An amber-colored crystalline malt with both caramel and bread aromas, its preparation method, and beer.

Abstract

This invention discloses an amber-colored crystalline malt with both caramel and bread aromas, its preparation method, and beer, belonging to the field of malt manufacturing. The method includes a germination step and a roasting step. The germination temperature in the third germination stage is higher than that in the second germination stage, and the germination temperature in the second germination stage is higher than that in the first germination stage. The high-temperature hydration roasting process in the roasting step includes: after a low-temperature roasting process, rapidly raising the roasting temperature to 140-145°C and performing a first spray hydration; after the first spray hydration, lowering the roasting temperature below 140°C; and when the roasting temperature rises to 140°C, performing a second spray hydration. This invention is applied to the manufacture of specialty malts, solving the problem that existing crystalline malts have a relatively simple flavor, only imparting a rich caramel aroma to the beer and failing to highlight the complex and full-bodied bread aroma of specialty beers, thus obtaining an amber-colored crystalline malt with both caramel and bread aromas.

Description

Technical Field

[0001] This invention belongs to the field of malt manufacturing, and particularly relates to an amber crystal malt with both caramel and bread aromas, its preparation method, and beer. Background Technology

[0002] China's beer market is the world's largest beer consumption market. With the trend of consumption upgrading, the mid-to-high-end market is constantly increasing. However, domestic beer cannot meet the high-end and diversified consumption demands, which has led to imported beer rapidly seizing the mid-to-high-end market.

[0003] Specialty malts impart characteristic aromas and flavors to beer, making them key to differentiated product innovation. Crystallized malt, as an important category of specialty malts, is widely used in the brewing of specialty beers. It not only imparts a distinct malt aroma to the beer but also enhances its body, resulting in a richer and fuller flavor.

[0004] However, the flavor of crystallized malt produced by existing preparation technologies is relatively simple, only able to impart a rich caramel aroma to the beer, and unable to highlight the complex and full-bodied bread aroma of specialty beers. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the technical problem to be solved by the present invention is to overcome the problem that the crystalline malt produced by the existing preparation technology has a relatively simple flavor, which can only give the liquid a rich caramel aroma and cannot highlight the complex and full bread aroma of specialty beer. The present invention proposes an amber crystal malt with rich malt aroma, rich caramel aroma and bread aroma, clean and harmonious body, and no off-flavors such as burnt or charred taste, as well as its preparation method and beer.

[0006] To solve the aforementioned technical problem, the technical solution adopted by the present invention is as follows:

[0007] This invention provides a method for preparing amber-crystal malt with both caramel and bread aromas, comprising a germination step and a roasting step. The germination step includes: 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 roasting step includes: a low-temperature roasting process and a high-temperature hydration roasting process; the high-temperature hydration roasting process includes: after the low-temperature roasting process, rapidly raising the roasting temperature to 140-145°C and performing a first spray hydration; after the first spray hydration, lowering the roasting temperature below 140°C; and when the roasting temperature rises to 140°C, performing a second spray hydration; the amount of water added in the first spray hydration is less than the amount added in the second spray hydration.

[0008] Preferably, the germination temperature of the first germination stage is any value between 12-13℃; the germination temperature of the second germination stage is any value between 14-16℃; and the germination temperature of the third germination stage is any value between 17-18℃.

[0009] Preferably, the amount of water replenished by the first spray is 50-80 mL / kg, and the amount of water replenished by the second spray is 200-300 mL / kg.

[0010] Preferably, the low-temperature roasting process includes: in the initial stage of roasting, controlling the green malt to be put into the oven with a moisture content of 12-15%, the low-temperature roasting temperature is 95-100℃, and the low-temperature roasting time is 120-140min.

[0011] Preferably, the process also includes a protein resting step after the germination step, wherein the moisture content of the green malt after the protein resting step is any value between 12% and 15%.

[0012] In a preferred embodiment, the process further includes a protein resting step following the germination step, wherein the moisture content of the green malt after the protein resting step is any value between 12% and 15%. This technical solution further limits the moisture content of the green malt after the protein resting step because, during the preparation of crystalline malt, a high moisture content promotes the formation of 2,5-dimethyl-4-hydroxy-3(2H)-furanone (DMHF), resulting in a lower content of 2-acetylpyrrole (2-AP). Therefore, it is necessary to reduce the moisture content to promote the formation of a large amount of 2-AP. The subsequent roasting process simultaneously obtains a high DMHF content through a water spraying process. It is understood that the moisture content of the green malt can also be any value within the range of 13%, 14%, or similar values.

[0013] Preferably, the exhaust volume during the protein resting step is controlled to be no less than 4.5 m³. 3 / min.

[0014] Preferably, the protein resting step is performed at a resting temperature of 50°C for 40 minutes.

[0015] Preferably, the process also includes a wheat selection step prior to the germination step, wherein the wheat selection step includes selecting Copeland and / or Synergy and / or Metcalfe as wheat-producing raw materials.

