Amber crystal malt having both caramel aroma and bread aroma, preparation method for amber crystal malt, and beer

Abstract

The present application discloses an amber crystal malt having both a caramel aroma and a bread aroma, a preparation method for the amber crystal malt, and beer. The preparation method comprises a germination step and a baking step. The germination temperature of a third germination stage in the germination step is higher than that of a second germination stage, and the germination temperature of the second germination stage is higher than that of a first germination stage. A high-temperature water supplementing baking process of the baking step comprises: after a low-temperature baking process, rapidly raising the baking temperature to 140-145ºC, and carrying out first spraying water supplementing; after the first spraying water supplementing, reducing the baking temperature to be less than 140ºC; and when the baking temperature is raised to 140ºC, carrying out second spraying water supplementing.

Description

Amber crystal malt with caramel aroma and bread aroma, preparation method thereof and beer

[0001] This application claims priority to a Chinese patent application filed with the Patent Office of China on February 7, 2024, with application number 2024101730700 and invention name “A kind of amber crystal malt with caramel aroma and bread aroma, its preparation method and beer”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application belongs to the field of malt manufacturing, and in particular relates to an amber crystal malt having both caramel aroma and bread aroma, a preparation method thereof, and beer. Background Art

[0003] Specialty malt imparts a characteristic aroma and taste to beer, making it key to differentiated product innovation. Crystallized malt, a key specialty malt category, is widely used in specialty beer brewing. It not only imparts a distinct malt aroma but also enhances the beer's body, resulting in a richer, fuller flavor. However, existing production technologies for crystallized malt offer a relatively monotonous flavor profile, making it difficult to meet market demand.

[0004] Summary of the Invention

[0005] In response to some shortcomings of the existing technology, the present application provides an amber crystal malt with both caramel aroma and bread aroma, a preparation method thereof, and beer.

[0006] In a first aspect, the present application provides a method for preparing amber crystal malt having both caramel aroma and bread aroma, comprising a germination step and a roasting step; wherein:

[0007] The germination step includes: a first germination stage of germination for 0-12 hours, a second germination stage of germination for 12-72 hours, and a third germination stage of germination for 72-96 hours; the germination temperature of the third germination stage is higher than the germination temperature of the second germination stage, and the germination temperature of the second germination stage is higher than the germination temperature of the first germination stage;

[0008] The baking steps include: a low-temperature baking process and a high-temperature water-replenishing baking process; wherein, the high-temperature water-replenishing baking process includes: after the low-temperature baking process, quickly raising the baking temperature to 140-145°C and performing a first spray water replenishment; after the first spray water replenishment, the baking temperature drops to below 140°C; when the baking temperature rises to 140°C, a second spray water replenishment is performed; the water replenishment amount of the first spray water replenishment is less than the water replenishment amount of the second spray water replenishment.

[0009] In one embodiment, the germination temperature of the first germination stage is any value between 12-13°C; the germination temperature of the second germination stage is any value between 14-16°C; and the germination temperature of the third germination stage is any value between 17-18°C.

[0010] In one embodiment, the water replenishment amount of the first spray replenishment is 50-80 mL / kg, and the water replenishment amount of the second spray replenishment is 200-300 mL / kg.

[0011] In one embodiment, the low-temperature roasting process includes: at the initial stage of the low-temperature roasting process, controlling the moisture content of the green malt to any value between 12% and 15%, the low-temperature roasting temperature to 95-100° C., and the low-temperature roasting time to 120-140 minutes.

[0012] In one embodiment, after the low-temperature baking process, the baking temperature is raised to 140-145° C. within 25 minutes.

[0013] In one embodiment, the preparation method further includes a protein rest step after the germination step, wherein the moisture content of the green malt after the protein rest step is any value between 12% and 15%. This embodiment further limits the moisture content of the green malt after the protein rest step. This is because, during the preparation of crystallized malt, a high moisture content favors the formation of 2,5-dimethyl-4-hydroxy-3(2H)-furanone (DMHF), resulting in a low 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 uses a water spraying process to simultaneously achieve a high DMHF content. It is understood that the moisture content of the green malt can also be 13%, 14%, or any value within this range. The protein rest step is located between the germination step and the roasting step.

[0014] In one embodiment, the exhaust volume is controlled to be no less than 4.5m 3 / min.

[0015] In one embodiment, the resting temperature of the protein resting step is 50° C., and the resting time is 40 min.

[0016] In one embodiment, the preparation method further includes a barley selection step before the germination step; the barley selection step includes selecting one of the following barleys as the malting raw material: Copeland barley, Synergy barley, and Metcalfe barley.

[0017] In a second aspect, the present application provides an amber crystal malt having both caramel aroma and bread aroma, which is prepared by the method for preparing the amber crystal malt having both caramel aroma and bread aroma described in any of the above embodiments.

[0018] A third aspect of the present application provides a beer, wherein the malt used in the brewing process of the beer is prepared by the preparation method of the amber crystal malt having both caramel aroma and bread aroma described in any of the above embodiments.

