content of 2-AP, which inevitably produces obvious burnt taste, paste taste and other undesirable flavors, affecting the purity of bread aroma and leading to mixed aroma.

[0005] Therefore, there is an urgent need in the art for a preparation method of roasty malt with high bread aroma. When the malt prepared by the method is applied to beer brewing, the sensory evaluation has typical bread aroma, the wine body is clean and coordinated, and there is no burnt taste, paste taste and other miscellaneous flavors. SUMMARY

[0006] In view of the deficiencies in the prior art, the technical problem to be solved by the present application is to overcome the problem that existing roasty malt, amber malt, biscuit malt and other special malts, due to the limitations of the preparation process, although they have bread aroma, they inevitably produce obvious burnt taste, paste taste and other undesirable flavors, affecting the purity of bread aroma and leading to mixed aroma. A kind of amber roasty malt with bread aroma, a preparation method thereof and beer are provided, which has typical bread aroma, clean and coordinated wine body, and no burnt taste, paste taste and other miscellaneous flavors.

[0007] To solve the technical problem, the technical scheme adopted by the present application is:

[0008] The present application provides a method for preparing amber roasted malt with bread aroma, comprising a germination step, wherein the germination step comprises a first germination stage of 0-12 hours, a second germination stage of 12-72 hours, and a third germination stage of 72-96 hours; the germination temperature of the third germination stage is higher than that of the second germination stage, and the germination temperature of the second germination stage is higher than that of the first germination stage.

[0009] Preferably, the germination temperature of the first germination stage is any value in the range of 12-13℃; the germination temperature of the second germination stage is any value in the range of 14-16℃; and the germination temperature of the third germination stage is any value in the range of 17-18℃.

[0010] Preferably, the method further comprises a protein rest step after the germination step, and the moisture content of the green malt after the protein rest step is any value in the range of 12-15%.

[0011] Preferably, the air exhaust amount in the protein rest step is not less than 4.5m 3 / min.

[0012] Preferably, the rest temperature in the protein rest step is 50℃, and the rest time is 40 minutes.

[0013] Preferably, the method further comprises a baking step after the protein rest step, wherein the baking temperature in the baking step is any value in the range of 95-100℃, and the baking time is any value in the range of 120-140 minutes.

[0014] Preferably, the method further comprises a selection step before the germination step, wherein the selection step comprises selecting Copeland and / or Synergy and / or Metcalfe as the raw material for malting.

[0015] The present application provides an amber roasted malt with bread aroma, which is prepared by the method for preparing amber roasted malt with bread aroma according to any one of the technical solutions described above.

[0016] The present application further provides a beer, which is brewed by the amber roasted malt with bread aroma according to the technical solutions described above.

[0017] Compared with the prior art, the present application has the following beneficial effects:

[0018] The present application provides a preparation method of amber roasted malt with bread aroma, which adopts a gradient temperature rising germination process, and further promotes the generation of hydrolytic enzyme through low temperature germination in the early stage of germination, and gradually increases the germination temperature in the middle and later stages of germination, so as to effectively promote the decomposition of protein, increase the total amount of serine (high serine content is beneficial to the generation of 2-AP), and obtain amber roasted malt with high bread aroma. DETAILED DESCRIPTION

[0019] The technical solutions in the specific embodiments of the present application will be described in detail below. Obviously, the described embodiments are only part of the specific implementations of the general technical solutions of the present application, but not all the implementations. Based on the general concept of the present application, all other embodiments obtained by those skilled in the art fall within the scope of protection of the present application.

[0020] The present application provides a preparation method of amber roasted malt with bread aroma, which adopts a gradient temperature rising germination process, and further promotes the generation of hydrolytic enzyme through low temperature germination in the early stage of germination, and gradually increases the germination temperature in the middle and later stages of germination, so as to effectively promote the decomposition of protein, increase the total amount of serine (high serine content is beneficial to the generation of 2-AP), and obtain amber roasted malt with high bread aroma.

[0021] In a preferred embodiment, the germination temperature of the first germination stage is any value in the range of 12-13℃; the germination temperature of the second germination stage is any value in the range of 14-16℃; and the germination temperature of the third germination stage is any value in the range of 17-18℃. The present technical solution further limits the germination temperature of the first germination stage, the germination temperature of the second germination stage, and the germination temperature of the third germination stage, because the amino acid composition of different varieties of barley is not significantly different at the same germination temperature, while the amino acid content and composition of the same variety of barley prepared using different germination temperatures are significantly different. The use of gradient heating process here is to increase the content of serine, and thus improve the bread aroma.