[0016] Another aspect of the present invention provides an amber crystal malt with both caramel and bread aromas, which is prepared by the preparation method of the amber crystal malt with both caramel and bread aromas described in any of the above technical solutions.

[0017] The present invention also provides a beer brewed from amber crystal malt with both caramel and bread aromas as described in any of the above technical solutions.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] This invention provides a method for preparing amber-colored crystalline malt with both caramel and bread aromas. The method employs a gradient temperature germination process to promote the generation of key amino acids. First, the 2-AP content is maximized by reducing the moisture content upon entering the oven and extending the roasting time. Then, a high-temperature extreme water replenishment process (i.e., a high-temperature water replenishment roasting process) is used to further promote the generation of DMHF, ultimately obtaining crystalline malt with high 2-AP and high DMHF content. Detailed Implementation

[0020] The technical solutions in specific embodiments of the present invention will be described in detail and completely below. Obviously, the described embodiments are only some specific implementations of the overall technical solution of the present invention, and not all implementations. Based on the overall concept of the present invention, all other embodiments obtained by those skilled in the art fall within the protection scope of the present invention.

[0021] This invention provides a method for preparing amber-crystal malt with both caramel and bread aromas, comprising a germination step and a roasting step. The germination step includes: 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 roasting step includes: a low-temperature roasting process and a high-temperature hydration roasting process; the high-temperature hydration roasting process includes: after the low-temperature roasting process, rapidly raising the roasting temperature to 140-145°C and performing a first spray hydration; after the first spray hydration, lowering the roasting temperature below 140°C; and when the roasting temperature rises to 140°C, performing a second spray hydration; the amount of water added in the first spray hydration is less than the amount added in the second spray hydration. Caramel aroma is a typical aroma characteristic of crystalline malt and crystal malt, and it is closely related to the DMHF content of the malt. Current preparation techniques mainly increase the DMHF content by increasing the initial moisture content and roasting temperature. However, bread aroma requires reducing the initial moisture content and extending the roasting time to achieve a high 2-AP content. Therefore, existing preparation processes cannot simultaneously control the moisture content and increase the content of both aroma compounds during the roasting process, thus failing to produce amber-colored crystalline malt with both caramel and bread aromas. This invention employs a gradient temperature germination process to promote the formation of key amino acids. First, it maximizes the 2-AP content by reducing the initial moisture content and extending the roasting time. Then, it uses a high-temperature extreme hydration process (i.e., a high-temperature hydration roasting process) to further promote DMHF formation, ultimately obtaining crystalline malt with high 2-AP and high DMHF content, which possesses both caramel and bread aromas. Regarding the relevant processes, specifically, a gradient temperature process is used during germination. In the early stage of germination, low temperature germination further promotes the generation of hydrolytic enzymes. In the middle and late stages of germination, the germination temperature is gradually increased, which can effectively promote protein decomposition, increase glycine (high glycine content is conducive to the generation of DMHF) and total serine (high serine content is conducive to the generation of 2-AP), increase the content of specific amino acids, and promote the production of caramel and caramel aromas, thus helping to obtain crystalline malt with high caramel and bread aromas. In the early stage of baking, in order to ensure the bread aroma of the malt, the green malt is controlled to be put into the oven with low moisture content and baked at a low baking temperature, thereby obtaining crystalline malt with high 2-AP content. However, because the green malt has low moisture content and low baking temperature, the DMHF content of the crystalline malt is affected, resulting in a lower DMHF content that cannot meet the taste requirements of caramel aroma.Therefore, this technical solution adopts the method of rapidly raising the roasting temperature to 140-145℃ and performing two spray water replenishment processes. This process mainly involves high-temperature extreme water replenishment to promote the formation of furanone, and finally obtain crystalline malt with high caramel aroma and high bread aroma.

[0022] It should be noted that the technical solution of this application limits the high-temperature hydration roasting process to two hydration cycles. This is because a single large-volume hydration will cause high local moisture content in the malt, leading to sugar overflow and rupture of the malt grains, resulting in burnt substances at high temperatures and affecting the purity of the malt aroma. Simultaneously, this technical solution also limits the amount of water added in the first spray hydration to be less than that in the second spray hydration. This is because the first small-volume hydration primarily increases the humidity of the malt surface, promoting the reaction of more reactive pentose sugars with amino acids to form furanones, while the second large-volume hydration primarily increases the humidity of the endosperm, promoting further reaction of hexose sugars with amino acids to form furanones. Furthermore, this technical solution limits the roasting temperature of the high-temperature hydration roasting process to no more than 140℃. This is because excessively high roasting temperatures easily produce pyrazines and other substances with burnt flavors, affecting the purity of the aroma.

