Preparation method of selenium-rich craft beer

Abstract

The invention discloses a preparation method of selenium-enriched crafted beer, and aims to solve the problems that the existing beer is low in selenium content and the taste and flavor are influenced by selenium enrichment. The method comprises the following steps: firstly, selecting high-quality barley malt, humulus lupulus, yeast and water, and taking sodium selenite or selenium-enriched yeast as a selenium source; barley malt is soaked in a selenium-source-containing aqueous solution to be rich in selenium, and saccharification is performed after airing; mixing the selenium-enriched malt with other malt according to a ratio, saccharifying, filtering to obtain wort, boiling, and adding humulus lupulus in times; cooling the wort to a proper temperature, inoculating yeast for fermentation, performing low-temperature after-ripening after fermentation, and filtering; and finally, filling and pasteurizing. Through sensory evaluation, the beer disclosed by the invention is superior to conventional craft beer in appearance, aroma, taste and flavor coordination; main physicochemical indexes meet the national standard, and the selenium content is remarkably increased; bitter taste is appropriate and balanced with sweet taste. According to the method, the beer is rich in selenium on the basis of keeping good taste and flavor, and a craft beer product with a health-care function is provided for consumers.

Description

Technical Field

[0001] The present invention relates to the technical field of beer brewing, and particularly relates to a method for preparing selenium-rich craft beer. Background Art

[0002] Selenium is one of the essential trace elements for the human body and has various important physiological functions such as antioxidant, immune enhancement, and prevention of cardiovascular diseases. However, the human body cannot synthesize selenium by itself and mainly obtains it through food intake. With the improvement of people's health awareness, the demand for selenium-rich foods is increasing day by day.

[0003] Craft beer is loved by more and more consumers for its unique flavor, rich taste, and high-quality raw materials. However, most of the craft beers on the market currently do not contain selenium and cannot meet the needs of consumers for functional beers. Although there have been some studies on selenium-rich beers, there are problems such as unreasonable selenium addition methods, unstable selenium content, and influence on the taste and flavor of beer.

[0004] Therefore, it is of great significance to develop a method for preparing selenium-rich craft beer that can effectively enrich selenium without affecting the quality of beer. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for preparing selenium-rich craft beer, which makes the beer rich in selenium while maintaining good taste and flavor by reasonably adding selenium sources and controlling the brewing process.

[0006] To achieve the above purpose, the present invention is realized through the following technical solutions.

[0007] A method for preparing selenium-rich craft beer includes the following steps:

[0008] a) Raw material selection:

[0009] Select barley malt, hops, yeast strains, treated water, and sodium selenite or selenium-rich yeast as selenium sources;

[0010] b) Preparation of selenium-rich malt:

[0011] Soak the barley malt in an aqueous solution containing sodium selenite or selenium-rich yeast for 2 - 4 hours;

[0012] After soaking, dry the malt in a ventilated place, and then carry out saccharification with the saccharification temperature controlled at 62 - 68 °C for 1 - 1.5 hours;

[0013] c) Saccharification and filtration:

[0014] Mix the selenium-rich malt with other malts in a certain proportion and add an appropriate amount of water for saccharification;

[0015] After saccharification, the wort and spent grains are separated by filtration;

[0016] d) Boiling and adding hops:

[0017] The filtered wort is heated to boiling, and the boiling time is 60 - 90 minutes;

[0018] During the boiling process, hops are added in portions. The first addition is at the start of boiling, and the second addition is at 30 - 40 minutes of boiling;

[0019] e) Cooling and fermentation:

[0020] The boiled wort is rapidly cooled to 18 - 22 °C;

[0021] The cooled wort is inoculated with yeast and fermented for 7 - 14 days;

[0022] f) Maturation and filtration:

[0023] After fermentation, the beer is matured at low temperature for 1 - 2 weeks;

[0024] The matured beer is filtered by filtration method;

[0025] g) Bottling and sterilization:

[0026] The filtered beer is bottled into clean beer bottles;

[0027] The bottled beer is pasteurized at a temperature of 60 - 65 °C for 15 - 20 minutes.

[0028] Preferably, in the preparation step of the selenium - rich malt, the soaking ratio of barley malt to sodium selenite or selenium - rich yeast aqueous solution is that every 100 kg of barley malt is soaked in an aqueous solution containing 0.1 - 0.3 kg of sodium selenite or an equivalent amount of selenium - rich yeast.