[0022] In a preferred embodiment, a protein rest step is further included after the germination step, and the moisture content of the green malt after the protein rest step is any value in the range of 12-15%. It can be understood that the moisture content of the green malt can also be 13%, 14%, and any point value within the range thereof.

[0023] In a preferred embodiment, the air exhaust amount in the protein rest step is not less than 4.5m 3 / min. The present technical solution limits the air exhaust amount in the protein rest step, which reduces the moisture content of the green malt entering the oven by increasing the air exhaust amount.

[0024] In a preferred embodiment, the rest temperature of the protein rest step is 50℃, and the rest time is 40min. The present embodiment specifically limits the rest temperature and rest time of the protein rest step, which is beneficial to the decomposition of polypeptides by carboxypeptidases to form amino acids and the decomposition of proteins by endopeptidases to form polypeptides and amino acids, and thus promotes the generation of serine.

[0025] In a preferred embodiment, a baking step is further included after the protein rest step, and the baking temperature of the baking step is any value in the range of 95-100℃, and the baking time is any value in the range of 120-140min. By limiting the moisture content of the green malt entering the oven, the baking temperature, and the baking time in the baking process, the generation of 2-AP is effectively ensured, and the bread aroma of the malt is ensured. It can be understood that the baking temperature can also be 96℃, 97℃, 98℃, 99℃, and any point value within the range thereof, and the baking time can also be 125min, 130min, 135min, and any point value within the range thereof.

[0026] In a preferred embodiment, a malting selection step before the germination step is further included, and the malting selection step comprises selecting malting Copeland and / or malting Synergy / or malting Metcalfe as the malting raw material. The technical solution specifically limits the selected malt type, and the reason is that the malt bread aroma is mainly derived from the Maillard reaction between carbonyl and amino groups, and the content of sugar substances in the malt is much higher than that of nitrogen-containing substances, so it is necessary to select a barley variety with high protein content from the source to promote the generation of aroma substances.

[0027] Another aspect of the present application provides a bread-aroma amber-roasted malt prepared by the method for preparing the bread-aroma amber-roasted malt according to any one of the above technical solutions. The bread-aroma amber-roasted malt has a typical bread aroma and no burnt taste, paste taste or other miscellaneous flavors.

[0028] The present application also provides a beer brewed from the bread-aroma amber-roasted malt according to the above technical solution. The beer has a typical bread aroma and a clean and coordinated body.

[0029] In order to more clearly and specifically introduce the bread-aroma amber-roasted malt, the method for preparing the bread-aroma amber-roasted malt and the beer provided by the embodiments of the present application, the following will be described in combination with specific embodiments.

[0030] Embodiment 1

[0031] 1. Bread-aroma amber-roasted malt - malting Copeland

[0032] (1) Malting selection: malting Copeland with a protein content of 12.3% is selected as the raw material, the barley grains are full, and the barley germination rate is 99%;

[0033] (2) Raw material pretreatment: the barley is cleaned to remove straw, bag rope, wood blocks, nails, screws, metal wires, stones, impurities, and broken barley grains; and is classified by screening to retain uniform-sized barley with a length of 2.5mm-2.8mm;

[0034] (3) Malting: malting water is added to the malting tank, and then the barley is discharged into the malting tank. A small amount of floating barley and impurities floating on the liquid surface are collected through the collection port to complete the floating barley operation. After the floating barley operation is completed, the water quality is changed, and the malting is performed by using a low-temperature long-time soaking and discontinuing method with three soaking and two discontinuing at a water temperature of 15℃, which includes a first wet soaking stage (wet soaking for 5h), a first dry soaking stage (dry soaking for 15h), a second wet soaking stage (wet soaking for 7h), a second dry soaking stage (dry soaking for 11h), and a third wet soaking stage (wet soaking for 2h). The final malting degree reaches 45%, and continuous ventilation oxygen supply is adopted during the malting process;