[0023] In a preferred embodiment, the germination temperature of the first germination stage is any value between 12-13℃; the germination temperature of the second germination stage is any value between 14-16℃; and the germination temperature of the third germination stage is any value between 17-18℃. This technical solution further specifies the germination temperatures of the first, second, and third germination stages because the amino acid composition of different barley varieties does not differ significantly at the same germination temperature, while the amino acid content and composition of the same barley variety differ significantly after preparation at different germination temperatures. The gradient temperature process used here is to increase the content of glycine and serine, thereby enhancing the caramel and bread aromas.

[0024] In a preferred embodiment, the amount of water replenished by the first spray is 50-80 mL / kg, and the amount of water replenished by the second spray is 200-300 mL / kg. This technical solution further defines the amounts of water replenished by the first and second sprays. It is understood that the amount of water replenished by the first spray can also be any value within the range of 55 mL / kg, 60 mL / kg, 65 mL / kg, 70 mL / kg, 75 mL / kg, and the amount of water replenished by the second spray can also be any value within the range of 220 mL / kg, 240 mL / kg, 260 mL / kg, 280 mL / kg.

[0025] In a preferred embodiment, the low-temperature baking process includes: initially, controlling the green malt to have a moisture content of 12-15% when it is introduced into the oven; the low-temperature baking temperature is 95-100℃; and the low-temperature baking time is 120-140 minutes. This technical solution specifically defines the moisture content of the green malt entering the oven, the baking temperature, and the baking time during the low-temperature baking process, effectively ensuring the formation of 2-AP and preserving the bread aroma of the malt. It is understood that the baking temperature can also be any value within the range of 96℃, 97℃, 98℃, 99℃, and the baking time can also be any value within the range of 125 minutes, 130 minutes, 135 minutes, and so on.

[0026] In a preferred embodiment, the resting temperature of the protein resting step is 50°C, and the resting time is 40 minutes. This embodiment specifically defines the resting temperature and resting time of the protein resting step, which is beneficial for the carboxypeptidase in malt to decompose polypeptides into amino acids and for the endopeptidase to decompose proteins into polypeptides and amino acids, thereby promoting the production of glycine and serine.

[0027] In a preferred embodiment, the process further includes a malt selection step prior to the germination step. This malt selection step includes selecting Copeland and / or Synergy and / or Metcalfe malts as raw materials for malting. This technical solution specifically limits the types of malt selected because the caramel and bread aromas of malt mainly originate from the Maillard reaction between carbonyl and amino groups. Since the content of sugars in barley grains is much higher than that of nitrogenous substances, it is necessary to select high-protein barley varieties from the source to promote the formation of aroma compounds.

[0028] Another aspect of the present invention provides an amber-crystal malt with both caramel and bread aromas, prepared by the method for preparing amber-crystal malt with both caramel and bread aromas as described in any of the above technical solutions. This amber-crystal malt possesses high caramel and bread aromas; when applied to beer brewing, sensory evaluation reveals a rich malt aroma, abundant caramel and bread aromas, a clean and harmonious body, and no off-flavors such as burnt or scorched tastes.

[0029] This invention also provides a beer brewed from amber-crystal malt with both caramel and bread aromas, as described in any of the above technical solutions. Sensory evaluation of this beer reveals a rich malt aroma, abundant caramel and bread aromas, a clean and harmonious body, and no off-flavors such as burnt or scorched tastes.

[0030] To more clearly and in detail introduce the amber crystal malt with both caramel and bread aromas, its preparation method, and beer provided by the embodiments of the present invention, the following description will be based on specific embodiments.

[0031] Example 1

[0032] 1. Amber crystal malt with aromas of caramel and bread - Copeland

[0033] (1) Selection of barley: Copeland barley with a protein content of 12.3% was selected as raw material. The barley grains were plump and the barley germination rate was 99%.

[0034] (2) Raw material pretreatment: The barley is cleaned to remove straw, bag ropes, wood blocks, iron nails, screws, metal wires, stones, miscellaneous barley grains, broken barley grains, etc.; and it is screened and graded to retain barley with a uniform size of 2.5mm-2.8mm in length.

[0035] (3) Soaking the barley: Add soaking water to the soaking tank, and then feed the barley into the soaking tank. A small portion of the floating barley and impurities that float to the surface are collected through the collection port to complete the floating barley operation. After the floating barley is finished, change the water quality and use the three-soaking and two-stopping low-temperature long-term soaking and water-stopping method at a water temperature of 15℃. The soaking process includes the first wet soaking stage (wet soaking for 5 hours), the first dry soaking stage (dry soaking for 15 hours), the second wet soaking stage (wet soaking for 7 hours), the second dry soaking stage (dry soaking for 11 hours), and the third wet soaking stage (wet soaking for 2 hours). The final soaking degree reaches 45%. Continuous ventilation and oxygen supply are used during the soaking process.