[0019] A fourth aspect of the present application provides a beer brewed from the amber crystalline malt having both caramel and bread aromas as described in any of the above embodiments.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] At least one embodiment of the present application provides a method for preparing amber crystallized malt with both caramel and bread aromas, which adopts a gradient temperature germination process to promote the production of key amino acids. The 2-AP content is first maximized by reducing the moisture content entering the furnace and extending the roasting time. Then, a high-temperature extreme hydration process (i.e., a high-temperature hydration roasting process) is used to further promote the production of DMHF, ultimately obtaining crystallized malt with high 2-AP and high DMHF content.

[0022] The malt preparation method provided by at least one embodiment of the present application can obtain amber crystal malt and beer with rich aroma, rich caramel aroma and bread aroma, clean and harmonious body, and no foreign flavor characteristics such as burnt smell and paste smell. DETAILED DESCRIPTION

[0023] The technical solutions in the specific embodiments of the present application are described in detail and completely below. Obviously, the described embodiments are only some specific embodiments of the overall technical solution of the present application, and not all embodiments. Based on the overall concept of the present application, all other embodiments obtained by those of ordinary skill in the art fall within the scope of protection of the present application.

[0024] The first embodiment of the present application provides a method for preparing amber crystal malt having both caramel and bread aromas, comprising a germination step and a roasting step. In particular:

[0025] 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 the germination temperature of the second germination stage, and the germination temperature of the second germination stage is higher than the germination temperature of the first germination stage. It will be understood by those skilled in the art that in actual operation, the time of each germination stage is not an absolute value, but can be fine-tuned at the time limit. For example, 11 hours and 55 minutes and 12 hours and 3 minutes can both be considered within the 12 hours of the first germination stage.

[0026] The baking step includes: a low-temperature baking process and a high-temperature water-replenishing baking process; the high-temperature water-replenishing baking process includes: after the low-temperature baking process, quickly raising the baking temperature to 140-145°C and performing a first spray water replenishment; after the first spray water replenishment, the baking temperature drops to below 140°C; when the baking temperature rises to 140°C, a second spray water replenishment is performed; the water replenishment amount of the first spray water replenishment is less than the water replenishment amount of the second spray water replenishment.

[0027] Baking is generally carried out in a baking oven, and the baking temperature is controlled by setting the temperature of the baking oven. There is a temperature range (approximately 40-50°C) between the low-temperature baking temperature and the high-temperature baking temperature. After the low-temperature baking process, the temperature is quickly raised from the low-temperature baking temperature to the high-temperature baking temperature within 25 minutes (for example, within 20-25 minutes, specifically 20 minutes, 22 minutes, 24 minutes, etc.). In addition, during the high-temperature water-replenishing baking process, the set temperature of the baking oven remains basically unchanged, but after spraying water, the temperature in the oven will drop briefly due to the absorption of heat by water vapor evaporation, and then return to the set temperature.

[0028] Caramel aroma is a typical aroma characteristic of crystal malt and crystal malt, which is closely related to the DMHF (4-hydroxy-2,5-dimethyl-3(2H)-furanone) content of the malt. In the existing preparation process, the DMHF content is mainly increased by increasing the moisture content entering the furnace and increasing the baking temperature; while the bread aroma requires reducing the moisture content entering the furnace and extending the baking time to obtain a high 2-AP (2-acetylpyrrole) content. Therefore, the existing preparation process cannot simultaneously control the moisture content and the baking process to simultaneously increase the content of two aroma substances, and thus it is impossible to prepare amber crystallized malt with both caramel aroma and bread aroma. This embodiment adopts a gradient temperature germination process to promote the production of key amino acids. First, the 2-AP content is maximized by reducing the moisture content entering the furnace and extending the baking time. Then, a high-temperature extreme hydration process (i.e., a high-temperature hydration baking process) is used to further promote the production of DMHF, and finally a crystallized malt with high 2-AP and high DMHF content is obtained. This crystallized malt has both caramel aroma and bread aroma. More specifically, the germination process utilizes a gradient temperature increase. Low-temperature germination in the early stages further promotes the production of hydrolytic enzymes, while gradually increasing the germination temperature in the middle and late stages. This effectively promotes protein breakdown, increases glycine (high glycine content favors the production of DMHF) and total serine (high serine content favors the production of 2-AP), and increases the content of specific amino acids. This promotes the development of caramel and bread aromas, contributing to the production of crystalline malt with high caramel and bread aromas. To ensure the malt's bready aroma, green malt is fed into the kiln at a low moisture content and roasted at a low temperature during the initial roasting process, resulting in crystalline malt with a high 2-AP content. However, due to the low moisture content of green malt entering the furnace and the low roasting temperature, the DMHF content of the crystallized malt is affected, resulting in a low DMHF content in the crystallized malt, which cannot meet the taste requirements of caramel aroma; therefore, this embodiment adopts the method of quickly raising the roasting temperature to 140-145°C and performing two spray water replenishment. This process mainly performs high-temperature extreme water replenishment to promote the formation of DMHF, and finally obtains crystallized malt with high caramel aroma and high bread aroma.