[0035] (4) Germination: The germination process is carried out in a ventilated germination device, and the germination temperature is controlled at 12-18°C, and the germination time is 96h in total. The first 0-12h of germination is the first stage of germination, and the germination temperature is 12°C; the next 12-72h is the second stage of germination, and the germination temperature is 14°C; and the last 72-96h is the third stage of germination, and the germination temperature is 17°C. The first stirring time of germination is 12-20h after the end of discharging, and the malt is turned over every 10-12h during the early and wilting stages of germination, and every 6-9h during the vigorous stage of germination. The average length of the leaf bud at the end of germination is 4 / 5-5 / 5 of the length of the grain, the proportion of malt in the total malt is 95%, and the germination rate reaches 99%;

[0036] (5) Green malt protein rest: The green malt is placed in a baking oven, and the baking oven is uniformly heated at a speed of 1.5-2.0°C / min, and after the temperature is raised to 50°C, the temperature is kept constant for 40min to rest the protein. At the same time, the exhaust volume of the baking oven is controlled at 4.5m 3 / min, and the moisture content of the green malt is 15% at the end of protein rest. This process takes low temperature and large exhaust volume to remove the moisture of the green malt, promotes the wilting of the green malt, reduces the damage of enzymes, and further promotes the generation of amino acids. If the exhaust volume is low, the dehydration speed will be slow, and the malt is easy to produce green taste, which affects the purity of the aroma.

[0037] (6) Baking: After the protein rest, the rotating speed of the baking oven is increased to 8r / min, and the temperature is quickly raised to 95°C, and the baking is carried out for 140min.

[0038] (7) Root removal: The malt obtained by step (6) is immediately removed from the root to obtain a kind of amber caramel malt with bread aroma.

[0039] The physicochemical indexes of the malt prepared by the above steps, the content of 2-AP in the malt extract, and the sensory evaluation results are shown in Tables 1, 2 and 3.

[0040] Table 1 Physicochemical indexes of malt

[0041]

[0042] Table 2 Content of 2-AP in malt extract

[0043] Component Unit Common malt Malt prepared in Example 1 Purchased caramel malt 2-AP ug / L ND Component Unit 629 122

[0044] Table 3 Sensory evaluation results of malt extract

[0045]

[0046] 2. Beer with high bread aroma

[0047] The brewing raw material used 70% of Pilsen malt and added 30% of malted Copeland prepared in Example 1 to brew the product wine, the physicochemical indexes of which met the standard of GB / T 4927-2008, and the sensory evaluation results of the product wine by the national-level wine taster were shown in Table 4.

[0048] Table 4 Sensory evaluation results of the product wine

[0049]

[0050] Example 2

[0051] 1. Bread aroma amber caramel malt-malted Synergy

[0052] (1) Selection of malt: select malted Synergy with a protein content of 12.6% as raw material, the barley grains are full, and the barley germination rate is 99%;

[0053] (2) Pretreatment of raw materials: clean the barley to remove straw, bag rope, wood, nails, screws, metal wire, stone, impurities, and broken grains, etc.; and screen and grade the barley, and keep the size uniform barley with a length of 2.5-2.8 mm;

[0054] (3) Malting: add the malting water into the malting tank, then discharge the barley into the malting tank, and collect the floating barley and impurities on the liquid surface through the collection port to complete the floating barley operation; after the floating barley operation is completed, the water quality is changed, and the malting is performed by using the low-temperature long-time soaking and discontinuing method of three soaking and two discontinuing at a water temperature of 15℃, which includes a first wet soaking stage (wet soaking for 5 h), a first dry soaking stage (dry soaking for 15 h), a second wet soaking stage (wet soaking for 7 h), a second dry soaking stage (dry soaking for 11 h), and a third wet soaking stage (wet soaking for 2 h) in sequence, and the final malting degree reaches 45%, and continuous ventilation oxygen supply is used in the malting process;

[0055] (4) Germination: the germination process is performed in a ventilation type germination equipment, the germination temperature is controlled at 12-18℃, and the germination time is 96 h. The germination temperature is 13℃ for the first stage of germination for 0-12 h, the germination temperature is 16℃ for the second stage of germination for 12-72 h, and the germination temperature is 18℃ for the third stage of germination for 72-96 h. The first stirring time of germination is 12-20 hours after the discharge is completed, the barley is turned over once every 10-12 hours in the early and wilting stages of germination, and the barley is turned over once every 6-9 hours in the vigorous growth stage of germination. The average leaf bud length is 4 / 5-5 / 5 of the grain length after the germination is completed, the proportion of the malted barley is 95%, and the germination rate reaches 99%;