[0036] (4) Germination: The germination process is carried out in a ventilated germination device, with the germination temperature controlled at 12-18℃, and the germination time is 96 hours. The first germination stage is from 0 to 12 hours, with a germination temperature of 12℃; the second germination stage is from 12 to 72 hours, with a germination temperature of 14℃; and the third germination stage is from 72 to 96 hours, with a germination temperature of 17℃. The first stirring time for germination is 12-20 hours after the end of feeding. During the early germination and wilting stages, the wheat is turned every 10-12 hours, and during the vigorous germination stage, it is turned every 6-9 hours. At the end of germination, the average leaf bud length is 4 / 5-5 / 5 of the wheat grain length, accounting for 95% of the total germination, and the germination rate reaches 99%.

[0037] (5) Green malt protein resting: Place green malt in a roasting oven, and heat the oven at a uniform rate of 1.5-2.0℃ / min. After the temperature reaches 50℃, allow the protein to rest at a constant temperature for 40 minutes. At the end of the resting process, the glycine content is 168 mg / L and the serine content is 232 mg / L. Simultaneously, control the oven exhaust volume to 4.5 m³ / min. 3 At a rate of / min, the moisture content of the green malt protein at the end of the resting phase is 15%. This process involves using low temperature and high air volume to remove moisture from the green malt, promoting wilting, reducing enzyme damage, and further promoting amino acid formation. If the exhaust volume is low, the dehydration rate will inevitably be slow, making the malt prone to developing a raw, grassy taste and affecting the purity of the aroma.

[0038] (6) Green malt saccharification: After the protein resting period, the green malt is heated to 65°C at a constant rate of 4°C / h and saccharified at a constant temperature for 60 min.

[0039] (7) Baking: After saccharification, increase the speed of the baking oven to 8 r / min and quickly heat it to 100℃ for 120 min. Then, heat the baking oven to 145℃ again and add water for the first time, with a water volume of 50 ml / kg. After the temperature rises to 140℃ again, add water for the second time, with a water volume of 200 ml / kg.

[0040] (8) Root removal: The malt obtained in step (7) is immediately rooted to obtain an amber crystal malt with both caramel and bread aroma.

[0041] The physicochemical properties, DMHF content, 2-AP content, and sensory evaluation results of the malt prepared through the above steps are shown in Tables 1, 2, and 3.

[0042] Table 1 Physicochemical Indicators of Malt

[0043]

[0044]

[0045] Table 2. DMHF and 2-AP content in wort

[0046] Components unit ordinary malt Malt prepared in Example 1 Purchased crystallized malt DMHF mg / kg 4.1 67.2 25.3 2-AP ug / L ND 289 94

[0047] Table 3 Sensory Evaluation Results of Wheat Gravy

[0048]

[0049] 2. Beers with high caramel and bread aromas

[0050] The brewing raw materials used 70% Pilsner malt and added 30% Copeland malt prepared in Example 1. The physicochemical indicators of the brewed wine met the GB / T 4927-2008 standard. The sensory evaluation results of the national-level wine tasters are shown in Table 4.

[0051] Table 4 Sensory Evaluation Results of Finished Wine

[0052]

[0053] Example 2

[0054] 1. Amber crystal malt with caramel and bread aromas - Synergy

[0055] (1) Selection of barley: Synergy barley with a protein content of 12.6% was selected as raw material. The barley grains were plump and the barley germination rate was 99%.

[0056] (2) Raw material pretreatment: The barley is cleaned to remove straw, bag ropes, wood blocks, iron nails, screws, metal wires, stones, miscellaneous barley grains, broken barley grains, etc.; and it is screened and graded to retain barley with a uniform size of 2.5mm-2.8mm in length.

[0057] (3) Soaking the barley: Add soaking water to the soaking tank, and then feed the barley into the soaking tank. A small portion of the floating barley and impurities that float to the surface are collected through the collection port to complete the floating barley operation. After the floating barley is finished, change the water quality and use the three-soaking and two-stopping low-temperature long-term soaking and water-stopping method at a water temperature of 15℃. The soaking process includes the first wet soaking stage (wet soaking for 5 hours), the first dry soaking stage (dry soaking for 15 hours), the second wet soaking stage (wet soaking for 7 hours), the second dry soaking stage (dry soaking for 11 hours), and the third wet soaking stage (wet soaking for 2 hours). The final soaking degree reaches 45%. Continuous ventilation and oxygen supply are used during the soaking process.

[0058] (4) Germination: The germination process is carried out in a ventilated germination device, with the germination temperature controlled at 12-18℃, and the germination time is 96 hours. The first germination stage is from 0-12 hours, with a germination temperature of 13℃; the second germination stage is from 12-72 hours, with a germination temperature of 16℃; and the third germination stage is from 72-96 hours, with a germination temperature of 18℃. The first stirring time for germination is 12-20 hours after the end of feeding. During the early germination and wilting stages, the wheat is turned every 10-12 hours, and during the vigorous germination stage, it is turned every 6-9 hours. At the end of germination, the average leaf bud length is 4 / 5-5 / 5 of the wheat grain length, accounting for 95% of the total germination, and the germination rate reaches 99%.