[0029] It should be noted that the present embodiment provides a technical solution for performing two water replenishment processes during the high-temperature water replenishment roasting process. The reason is that a one-time large-scale water replenishment will cause the local moisture content of the malt to be high, resulting in the sugar overflow and rupture of the grains, and the formation of burnt substances at high temperatures, which affects the purity of the malt aroma. The present embodiment limits the water replenishment amount of the first spray water replenishment to be less than the water replenishment amount of the second spray water replenishment. The reason is that the first small amount of water replenishment is mainly to increase the humidity of the malt surface, prompting the more active pentose sugars to react with amino acids to produce DMHF, and the second large amount of water replenishment is mainly to increase the humidity of the endosperm part, prompting the hexose sugars to further react with amino acids to produce DMHF. In addition, the present embodiment provides that the baking temperature of the high-temperature water replenishment roasting process does not exceed 145°C. The reason is that if the baking temperature is too high, it is easy to produce substances with a burnt smell such as pyrazines, which affect the purity of the aroma.

[0030] In the germination step, the germination temperature in the first germination stage is any value between 12-13°C, such as 12°C, 12.2°C, 12.5°C, 12.8°C, 13°C, etc.; the germination temperature in the second germination stage is any value between 14-16°C, such as 14°C, 14.5°C, 15°C, 15.5°C, 16°C, etc.; and the germination temperature in the third germination stage is any value between 17-18°C, such as 17°C, 17.2°C, 17.5°C, 17.8°C, 18°C, etc. The amino acid composition of different varieties of barley at the same germination temperature is not very different, but the amino acid content and composition of the same variety of barley prepared at different germination temperatures are significantly different; the gradient temperature increase process in the germination step is used to increase the content of glycine and serine, thereby enhancing the caramel aroma and bread aroma.

[0031] In one embodiment, the preparation method further includes a malt selection step before the germination step, wherein the malt selection step includes selecting Copeland, Synergy, and / or Metcalfe as the malting raw materials. The caramel and bread aromas of malt are primarily derived from the Maillard reaction between carbonyl and amino groups. Since the content of carbohydrates in wheat grains is far greater than that of nitrogenous substances, it is recommended to select barley varieties with high protein content from the source to promote the production of aromatic substances.

[0032] In one embodiment, the preparation method further includes a protein resting step between the germination step and the roasting step. After the germination step, the protein resting step begins. The resting temperature for this protein resting step is 50°C, and the resting time is 40 minutes. This step facilitates the breakdown of polypeptides into amino acids by carboxypeptidases in the malt, and the breakdown of proteins into polypeptides and amino acids by endopeptidases, thereby promoting the production of glycine and serine.

[0033] The low-temperature roasting process includes: at the initial stage of the low-temperature roasting process, controlling the green malt to enter the furnace with a moisture content of any value between 12-15wt%, the low-temperature roasting temperature is 95-100°C, and the low-temperature roasting time is 120-140 minutes. By limiting the moisture content, roasting temperature, and roasting time of the green malt entering the furnace during the low-temperature roasting process, the formation of 2-AP can be effectively guaranteed, ensuring the bread aroma of the malt. It is understood that the moisture content of the green malt when entering the furnace can be 12.5wt%, 13wt%, 13.5wt%, 14wt%, 14.5wt%, etc., and this moisture content can be controlled during the protein rest step; the roasting temperature can be 96°C, 97°C, 98°C, 99°C, and any value within the range; the roasting time can be 125 minutes, 130 minutes, 135 minutes, and any value within the range.

[0034] During the high-temperature water replenishment roasting process, the water replenishment amount of the first spray water replenishment is 50-80 mL / kg, and the water replenishment amount of the second spray water replenishment is 200-300 mL / kg. It is understandable that the water replenishment amount of the first spray water replenishment can also be 55 mL / kg, 60 mL / kg, 65 mL / kg, 70 mL / kg, 75 mL / kg, and any value within the range; the water replenishment amount of the second spray water replenishment can also be 220 mL / kg, 240 mL / kg, 260 mL / kg, 280 mL / kg, and any value within the range.

[0035] A second embodiment of the present application provides an amber crystal malt having both caramel and bread aromas, prepared by the method for preparing amber crystal malt having both caramel and bread aromas described in any of the above embodiments. This amber crystal malt has both high caramel and bread aromas. When used in beer brewing, sensory evaluation reveals a rich malt aroma, rich caramel and bread notes, and a clean, balanced body, free of foreign flavors such as burnt or mushy notes.

[0036] A third embodiment of the present application provides a beer brewed from the amber crystal malt having both caramel and bread aromas as described in any of the above embodiments. Sensory evaluation of the beer reveals a rich malt aroma, rich caramel and bread aromas, and a clean, balanced body without any foreign flavors such as burnt or mushy notes.