[0056] (5) Green malt protein rest: the green malt is placed in the baking oven, the baking oven is uniformly heated at a speed of 1.5-2.0℃ / min, and after the temperature is raised to 50℃, the protein is rested for 40min at constant temperature. At the same time, the exhaust volume of the baking oven is controlled at 4.7m 3 / min, the moisture content of the green malt protein is 12% at the end of the rest. This process takes low temperature and large exhaust volume to remove the moisture of the green malt, promotes the wilting of the green malt, reduces the damage of the enzyme, and further promotes the generation of amino acids. If the exhaust volume is low, it will inevitably cause slow dehydration, which will make the malt prone to produce green taste and affect the purity of the aroma.

[0057] (6) Baking: after the protein rest is finished, the speed of the baking oven is increased to 8r / min, and the temperature is quickly raised to 100℃, and baked for 120min.

[0058] (7) Root removal: the malt obtained after step (6) is immediately removed from the root to obtain a bread aroma rich amber roasted malt.

[0059] The physicochemical indexes of the malt prepared by the above steps, the 2-AP content of the wort and the sensory evaluation results are shown in Tables 5, 6 and 7.

[0060] Table 5 Physicochemical indexes of malt

[0061]

[0062] Table 6 2-AP content of wort

[0063] Common malt Malt prepared in Example 2 Purchased caramel malt 2-AP ug / L ND Component Unit Common malt 605 122

[0064] Table 7 Sensory evaluation results of wort

[0065]

[0066] 2, Beer with high bread aroma

[0067] 70% of Pilsen malt is used in the brewing raw materials, and 30% of the malt Synergy prepared in Example 2 is added, and the finished product is brewed to meet the GB / T 4927-2008 standard. The sensory evaluation results of the national level product wine taster are shown in Table 8.

[0068] Table 8 Sensory evaluation results of finished product wine

[0069]

[0070] Example 3

[0071] 1, Bread aroma amber roasted malt-malt Metcalfe

[0072] (1) Selecting raw material: Metcalfe barley with 11.7% protein content was selected as raw material, and the barley kernel was full, and the germination rate of the barley was 99%;

[0073] (2) Pretreatment of raw material: The barley was cleaned to remove straw, bag rope, wood block, iron nail, screw, metal wire, stone, chaff, and broken barley kernel; and was classified by screening to retain the barley with uniform size and length of 2.5-2.8 mm;

[0074] (3) Soaking: the soaking water was added to the soaking tank, and then the barley was fed into the soaking tank, and the floating barley and impurities floating on the liquid surface were collected through the collecting port to complete the floating barley operation; after the floating barley operation was completed, the water was replaced, and the barley was soaked at a water temperature of 15℃ by using the low-temperature long-time soaking and discontinuous water supply method of three soaking and two discontinuous water supply, which included a first wet soaking stage (wet soaking for 5 h), a first dry soaking stage (dry soaking for 15 h), a second wet soaking stage (wet soaking for 7 h), a second dry soaking stage (dry soaking for 11 h), and a third wet soaking stage (wet soaking for 2 h), and finally the soaking degree reached 45%, and continuous ventilation oxygen supply was adopted during the soaking process;

[0075] (4) Germination: the germination process was carried out in a ventilation type germination equipment, and the germination temperature was controlled at 12-18℃, and the germination time was 96 h. The germination temperature was 13℃ in the first stage of germination for 0-12 h, the germination temperature was 16℃ in the second stage of germination for 12-72 h, and the germination temperature was 18℃ in the third stage of germination for 72-96 h. The first stirring time of germination was 12-20 hours after the feeding was completed, the barley was turned over once every 10-12 hours in the early and wilting stages of germination, and the barley was turned over once every 6-9 hours in the vigorous growth stage of germination. The average leaf bud length was 4 / 5-5 / 5 of the kernel length after the germination was completed, the proportion of the malt kernel was 95%, and the germination rate reached 99%;

[0076] (5) Green malt protein rest: the green malt was placed in a baking oven, the baking oven was uniformly heated at a speed of 1.5-2.0℃ / min, and after the temperature was raised to 50℃, the constant temperature protein rest was carried out for 40 min, and the serine content was 216 mg / L. At the same time, the exhaust volume of the baking oven was controlled at 4.7 m 3 / min, the water content of the green malt was 14% after the protein rest of the green malt was completed, this process adopted low temperature and large exhaust volume to remove the water of the green malt, promoted the wilting of the green malt, and reduced the damage of the enzyme, and further promoted the generation of amino acids. If the exhaust volume is low, the dehydration speed will be slow, the malt is easy to produce green taste, and the purity of the aroma is affected.