[0059] (5) Green malt protein resting: Place green malt in a roasting oven, and heat the oven at a uniform rate of 1.5-2.0℃ / min. After the temperature reaches 50℃, allow the protein to rest at a constant temperature for 40 minutes. At the end of the resting process, the glycine content is 154 mg / L and the serine content is 228 mg / L. Simultaneously, control the oven exhaust volume to 4.7 m³ / min. 3 At a rate of / min, the moisture content of the green malt protein at the end of the resting phase is 12%. This process involves using low temperature and high air volume to remove moisture from the green malt, promoting wilting, reducing enzyme damage, and further promoting amino acid formation. If the exhaust volume is low, the dehydration rate will inevitably be slow, making the malt prone to developing a raw, grassy taste and affecting the purity of the aroma.

[0060] (6) Green malt saccharification: After the protein resting period, the green malt is heated to 65°C at a constant rate of 4°C / h and saccharified at a constant temperature for 60 min.

[0061] (7) Baking: After saccharification, increase the speed of the baking oven to 8 r / min and quickly heat it to 95℃ for 140 min. Then, heat the baking oven to 143℃ again and add water for the first time, with a water volume of 80 ml / kg. After the temperature rises to 140℃ again, add water for the second time, with a water volume of 300 ml / kg.

[0062] (8) Root removal: The malt obtained in step (7) is immediately rooted to obtain an amber crystal malt with both caramel and bread aroma.

[0063] The physicochemical properties, DMHF content, 2-AP content, and sensory evaluation results of the malt prepared through the above steps are shown in Tables 5, 6, and 7.

[0064] Table 5 Physicochemical Indicators of Malt

[0065]

[0066]

[0067] Table 6. Wort DMHF and 2-AP Content

[0068] Components unit ordinary malt Malt prepared in Example 2 Purchased crystallized malt DMHF mg / kg 4.1 73.8 25.3 2-AP ug / L ND 273 94

[0069] Table 7 Sensory Evaluation Results of Wheat Gravy

[0070]

[0071] 2. Beers with high caramel and bread aromas

[0072] The brewing raw materials used 70% Pilsner malt and added 30% of the malted Synergy prepared in Example 2. The physicochemical indicators of the brewed wine met the GB / T 4927-2008 standard. The sensory evaluation results of the national-level wine tasters are shown in Table 8.

[0073] Table 8 Sensory Evaluation Results of Finished Wine

[0074]

[0075] Example 3

[0076] 1. Amber crystal malt with caramel and bread aromas - Metcalfe

[0077] (1) Selection of barley: Metcalfe barley with a protein content of 11.7% was selected as raw material. The barley grains were plump and the barley germination rate was 99%.

[0078] (2) Raw material pretreatment: The barley is cleaned to remove straw, bag ropes, wood blocks, iron nails, screws, metal wires, stones, miscellaneous barley grains, broken barley grains, etc.; and it is screened and graded to retain barley with a uniform size of 2.5mm-2.8mm in length.

[0079] (3) Soaking the barley: Add soaking water to the soaking tank, and then feed the barley into the soaking tank. A small portion of the floating barley and impurities that float to the surface are collected through the collection port to complete the floating barley operation. After the floating barley is finished, change the water quality and use the three-soaking and two-stopping low-temperature long-term soaking and water-stopping method at a water temperature of 15℃. The soaking process includes the first wet soaking stage (wet soaking for 5 hours), the first dry soaking stage (dry soaking for 15 hours), the second wet soaking stage (wet soaking for 7 hours), the second dry soaking stage (dry soaking for 11 hours), and the third wet soaking stage (wet soaking for 2 hours). The final soaking degree reaches 45%. Continuous ventilation and oxygen supply are used during the soaking process.

[0080] (4) Germination: The germination process is carried out in a ventilated germination device, with the germination temperature controlled at 12-18℃, and the germination time is 96 hours. The first germination stage is from 0-12 hours, with a germination temperature of 13℃; the second germination stage is from 12-72 hours, with a germination temperature of 16℃; and the third germination stage is from 72-96 hours, with a germination temperature of 18℃. The first stirring time for germination is 12-20 hours after the end of feeding. During the early germination and wilting stages, the wheat is turned every 10-12 hours, and during the vigorous germination stage, it is turned every 6-9 hours. At the end of germination, the average leaf bud length is 4 / 5-5 / 5 of the wheat grain length, accounting for 95% of the total germination, and the germination rate reaches 99%.

[0081] (5) Green malt protein resting: Place green malt in a roasting oven, and heat the oven at a uniform rate of 1.5-2.0℃ / min. After the temperature reaches 50℃, allow the protein to rest at a constant temperature for 40 minutes. At the end of the resting process, the glycine content is 164 mg / L and the serine content is 216 mg / L. Simultaneously, control the oven exhaust volume to 4.7 m³ / min. 3 At a rate of / min, the moisture content of the green malt protein at the end of the resting phase is 14%. This process involves using low temperature and high air volume to remove moisture from the green malt, promoting wilting, reducing enzyme damage, and further promoting amino acid formation. If the exhaust volume is low, the dehydration rate will inevitably be slow, making the malt prone to developing a raw, grassy taste and affecting the purity of the aroma.