[0037] A fourth embodiment of the present application provides a beer, in which the malt used in the brewing process is prepared by the method for preparing amber crystal malt having both caramel aroma and bread aroma described in any of the above embodiments.

[0038] In order to more clearly and in detail introduce the amber crystal malt with caramel aroma and bread aroma, its preparation method and beer provided by the embodiments of the present application, the following description will be made with reference to specific examples.

[0039] Example 1

[0040] 1.1. Amber crystalline malt with caramel and bread aroma - Copeland

[0041] (1) Wheat selection: Copeland barley with a protein content of 12.3% was selected as the raw material. The barley grains were full and the germination rate was 99%;

[0042] (2) Raw material pretreatment: The barley is cleaned to remove impurities such as straw, bag ropes, wood blocks, nails, screws, metal wires, stones, miscellaneous wheat grains, and broken barley grains; and the barley is screened and graded to retain barley of uniform size with a length of 2.5 mm to 2.8 mm;

[0043] (3) Soaking barley: adding soaking water to the soaking tank, and then feeding the barley into the soaking tank, collecting a small part of the floating barley and impurities that float to the liquid surface through the collection port to complete the floating barley operation; after the floating barley is completed, the water quality is changed, and the barley is soaked at a water temperature of 15°C using a three-immersion and two-break low-temperature long-term soaking and water-breaking method, which 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%, and continuous ventilation and oxygen supply are used during the soaking process;

[0044] (4) Germination: The germination step is carried out in a ventilated germination equipment, the germination temperature is controlled at 12-18°C, and the germination time is 96 hours. Germination 0-12h is the first germination stage, and the germination temperature is 12°C; germination 12-72h is the second germination stage, and the germination temperature is 14°C; germination 72-96h is the third germination stage, and the germination temperature is 17°C. The first stirring time for germination is 12-20 hours after the end of feeding (within the second germination stage), and the wheat is turned over every 10-12 hours in the early germination period (approximately 0-12h) and the withering period (approximately 72-96h), and every 6-9 hours in the vigorous germination period (approximately 20-72h). At the end of germination, the average leaf bud length is 4 / 5-5 / 5 times the length of the wheat grain, accounting for 95% of the total malt, and the germination rate reaches 99%;

[0045] (5) Resting of green malt protein: Place the green malt in a roasting oven, and heat the oven at a constant speed of 1.5-2.0℃ / min. After the temperature reaches 50℃, perform a constant temperature protein rest for 40 minutes. At the end of the rest, the glycine content is 168mg / L and the serine content is 232mg / L. At the same time, control the exhaust volume of the roasting oven to 4.5m 3 / min, the moisture content of the green malt protein after resting is 15%. This process uses low temperature and high air volume to remove moisture from the green malt, promoting withering, reducing enzyme damage, and further promoting amino acid production. If the exhaust volume is low, the dehydration rate will inevitably be slow, causing the malt to easily develop a green taste and affecting the purity of the aroma.

[0046] (6) Green malt saccharification: After the protein rest is completed, the green malt is heated to 65°C at a constant rate of 4°C / h and saccharified at constant temperature for 60 minutes.

[0047] (7) Baking: After saccharification is completed, the speed of the baking oven is increased to 8 r / min, and the temperature is quickly raised to 100°C (within 20 minutes) and baked for 120 minutes. Then, the baking oven is heated to 145°C (within 25 minutes) and maintained at this baking temperature; the first water replenishment is performed, with a water replenishment amount of 50 mL / kg. After the temperature is heated to 140°C again, the second water replenishment is performed, with a water replenishment amount of 200 mL / kg.

[0048] (8) Derooting: The malt obtained in step (7) is immediately derooted to produce an amber crystal malt having both caramel and bread aromas.

[0049] The physicochemical indicators, agreed wort 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.

[0050] Table 1 Physical and chemical indicators of malt

[0051] Table 2 DMHF and 2-AP contents in wort

[0052] Table 3 Sensory evaluation results of wort

[0053] The purchased crystallized malt used for comparison in this embodiment is Caramel malt. The conventional malt preparation method employs a conventional malting process, specifically: the barley variety is Copeland, the malting process has a steeping degree of 42%, a germination time of 96 hours, a temperature of 15-16°C, and a drying process of 85°C for 3 hours, i.e., the Pilsner malt described in 1.2, 2.2, and 3.2 below.

[0054] 1.2. Beer with high caramel aroma and high bread aroma

[0055] 70% Pilsner malt was used as the brewing raw material, and 30% of the malted Copeland prepared in Example 1 was added. The physical and chemical indicators of the brewed wine met the GB / T 4927-2008 standard. The sensory evaluation results of national wine tasters are shown in Table 4.