[0077] (6) Baking: after the saccharification was completed, the rotating speed of the baking oven was increased to 8 r / min, the temperature was rapidly raised to 98℃, and the baking was carried out for 116 min.

[0078] (7) Rootlet removal: the malt obtained in step (6) is immediately subjected to rootlet removal, thereby obtaining a bread-aroma-rich amber-roasted malt.

[0079] The physicochemical indexes of the malt prepared by the above steps, the 2-AP content of the wort, and the sensory evaluation results are shown in Tables 9, 10, and 11.

[0080] Table 9 Physicochemical indexes of malt

[0081]

[0082] Table 10 2-AP content of wort

[0083] Malt prepared in Example 3 Purchased caramel malt 2-AP ug / L ND Name Result of sensory evaluation of wort 2-AP content ug / L 617 122

[0084] Table 11 Sensory evaluation results of wort

[0085]

[0086] 2. Beer with high bread aroma

[0087] 70% of Pilsen malt and 30% of the malt Metcalfe prepared in Example 3 are used as brewing raw materials, and the physicochemical indexes of the finished product meet the GB / T 4927-2008 standard, and the sensory evaluation results of the national-level product wine taster are shown in Table 12.

[0088] Table 12 Sensory evaluation results of finished product

[0089]

[0090] Comparative Example 1

[0091] The same as Example 1, except that the malting process uses constant-temperature malting process. Specifically:

[0092] 1. Amber-roasted malt - malt Copeland

[0093] (1) Selection of raw materials: select malt Copeland with a protein content of 12.3% as raw material, the barley is full, and the barley germination rate is 99%;

[0094] (2) Pretreatment of raw materials: the barley is cleaned to remove straw, bag rope, wood block, iron nail, screw, metal wire, stone, impurity grain, and broken grain; and is classified by screening to retain uniform-sized barley with a length of 2.5-2.8 mm;

[0095] (3) Mashing: the mashing water is added to the mashing tank, then the barley is discharged into the mashing tank, and a small amount of floating barley and impurities floating on the surface of the liquid are collected through the collecting port to complete the floating barley operation; after the floating barley operation is completed, the water quality is changed, and the low-temperature long-time mashing and water interruption method of three mashing and two interruption is used at a water temperature of 15°C, which includes a first wet mashing stage (wet mashing for 5 h), a first dry mashing stage (dry mashing for 15 h), a second wet mashing stage (wet mashing for 7 h), a second dry mashing stage (dry mashing for 11 h), and a third wet mashing stage (wet mashing for 2 h) in sequence, and the final mashing degree reaches 45%, and continuous ventilation oxygen supply is used during the mashing process;

[0096] (4) Germination: the germination process is carried out in a ventilation type germination equipment, and the temperature during the germination process is controlled at 16°C for 0-96 h. The first stirring time during the germination process is 12-20 hours after the discharging is completed, the malt is turned over once every 10-12 hours during the early and wilting stages of the germination process, and the malt is turned over once every 6-9 hours during the vigorous stage of the germination process. The average leaf bud length after the germination process is completed is 4 / 5-5 / 5 of the length of the grain, the proportion of the malt in the total malt is 95%, and the germination rate reaches 99%;

[0097] (5) Green malt protein rest: the green malt is placed in a baking oven, the baking oven is uniformly heated at a speed of 1.5-2.0°C / min, and after the temperature is raised to 50 degrees, the temperature is kept constant for 40 min for protein rest, and the serine content is 102 mg / L after the rest is completed. At the same time, the exhaust volume of the baking oven is controlled at 4.5 m 3 / min, the water content of the green malt is 15% after the protein rest of the green malt is completed, this process adopts low temperature and large exhaust volume to discharge the water of the green malt, promotes the wilting of the green malt, and reduces the damage of the enzyme, and further promotes the generation of amino acids. If the exhaust volume is low, the dehydration speed will be slow, the malt is easy to produce green taste, and the purity of the aroma is affected.