[0082] (6) Green malt saccharification: After the protein resting period, the green malt is heated to 65°C at a constant rate of 4°C / h and saccharified at a constant temperature for 60 min.

[0083] (7) Baking: After saccharification, increase the speed of the baking oven to 8 r / min and quickly heat it to 98℃ for 135 min. Then, heat the baking oven to 140℃ again and add water for the first time, with a water volume of 60 ml / kg. After the temperature rises to 140℃ again, add water for the second time, with a water volume of 240 ml / kg.

[0084] (8) Root removal: The malt obtained in step (7) is immediately rooted to obtain an amber crystal malt with both caramel and bread aroma.

[0085] The physicochemical properties, DMHF content, 2-AP content, and sensory evaluation results of the malt prepared through the above steps are shown in Tables 9, 10, and 11.

[0086] Table 9 Physicochemical Indicators of Malt

[0087]

[0088] Table 10. DMHF and 2-AP content in wort

[0089] Components unit ordinary malt Malt prepared in Example 3 Purchased crystallized malt DMHF mg / kg 4.1 69.2 25.3 2-AP ug / L ND 258 94

[0090] Table 11 Sensory Evaluation Results of Wheat Gravy

[0091]

[0092] 2. Beers with high caramel and bread aromas

[0093] The brewing raw materials used 70% Pilsner malt and added 30% Metcalfe malt prepared in Example 3. The physicochemical indicators of the brewed wine met the GB / T 4927-2008 standard. The sensory evaluation results of the national-level wine tasters are shown in Table 12.

[0094] Table 12 Sensory Evaluation Results of Finished Wine

[0095]

[0096] Comparative Example 1

[0097] Same as Example 1, except that a constant-temperature germination process is used. Specifically:

[0098] 1. Amber crystal malt with aromas of caramel and bread - Copeland

[0099] (1) Selection of barley: Copeland barley with a protein content of 12.3% was selected as raw material. The barley grains were plump and the barley germination rate was 99%.

[0100] (2) Raw material pretreatment: The barley is cleaned to remove straw, bag ropes, wood blocks, iron nails, screws, metal wires, stones, miscellaneous barley grains, broken barley grains, etc.; and it is screened and graded to retain barley with a uniform size of 2.5mm-2.8mm in length.

[0101] (3) Soaking the barley: Add soaking water to the soaking tank, and then feed the barley into the soaking tank. A small portion of the floating barley and impurities that float to the surface are collected through the collection port to complete the floating barley operation. After the floating barley is finished, change the water quality and use the three-soaking and two-stopping low-temperature long-term soaking and water-stopping method at a water temperature of 15℃. The soaking process includes the first wet soaking stage (wet soaking for 5 hours), the first dry soaking stage (dry soaking for 15 hours), the second wet soaking stage (wet soaking for 7 hours), the second dry soaking stage (dry soaking for 11 hours), and the third wet soaking stage (wet soaking for 2 hours). The final soaking degree reaches 45%. Continuous ventilation and oxygen supply are used during the soaking process.

[0102] (4) Germination: The germination process is carried out in a ventilated germination device, with the temperature controlled at 16℃ from 0 to 96 hours. The first stirring time for germination is 12-20 hours after the end of feeding. During the early germination and wilting stages, the wheat is turned every 10-12 hours, and during the vigorous germination stage, it is turned every 6-9 hours. At the end of germination, the average leaf bud length is 4 / 5-5 / 5 of the wheat grain length, accounting for 95% of the total malt, and the germination rate reaches 99%.

[0103] (5) Green malt protein resting: Place green malt in a roasting oven, and heat the oven at a uniform rate of 1.5-2.0℃ / min. After the temperature reaches 50℃, allow the protein to rest at a constant temperature for 40 minutes. At the end of the resting process, the glycine content is 79 mg / L and the serine content is 102 mg / L. Simultaneously, control the oven exhaust volume to 4.5 m³ / min. 3 At a rate of / min, the moisture content of the green malt protein at the end of the resting phase is 15%. This process involves using low temperature and high air volume to remove moisture from the green malt, promoting wilting, reducing enzyme damage, and further promoting amino acid formation. If the exhaust volume is low, the dehydration rate will inevitably be slow, making the malt prone to developing a raw, grassy taste and affecting the purity of the aroma.

[0104] (6) Green malt saccharification: After the protein resting period, the green malt is heated to 65°C at a constant rate of 4°C / h and saccharified at a constant temperature for 60 min.

[0105] (7) Baking: After saccharification, increase the speed of the baking oven to 8 r / min and quickly heat it to 100℃ for 120 min. Then, heat the baking oven to 145℃ again and add water for the first time, with a water volume of 50 ml / kg. After the temperature rises to 140℃ again, add water for the second time, with a water volume of 200 ml / kg.