[0056] Table 4 Sensory evaluation results of finished wine

[0057] Example 2

[0058] 2.1. Amber crystalline malt with caramel and bread aroma - Synergy

[0059] (1) Wheat selection: Select Synergy wheat with a protein content of 12.6% as the raw material, with full barley grains and a germination rate of 99%;

[0060] (2) Raw material pretreatment: The barley is cleaned to remove impurities such as straw, bag ropes, wood blocks, nails, screws, metal wires, stones, miscellaneous wheat grains, and broken barley grains; and the barley is screened and graded to retain barley of uniform size with a length of 2.5 mm to 2.8 mm;

[0061] (3) Soaking barley: adding soaking water to the soaking tank, and then feeding the barley into the soaking tank, collecting a small part of the floating barley and impurities that float to the liquid surface through the collection port to complete the floating barley operation; after the floating barley is completed, the water quality is changed, and the barley is soaked at a water temperature of 15°C using a three-immersion and two-break low-temperature long-term soaking and water-breaking method, which 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%, and continuous ventilation and oxygen supply are used during the soaking process;

[0062] (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 hours. Germination 0-12 hours is the first germination stage, and the germination temperature is 13°C; germination 12-72 hours is the second germination stage, and the germination temperature is 16°C; germination 72-96 hours is the third germination stage, and the germination temperature is 18°C. The first stirring time for germination is 12-20 hours after the end of feeding. The wheat is turned over every 10-12 hours in the early stage of germination and the withering period, and every 6-9 hours in the vigorous germination period. At the end of germination, the average leaf bud length is 4 / 5-5 / 5 times the length of the wheat grain, accounting for 95% of the total malt, and the germination rate reaches 99%;

[0063] (5) Resting of green malt protein: Place the green malt in a roasting oven, and heat the oven at a constant speed of 1.5-2.0℃ / min. After the temperature reaches 50℃, perform a constant temperature protein rest for 40 minutes. At the end of the rest, the glycine content is 154mg / L and the serine content is 228mg / L. At the same time, control the exhaust volume of the roasting oven to 4.7m 3 / min. The moisture content of green malt protein after resting is 12%. This process uses low temperature and high air volume to remove moisture from the green malt, promoting withering of the green malt, reducing enzyme damage, and further promoting amino acid production. If the exhaust volume is low, the dehydration speed will inevitably be slow, making the malt more likely to have a green taste and affecting the purity of the aroma.

[0064] (6) Green malt saccharification: After the protein rest is completed, the green malt is heated to 65°C at a constant rate of 4°C / h and saccharified at constant temperature for 60 minutes.

[0065] (7) Baking: After saccharification is completed, the speed of the baking oven is increased to 8 r / min, and the temperature is quickly raised to 95°C (within 20 minutes) and baked for 140 minutes. Then, the baking oven is heated to 143°C (within 25 minutes) and maintained at this baking temperature; the first water replenishment is performed, with a water replenishment amount of 80 mL / kg. After the temperature is heated to 140°C again, the second water replenishment is performed, with a water replenishment amount of 300 mL / kg.

[0066] (8) Derooting: The malt obtained in step (7) is immediately derooted to produce an amber crystal malt having both caramel and bread aromas.

[0067] The physicochemical indicators, agreed wort 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.

[0068] Table 5 Physical and chemical indicators of malt

[0069] Table 6 DMHF and 2-AP contents in wort

[0070] Table 7 Sensory evaluation results of wort

[0071] 2.2 Beer with high caramel aroma and high bread aroma

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

[0073] Table 8 Sensory evaluation results of finished wine

[0074] Example 3

[0075] 3.1. Amber crystalline malt with caramel and bread aroma - Metcalfe

[0076] (1) Wheat selection: Metcalfe with a protein content of 11.7% was selected as the raw material. The barley grains were full and the germination rate was 99%;

[0077] (2) Raw material pretreatment: The barley is cleaned to remove impurities such as straw, bag ropes, wood blocks, nails, screws, metal wires, stones, miscellaneous wheat grains, and broken barley grains; and the barley is screened and graded to retain barley of uniform size with a length of 2.5 mm to 2.8 mm;

[0078] (3) Soaking barley: adding soaking water to the soaking tank, and then feeding the barley into the soaking tank, collecting a small part of the floating barley and impurities that float to the liquid surface through the collection port to complete the floating barley operation; after the floating barley is completed, the water quality is changed, and the barley is soaked at a water temperature of 15°C using a three-immersion and two-break low-temperature long-term soaking and water-breaking method, which 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%, and continuous ventilation and oxygen supply are used during the soaking process;

[0079] (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 hours. Germination 0-12 hours is the first germination stage, and the germination temperature is 13°C; germination 12-72 hours is the second germination stage, and the germination temperature is 16°C; germination 72-96 hours is the third germination stage, and the germination temperature is 18°C. The first stirring time for germination is 12-20 hours after the end of feeding. The wheat is turned over every 10-12 hours in the early stage of germination and the withering period, and every 6-9 hours in the vigorous germination period. At the end of germination, the average leaf bud length is 4 / 5-5 / 5 times the length of the wheat grain, accounting for 95% of the total malt, and the germination rate reaches 99%;