[0098] (6) Baking: after the protein rest is completed, the rotating speed of the baking oven is increased to 8 r / min, the temperature is rapidly raised to 95°C, and the baking is performed for 140 min.

[0099] (7) Root removal: the malt obtained after step (6) is immediately removed from the root to obtain amber roasted malt.

[0100] Comparative Example 2

[0101] The same as in Example 1, except that a cooling germination process is used in the germination process. Specifically:

[0102] 1. Amber roasted malt - Copeland

[0103] (1) Selection of barley: Copeland with a protein content of 12.3% is selected as the raw material, and the barley is full and the germination rate is 99%;

[0104] (2) Raw material pretreatment: The barley is cleaned to remove straw, bag rope, wood block, iron nail, screw, metal wire, stone, chaff, broken barley, etc.; and is classified by screening to retain the uniform-sized barley with a length of 2.5-2.8 mm;

[0105] (3) Malt steeping: The steeping water is added to the steeping tank, and then the barley is discharged into the steeping tank. The floating barley and impurities floating on the surface are collected through the collection port to complete the floating barley operation. After the floating barley operation is completed, the water quality is changed. The low-temperature long-time steeping and discontinuous water method is used for steeping at a water temperature of 15°C, which includes a first wet steeping stage (wet steeping for 5 h), a first dry steeping stage (dry steeping for 15 h), a second wet steeping stage (wet steeping for 7 h), a second dry steeping stage (dry steeping for 11 h), and a third wet steeping stage (wet steeping for 2 h). The final steeping degree reaches 45%, and continuous ventilation oxygen supply is used during the steeping process.

[0106] (4) Germination: The germination process is carried out in a ventilated germination equipment. The germination temperature is controlled at 12-18°C, and the germination time is 96 h. The first stage of germination is 0-12 h, and the germination temperature is 17°C. The second stage of germination is 12-72 h, and the germination temperature is 14°C. The third stage of germination is 72-96 h, and the germination temperature is 12°C. The first stirring time of germination is 12-20 hours after the discharge is completed. The barley is turned over every 10-12 hours during the early and wilting stages of germination, and every 6-9 hours during the vigorous stage of germination. The average leaf bud length after germination is 4 / 5-5 / 5 of the grain length, the proportion of malt to total barley is 95%, and the germination rate reaches 99%.

[0107] (5) Green malt protein rest: The green malt is placed in a baking oven, which is uniformly heated at a speed of 1.5-2.0°C / min. After the temperature rises to 50°C, the oven is kept at a constant temperature for 40 min for protein rest, with a serine concentration of 117 mg / L. At the same time, the exhaust volume of the baking oven is controlled at 4.5 m 3 / min. The moisture content of the green malt after protein rest is 15%. This process uses low temperature and large exhaust volume to remove the moisture of the green malt, promotes the wilting of the green malt, reduces the damage of enzymes, and further promotes the generation of amino acids. If the exhaust volume is low, the dehydration speed will be slow, which may cause the malt to produce a green taste and affect the purity of the aroma.

[0108] (6) Baking: After the protein rest, the rotation speed of the baking oven is increased to 8 r / min, and the temperature is quickly raised to 95°C. The baking time is 140 min.

[0109] (7) Root removal: The malt obtained after step (6) is immediately removed from the roots to obtain amber caramel malt.

[0110] Comparative Example 3

[0111] The difference between the embodiment 1 is that the baking process adopts high-temperature roasting process 140℃ roasting, in particular:

[0112] (1) Selecting: Select Copeland with protein content of 12.3% as raw material, the barley grain is full, and the barley germination rate is 99%;

[0113] (2) Raw material pretreatment: The barley is cleaned to remove straw, bag rope, wood block, iron nail, screw, metal wire, stone, impurity grain, and broken barley grain; and is screened and graded to keep the uniform size of the barley with length of 2.5mm-2.8mm;

[0114] (3) Soaking: The soaking water is added to the soaking tank, and then the barley is discharged to the soaking tank. A small part of the floating barley and impurities on the liquid surface are collected through the collecting port to complete the floating barley operation. After the floating barley is completed, the water quality is changed, and the low-temperature long-time soaking and discontinuous water method is used for soaking at water temperature of 15℃, which includes first wet soaking stage (wet soaking for 5h), first dry soaking stage (dry soaking for 15h), second wet soaking stage (wet soaking for 7h), second dry soaking stage (dry soaking for 11h), and third wet soaking stage (wet soaking for 2h) in sequence. The final soaking degree reaches 45%, and continuous ventilation oxygen supply is adopted during the soaking process;