[0106] (8) Root removal: The malt obtained in step (7) is immediately rooted to obtain amber crystal malt.

[0107] Comparative Example 2

[0108] Same as Example 1, except that a cooling germination process is used. Specifically:

[0109] 1. Amber crystal malt with aromas of caramel and bread - Copeland

[0110] (1) Selection of barley: Copeland barley with a protein content of 12.3% was selected as raw material. The barley grains were plump and the barley germination rate was 99%.

[0111] (2) Raw material pretreatment: The barley is cleaned to remove straw, bag ropes, wood blocks, iron nails, screws, metal wires, stones, miscellaneous barley grains, broken barley grains, etc.; and it is screened and graded to retain barley with a uniform size of 2.5mm-2.8mm in length.

[0112] (3) Soaking the barley: Add soaking water to the soaking tank, and then feed the barley into the soaking tank. A small portion of the floating barley and impurities that float to the surface are collected through the collection port to complete the floating barley operation. After the floating barley is finished, change the water quality and use the three-soaking and two-stopping low-temperature long-term soaking and water-stopping method at a water temperature of 15℃. The soaking process includes the first wet soaking stage (wet soaking for 5 hours), the first dry soaking stage (dry soaking for 15 hours), the second wet soaking stage (wet soaking for 7 hours), the second dry soaking stage (dry soaking for 11 hours), and the third wet soaking stage (wet soaking for 2 hours). The final soaking degree reaches 45%. Continuous ventilation and oxygen supply are used during the soaking process.

[0113] (4) Germination: The germination process is carried out in a ventilated germination device, with the germination temperature controlled at 12-18℃, and the germination time is 96 hours. The first germination stage is from 0-12 hours, with a germination temperature of 17℃; the second germination stage is from 12-72 hours, with a germination temperature of 14℃; and the third germination stage is from 72-96 hours, with a germination temperature of 12℃. The first stirring time for germination is 12-20 hours after the end of feeding. During the early germination and wilting stages, the wheat is turned every 10-12 hours, and during the vigorous germination stage, it is turned every 6-9 hours. At the end of germination, the average leaf bud length is 4 / 5-5 / 5 of the wheat grain length, accounting for 95% of the total germination, and the germination rate reaches 99%.

[0114] (5) Green malt protein resting: Place green malt in a roasting oven, and heat the oven at a uniform rate of 1.5-2.0℃ / min. After the temperature reaches 50℃, allow the protein to rest at a constant temperature for 40 minutes. At the end of the resting process, the glycine content is 88 mg / L and the serine content is 117 mg / L. Simultaneously, control the oven exhaust volume to 4.5 m³ / min. 3At a rate of / min, the moisture content of the green malt protein at the end of the resting phase is 15%. This process involves using low temperature and high air volume to remove moisture from the green malt, promoting wilting, reducing enzyme damage, and further promoting amino acid formation. If the exhaust volume is low, the dehydration rate will inevitably be slow, making the malt prone to developing a raw, grassy taste and affecting the purity of the aroma.

[0115] (6) Green malt saccharification: After the protein resting period, the green malt is heated to 65°C at a constant rate of 4°C / h and saccharified at a constant temperature for 60 min.

[0116] (7) Baking: After saccharification, increase the speed of the baking oven to 8 r / min and quickly heat it to 100℃ for 120 min. Then, heat the baking oven to 145℃ again and add water for the first time, with a water volume of 50 ml / kg. After the temperature rises to 140℃ again, add water for the second time, with a water volume of 200 ml / kg.

[0117] (8) Root removal: The malt obtained in step (7) is immediately rooted to obtain amber crystal malt.

[0118] Comparative Example 3

[0119] Same as Example 1, except that no water is added during the baking process. Specifically:

[0120] 1. Amber crystal malt with aromas of caramel and bread - Copeland

[0121] (1) Selection of barley: Copeland barley with a protein content of 12.3% was selected as raw material. The barley grains were plump and the barley germination rate was 99%.

[0122] (2) Raw material pretreatment: The barley is cleaned to remove straw, bag ropes, wood blocks, iron nails, screws, metal wires, stones, miscellaneous barley grains, broken barley grains, etc.; and it is screened and graded to retain barley with a uniform size of 2.5mm-2.8mm in length.

[0123] (3) Soaking the barley: Add soaking water to the soaking tank, and then feed the barley into the soaking tank. A small portion of the floating barley and impurities that float to the surface are collected through the collection port to complete the floating barley operation. After the floating barley is finished, change the water quality and use the three-soaking and two-stopping low-temperature long-term soaking and water-stopping method at a water temperature of 15℃. The soaking process includes the first wet soaking stage (wet soaking for 5 hours), the first dry soaking stage (dry soaking for 15 hours), the second wet soaking stage (wet soaking for 7 hours), the second dry soaking stage (dry soaking for 11 hours), and the third wet soaking stage (wet soaking for 2 hours). The final soaking degree reaches 45%. Continuous ventilation and oxygen supply are used during the soaking process.