[0080] (5) Resting of green malt protein: Place the green malt in a roasting oven, and heat the oven at a constant speed of 1.5-2.0℃ / min. After the temperature reaches 50℃, perform a constant temperature protein rest for 40 minutes. At the end of the rest, the glycine content is 164mg / L and the serine content is 216mg / L. At the same time, control the exhaust volume of the roasting oven to 4.7m 3 / min. The moisture content of green malt protein after resting is 14%. This process uses low temperature and high air volume to remove moisture from the green malt, promoting withering of the green malt, reducing enzyme damage, and further promoting amino acid production. If the exhaust volume is low, the dehydration speed will inevitably be slow, making the malt more likely to have a green taste and affecting the purity of the aroma.

[0081] (6) Green malt saccharification: After the protein rest is completed, the green malt is heated to 65°C at a constant rate of 4°C / h and saccharified at constant temperature for 60 minutes.

[0082] (7) Baking: After saccharification is completed, the speed of the baking oven is increased to 8 r / min, and the temperature is quickly raised to 98°C (within 20 minutes) and baked for 135 minutes. Then, the baking oven is heated to 140°C (within 25 minutes) and maintained at this baking temperature; the first water replenishment is performed, with a water replenishment amount of 60 mL / kg. After the temperature is heated to 140°C again, the second water replenishment is performed, with a water replenishment amount of 240 mL / kg.

[0083] (8) Derooting: The malt obtained in step (7) is immediately derooted to produce an amber crystal malt having both caramel and bread aromas.

[0084] The physicochemical indicators, agreed wort 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.

[0085] Table 9 Physical and chemical indicators of malt

[0086] Table 10 Wort DMHF, 2-AP content

[0087] Table 11 Sensory evaluation results of wort

[0088] 3.2. Beer with high caramel aroma and high bread aroma

[0089] 70% Pilsner malt was used as the brewing raw material, and 30% of the malted Metcalfe prepared in Example 3 was added. The physical and chemical indicators of the brewed wine met the GB / T 4927-2008 standard. The sensory evaluation results of national wine tasters are shown in Table 12.

[0090] Table 12 Sensory evaluation results of finished wine

[0091] Comparative Example 1

[0092] The same as Example 1, except that the germination process adopts a constant temperature germination process. Specifically:

[0093] 1. Amber crystalline malt with caramel and bread aroma - Copeland

[0094] (1) Wheat selection: Copeland barley with a protein content of 12.3% was selected as the raw material. The barley grains were full and the germination rate was 99%;

[0095] (2) Raw material pretreatment: The barley is cleaned to remove impurities such as straw, bag ropes, wood blocks, nails, screws, metal wires, stones, miscellaneous wheat grains, and broken barley grains; and the barley is screened and graded to retain barley of uniform size with a length of 2.5 mm to 2.8 mm;

[0096] (3) Soaking barley: adding soaking water to the soaking tank, and then feeding the barley into the soaking tank, collecting a small part of the floating barley and impurities that float to the liquid surface through the collection port to complete the floating barley operation; after the floating barley is completed, the water quality is changed, and the barley is soaked at a water temperature of 15°C using a three-immersion and two-break low-temperature long-term soaking and water-breaking method, which 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%, and continuous ventilation and oxygen supply are used during the soaking process;

[0097] (4) Germination: The germination process is carried out in a ventilated germination equipment, and the temperature is controlled at 16°C for 0-96 hours of germination. The first stirring time for germination is 12-20 hours after the end of feeding. The wheat is turned over every 10-12 hours during the early germination and withering periods, and every 6-9 hours during the active germination period. At the end of germination, the average leaf bud length is 4 / 5-5 / 5 times the length of the wheat kernel, accounting for 95% of the total malt, and the germination rate reaches 99%;

[0098] (5) Resting of green malt protein: Place the green malt in a roasting oven, and heat the oven at a constant speed of 1.5-2.0℃ / min. After the temperature reaches 50℃, perform a constant temperature protein rest for 40 minutes. At the end of the rest, the glycine content is 79mg / L and the serine content is 102mg / L. At the same time, control the exhaust volume of the roasting oven to 4.5m 3 / min. The moisture content of green malt protein after resting is 15%. This process uses low temperature and high air volume to remove moisture from the green malt, promoting withering of the green malt, reducing enzyme damage, and further promoting amino acid production. If the exhaust volume is low, the dehydration speed will inevitably be slow, making the malt more likely to have a green taste and affecting the purity of the aroma.

[0099] (6) Green malt saccharification: After the protein rest is completed, the green malt is heated to 65°C at a constant rate of 4°C / h and saccharified at constant temperature for 60 minutes.