[0115] (4) Germination: The germination process is carried out in a ventilation type germination equipment, and the germination temperature is controlled at 12-18℃. The germination time is 96h in total. The germination temperature is 12℃ in the first germination stage for 0-12h, the germination temperature is 14℃ in the second germination stage for 12-72h, and the germination temperature is 17℃ in the third germination stage for 72-96h. The first stirring time of germination is 12-20 hours after the discharge is completed. The barley is turned over once every 10-12 hours in the early and wilting stages of germination, and once every 6-9 hours in the vigorous stage of germination. The average leaf bud length is 4 / 5-5 / 5 of the grain length after the germination is completed, the proportion of the barley malt is 95%, and the germination rate reaches 99%;

[0116] (5) Green malt protein rest: The green malt is placed in the baking oven, the baking oven is uniformly heated at a speed of 1.5-2.0℃ / min, and the temperature is raised to 50 degrees. The temperature is kept constant for 40 minutes, the serine content is 230mg / L. At the same time, the exhaust volume of the baking oven is controlled at 4.5m 3 / min, the moisture content of the green malt protein rest is 15%, this process adopts low temperature, large exhaust volume to remove the moisture of the green malt, promotes the wilting of the green malt, and reduces the damage of the enzyme, further promotes the generation of amino acids. If the exhaust volume is low, it will inevitably cause slow dehydration, which makes the malt easy to produce green taste, affecting the purity of the aroma.

[0117] (6) Baking: After the end of the protein rest, the baking oven speed is increased to 8 r / min, and the temperature is rapidly increased to 140°C, and baking is performed for 140 min.

[0118] (7) Rooting: The malt obtained in step (6) is immediately rooted to obtain amber roasted malt.

[0119] Performance test

[0120] The worts obtained in Examples 1-3 and Comparative Examples 1-3 are subjected to sensory evaluation and content detection, and the results are shown in Table 13.

[0121] Table 13 Performance results of worts obtained in Examples 1-3 and Comparative Examples 1-3

[0122] Example 1 Has a clean, rich bread aroma, and a sweet, clean taste Example 2 Has a clean, rich bread aroma, and a sweet, clean taste Example 3 629 Has a clean, rich bread aroma, and a sweet, clean taste Comparative Example 1 605 Has a weak bread aroma, a sweet taste, and a clean taste Comparative Example 2 617 Has a weak bread aroma, a sweet taste, and a clean taste Comparative Example 3 189 Has a weak bread aroma and a weak caramel aroma, a sweet taste, and a clean taste ​ 142 ​ ​ 118

Claims

1. A method for producing a bread-aroma-possessing amber-roasted malt comprising a malting step, characterized by, the germination step comprises a first germination stage of 0-12 h, a second germination stage of 12-72 h, and a third germination stage of 72-96 h; the germination temperature of the third germination stage is higher than that of the second germination stage, and the germination temperature of the second germination stage is higher than that of the first germination stage; the germination temperature of the first germination stage is any value in the range of 12-13℃; the germination temperature of the second germination stage is any value in the range of 14-16℃; the germination temperature of the third germination stage is any value in the range of 17-18℃; the method further comprises a protein rest step after the germination step, and the moisture content of the green malt after the protein rest step is any value in the range of 12-15%; the rest temperature of the protein rest step is 50℃, and the rest time is 40 min; the method further comprises a baking step after the protein rest step, and the baking temperature of the baking step is any value in the range of 95-100℃, and the baking time is any value in the range of 120-140 min.

2. The method for producing the bread-aroma-possessing amber roasty malt according to Claim 1, characterized by, The protein rest step is controlled to have an exhaust air amount of not less than 4.5 m 3 / min.

3. The method for producing bread-aroma-possessing amber roasty malt according to Claim 1, characterized by, the method further comprises a selection step before the germination step, and the selection step comprises selecting Copeland malted barley, Synergy malted barley or Metcalfe malted barley as the raw material for malting.

4. A bread-aroma having amber-roasted malt, characterized by, obtained by the method for preparing bread-aroma amber-roasted malt according to any one of claims 1-3.

5. A beer characterized in that, obtained by the method for brewing bread-aroma amber-roasted malt according to claim 4.

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