[0124] (4) Germination: The germination process is carried out in a ventilated germination device, with the germination temperature controlled at 12-18℃, and the germination time is 96 hours. The first germination stage is from 0 to 12 hours, with a germination temperature of 12℃; the second germination stage is from 12 to 72 hours, with a germination temperature of 14℃; and the third germination stage is from 72 to 96 hours, with a germination temperature of 17℃. The first stirring time for germination is 12-20 hours after the end of feeding. During the early germination and wilting stages, the wheat is turned every 10-12 hours, and during the vigorous germination stage, it is turned every 6-9 hours. At the end of germination, the average leaf bud length is 4 / 5-5 / 5 of the wheat grain length, accounting for 95% of the total germination, and the germination rate reaches 99%.

[0125] (5) Green malt protein resting: Place green malt in a roasting oven, and heat the oven at a uniform rate of 1.5-2.0℃ / min. After the temperature reaches 50℃, allow the protein to rest at a constant temperature for 40 minutes. At the end of the resting process, the glycine content is 164 mg / L and the serine content is 228 mg / L. Simultaneously, control the oven exhaust volume to 4.5 m³ / min. 3 At a rate of / min, the moisture content of the green malt protein at the end of the resting phase is 15%. This process involves using low temperature and high air volume to remove moisture from the green malt, promoting wilting, reducing enzyme damage, and further promoting amino acid formation. If the exhaust volume is low, the dehydration rate will inevitably be slow, making the malt prone to developing a raw, grassy taste and affecting the purity of the aroma.

[0126] (6) Green malt saccharification: After the protein resting period, the green malt is heated to 65°C at a constant rate of 4°C / h and saccharified at a constant temperature for 60 min.

[0127] (7) Baking: After saccharification, increase the oven speed to 8 r / min and quickly heat to 100℃ for 120 min. Then, heat the oven to 145℃ again.

[0128] (8) Root removal: The malt obtained in step (7) is immediately rooted to obtain amber crystal malt.

[0129] Performance testing

[0130] Sensory evaluation and content detection were performed on the wort obtained in Examples 1-3 and Comparative Examples 1-3, and the results are shown in Table 13.

[0131] Table 13. Wort performance results obtained from Examples 1-3 and Comparative Examples 1-3

[0132]

Claims

1. A method for preparing amber-crystal malt with both caramel and bread aromas, comprising a germination step and a roasting step, characterized in that, The germination process includes: 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 in the third germination stage is higher than that in the second germination stage, and the germination temperature in the second germination stage is higher than that in the first germination stage. The baking steps include: a low-temperature baking process and a high-temperature water-replenishing baking process; The high-temperature water replenishment baking process includes: after the low-temperature baking process, the baking temperature is rapidly raised to 140-145℃, and the first water spray is performed. After the first water spray, the baking temperature drops below 140℃. When the baking temperature rises to 140℃, the second water spray is performed. The amount of water replenished in the first water spray is less than the amount of water replenished in the second water spray. The germination temperature for the first germination stage is any value between 12-13℃; the germination temperature for the second germination stage is any value between 14-16℃; and the germination temperature for the third germination stage is any value between 17-18℃. The low-temperature roasting process includes: in the initial stage of roasting, the green malt is put into the oven with a moisture content of 12-15% or less, the low-temperature roasting temperature is 95-100℃, and the low-temperature roasting time is 120-140 min.

2. The method for preparing amber-crystal malt with both caramel and bread aromas according to claim 1, characterized in that, The amount of water replenished during the first spray is 50-80 mL / kg, and the amount of water replenished during the second spray is 200-300 mL / kg.

3. The method for preparing amber-crystal malt with both caramel and bread aromas according to claim 1, characterized in that, It also includes a protein resting step after the germination step, wherein the moisture content of the green malt after the protein resting step is any value between 12% and 15%.

4. The method for preparing amber-crystal malt with both caramel and bread aromas according to claim 3, characterized in that, During the protein resting step, the exhaust volume is controlled to be no less than 4.5 m³. 3 / min.

5. The method for preparing amber-crystal malt with both caramel and bread aromas according to claim 3, characterized in that, The protein resting step is performed at a resting temperature of 50°C for 40 minutes.

6. The method for preparing amber-crystal malt with both caramel and bread aromas according to claim 1, characterized in that, It also includes a wheat selection step before the germination step, which includes selecting at least one of Copeland, Synergy, and Metcalfe as wheat production raw materials.

7. An amber-crystal malt with both caramel and bread aromas, characterized in that, It is prepared by the method for preparing amber crystal malt with both caramel and bread aroma as described in any one of claims 1-6.

8. A beer, characterized in that, It is brewed from amber crystal malt with both caramel and bread aromas as described in claim 7.

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