[0100] (7) Baking: After saccharification is completed, the speed of the baking oven is increased to 8 r / min, and the temperature is quickly raised to 100°C (within 20 minutes) and baked for 120 minutes. Then, the baking oven is heated to 145°C (within 25 minutes) and maintained at this baking temperature; the first water replenishment is performed, with a water replenishment amount of 50 mL / kg. After the temperature is heated to 140°C again, the second water replenishment is performed, with a water replenishment amount of 200 mL / kg.

[0101] (8) Derooting: The malt obtained in step (7) is immediately derooted to obtain amber crystal malt.

[0102] Comparative Example 2

[0103] The same as Example 1, except that the germination process adopts the cooling germination process. Specifically:

[0104] 1. Amber crystalline malt with caramel and bread aroma - Copeland

[0105] (1) Wheat selection: Copeland barley with a protein content of 12.3% was selected as the raw material. The barley grains were full and the germination rate was 99%;

[0106] (2) Raw material pretreatment: The barley is cleaned to remove impurities such as straw, bag ropes, wood blocks, nails, screws, metal wires, stones, miscellaneous wheat grains, and broken barley grains; and the barley is screened and graded to retain barley of uniform size with a length of 2.5 mm to 2.8 mm;

[0107] (3) Soaking barley: adding soaking water to the soaking tank, and then feeding the barley into the soaking tank, collecting a small part of the floating barley and impurities that float to the liquid surface through the collection port to complete the floating barley operation; after the floating barley is completed, the water quality is changed, and the barley is soaked at a water temperature of 15°C using a three-immersion and two-break low-temperature long-term soaking and water-breaking method, which 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%, and continuous ventilation and oxygen supply are used during the soaking process;

[0108] (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 hours. Germination 0-12 hours is the first germination stage, and the germination temperature is 17°C; germination 12-72 hours is the second germination stage, and the germination temperature is 14°C; germination 72-96 hours is the third germination stage, and the germination temperature is 12°C. The first stirring time for germination is 12-20 hours after the end of feeding. The wheat is turned over every 10-12 hours in the early stage of germination and the withering period, and every 6-9 hours in the vigorous germination period. At the end of germination, the average leaf bud length is 4 / 5-5 / 5 times the length of the wheat grain, accounting for 95% of the total malt, and the germination rate reaches 99%;

[0109] (5) Resting of green malt protein: Place the green malt in a roasting oven, and heat the oven at a constant speed of 1.5-2.0℃ / min. After the temperature reaches 50℃, perform a constant temperature protein rest for 40 minutes. At the end of the rest, the glycine content is 88mg / L and the serine content is 117mg / L. At the same time, control the exhaust volume of the roasting oven to 4.5m 3 / min. The moisture content of green malt protein after resting is 15%. This process uses low temperature and high air volume to remove moisture from the green malt, promoting withering of the green malt, reducing enzyme damage, and further promoting amino acid production. If the exhaust volume is low, the dehydration speed will inevitably be slow, making the malt more likely to have a green taste and affecting the purity of the aroma.

[0110] (6) Green malt saccharification: After the protein rest is completed, the green malt is heated to 65°C at a constant rate of 4°C / h and saccharified at constant temperature for 60 minutes.

[0111] (7) Baking: After saccharification is completed, the speed of the baking oven is increased to 8 r / min, and the temperature is quickly raised to 100°C (within 20 minutes) and baked for 120 minutes. Then, the baking oven is heated to 145°C (within 25 minutes) and maintained at this baking temperature; the first water replenishment is performed, with a water replenishment amount of 50 mL / kg. After the temperature is heated to 140°C again, the second water replenishment is performed, with a water replenishment amount of 200 mL / kg.

[0112] (8) Derooting: The malt obtained in step (7) is immediately derooted to obtain amber crystal malt.

[0113] Comparative Example 3

[0114] Same as Example 1, except that water is not added during the baking process.

[0115] 1. Amber crystalline malt with caramel and bread aroma - Copeland

[0116] (1) Wheat selection: Copeland barley with a protein content of 12.3% was selected as the raw material. The barley grains were full and the germination rate was 99%;

[0117] (2) Raw material pretreatment: The barley is cleaned to remove impurities such as straw, bag ropes, wood blocks, nails, screws, metal wires, stones, miscellaneous wheat grains, and broken barley grains; and the barley is screened and graded to retain barley of uniform size with a length of 2.5 mm to 2.8 mm;

[0118] (3) Soaking barley: adding soaking water to the soaking tank, and then feeding the barley into the soaking tank, collecting a small part of the floating barley and impurities that float to the liquid surface through the collection port to complete the floating barley operation; after the floating barley is completed, the water quality is changed, and the barley is soaked at a water temperature of 15°C using a three-immersion and two-break low-temperature long-term soaking and water-breaking method, which 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%, and continuous ventilation and oxygen supply are used during the soaking process;

[0119] (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 hours. Germination 0-12h is the first germination stage, and the germination temperature is 12°C; germination 12-72h is the second germination stage, and the germination temperature is 14°C; germination 72-96h is the third germination stage, and the germination temperature is 17°C. The first stirring time for germination is 12-20 hours after the end of feeding. The wheat is turned over every 10-12 hours in the early germination and withering periods, and every 6-9 hours in the vigorous germination period. At the end of germination, the average leaf bud length is 4 / 5-5 / 5 times the length of the wheat grain, accounting for 95% of the total malt, and the germination rate reaches 99%;

[0120] (5) Resting of green malt protein: Place the green malt in a roasting oven, and heat the oven at a constant speed of 1.5-2.0℃ / min. After the temperature reaches 50℃, perform a constant temperature protein rest for 40 minutes. At the end of the rest, the glycine content is 164mg / L and the serine content is 228mg / L. At the same time, control the exhaust volume of the roasting oven to 4.5m 3 / min. The moisture content of green malt protein after resting is 15%. This process uses low temperature and high air volume to remove moisture from the green malt, promoting withering of the green malt, reducing enzyme damage, and further promoting amino acid production. If the exhaust volume is low, the dehydration speed will inevitably be slow, making the malt more likely to have a green taste and affecting the purity of the aroma.

[0121] (6) Green malt saccharification: After the protein rest is completed, the green malt is heated to 65°C at a constant rate of 4°C / h and saccharified at constant temperature for 60 minutes.

[0122] (7) Baking: After saccharification is completed, the speed of the baking oven is increased to 8 r / min, and the temperature is quickly raised (within 20 minutes) to 100°C and baked for 120 minutes. Then, the baking oven is heated up again (within 25 minutes) to 145°C.

[0123] (8) Derooting: The malt obtained in step (7) is immediately derooted to obtain amber crystal malt.

[0124] Performance Testing

[0125] The worts obtained in Examples 1-3 and Comparative Examples 1-3 were subjected to sensory evaluation and content detection. The results are shown in Table 13.

[0126] Table 13 Wort performance results obtained from Examples 1-3 and Comparative Examples 1-3

Claims

1. A method for preparing amber crystal malt with both caramel aroma and bread aroma, comprising a germination step and a roasting step, wherein: The germination step includes: a first germination stage of germination for 0-12 hours, a second germination stage of germination for 12-72 hours, and a third germination stage of germination for 72-96 hours; the germination temperature of the third germination stage is higher than the germination temperature of the second germination stage, and the germination temperature of the second germination stage is higher than the germination temperature of the first germination stage; The baking step includes: a low-temperature baking process and a high-temperature water-replenishing baking process; wherein, the high-temperature water-replenishing baking process includes: after the low-temperature baking process, raising the baking temperature to 140-145°C and performing a first spray water replenishment, after the first spray water replenishment, the baking temperature drops to below 140°C, and when the baking temperature rises to 140°C, a second spray water replenishment is performed; the water replenishment amount of the first spray water replenishment is less than the water replenishment amount of the second spray water replenishment.

2. The method for preparing amber crystal malt having both caramel aroma and bread aroma according to claim 1, wherein The germination temperature of the first germination stage is any value between 12-13°C; the germination temperature of the second germination stage is any value between 14-16°C; and the germination temperature of the third germination stage is any value between 17-18°C.

3. The method for preparing amber crystal malt having both caramel aroma and bread aroma according to claim 1 or 2, wherein: The water replenishment amount of the first spray replenishment is 50-80 mL / kg, and the water replenishment amount of the second spray replenishment is 200-300 mL / kg.

4. The method for preparing amber crystal malt having both caramel aroma and bread aroma according to claim 1 or 2, wherein: The low-temperature roasting process includes: in the initial stage of the low-temperature roasting process, controlling the moisture content of the green malt to any value between 12% and 15%, the low-temperature roasting temperature to 95-100° C., and the low-temperature roasting time to 120-140 minutes.

5. The method for preparing amber crystal malt having both caramel aroma and bread aroma according to claim 1, wherein The method further comprises 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%.

6. The method for preparing amber crystal malt having both caramel aroma and bread aroma according to claim 5, wherein: During the protein resting step, the exhaust volume is controlled to be no less than 4.5m 3 / min.

7. The method for preparing amber crystal malt having both caramel aroma and bread aroma according to claim 5 or 6, wherein: The resting temperature of the protein resting step is 50° C., and the resting time is 40 min.

8. The method for preparing amber crystal malt having both caramel aroma and bread aroma according to claim 1 or 2, wherein: The method further comprises a barley selection step before the germination step, wherein the barley selection step comprises selecting one of the following barleys as a malting raw material: Copeland barley, Synergy barley, and Metcalfe barley.

9. An amber crystal malt with caramel aroma and bread aroma, wherein: The amber crystalline malt having both caramel aroma and bread aroma is prepared by the preparation method of any one of claims 1 to 8.

10. A beer brewed from malt, wherein: The malt is prepared by the method for preparing amber crystal malt having both caramel aroma and bread aroma according to any one of claims 1 to 8.

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