[0029] Preferably, in the saccharification and filtration step, the mixing ratio of selenium - rich malt to other malts is that the selenium - rich malt accounts for 50% - 70%, and other malts account for 30% - 50%; the filtration method adopts filtration trough filtration or plate - and - frame filter filtration.

[0030] Preferably, in the boiling and adding hops step, the addition amount of hops is 0.1% - 0.2% of the wort amount, and the hops added for the first time account for 50% - 70% of the total addition amount.

[0031] Preferably, in the cooling and fermentation step, the cooling is carried out by a plate heat exchanger or a thin - plate cooler; the yeast inoculation amount is 0.03% - 0.07% of the wort amount.

[0032] Preferably, in the post-ripening and filtering steps, the post-ripening temperature is 2-6°C; and the filtering method adopts a diatomaceous earth filter or membrane filtration.

[0033] Preferably, in the filling and sterilization steps, the filling adopts isobaric filling technology; and the selenium content in the beer after pasteurization reaches 0.02-0.05 mg / L.

[0034] Beneficial effects of the present invention:

[0035] 1. Significant selenium-enriched effect: Through the preparation of selenium-enriched malt and the reasonable addition of selenium sources, the selenium content in beer reaches 0.02-0.05 mg / L, meeting the human body's demand for selenium intake.

[0036] 2. Good taste and flavor: Using high-quality raw materials and scientific brewing technology, the selenium-enriched process has little effect on the taste and flavor of beer. The beer has a strong malt aroma, moderate bitterness and rich foam.

[0037] 3. High safety: Strictly control the amount of selenium source added and the sanitary conditions during the brewing process to ensure the safety of beer and comply with relevant national standards. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0039] The scheme of the present invention is described in more detail and completely below.

[0040] 1. Technical solution

[0041] a) Raw material selection

[0042] Malt: Select high-quality barley malt with moderate protein content, which provides rich malt aroma and mellow taste for beer;

[0043] Hops: Choose hop varieties with typical aroma and bitterness, such as Cascade and Citra, to give the beer a unique flavor;

[0044] Yeast: Use yeast strains suitable for craft beer fermentation to ensure the fermentation process goes smoothly and produce good flavor substances;

[0045] Water: The water quality should meet the requirements of beer brewing and should be properly treated to remove impurities and odors;

[0046] Selenium source: Sodium selenite or selenium-enriched yeast is used as the selenium source. Sodium selenite is a commonly used inorganic selenium additive with low cost; selenium-enriched yeast is an organic selenium source with high bioavailability and little effect on the taste of beer.

[0047] b) Preparation of selenium-enriched malt

[0048] Soak barley malt in an aqueous solution containing sodium selenite or selenium-enriched yeast for 2 - 4 hours to allow the malt to fully absorb selenium.

[0049] After soaking, dry the malt in a well-ventilated place and then carry out saccharification. Control the saccharification temperature at 62 - 68 °C for 1 - 1.5 hours to convert the starch in the malt into fermentable sugars.

[0050] c) Saccharification and filtration

[0051] Mix the selenium-enriched malt with other malts in a certain proportion and add an appropriate amount of water for saccharification. During the saccharification process, by adjusting the temperature and time, make the enzymes in the malt fully play their roles and gradually convert starch into sugars such as maltose.

[0052] After saccharification, use a filtration method to separate the wort from the spent grains. Filtration trough filtration or plate filter press filtration can be used to ensure that the wort is clear and transparent.

[0053] d) Boiling and adding hops

[0054] Heat the filtered wort to boiling and boil for 60 - 90 minutes. During the boiling process, add hops in portions. Add them for the first time at the beginning of boiling, mainly providing bitterness. Add them for the second time 30 - 40 minutes after boiling to increase the aroma of the beer.

[0055] During the boiling process, proteins in the wort will coagulate and precipitate to form hot coagulants, which can be removed by sedimentation and filtration.

[0056] e) Cooling and fermentation

[0057] Quickly cool the boiled wort to the fermentation temperature, generally 18 - 22 °C. A plate heat exchanger or a thin plate cooler can be used for cooling.

[0058] Inoculate the cooled wort with yeast for fermentation. In the initial stage of fermentation, yeast multiplies in large numbers, producing carbon dioxide and alcohol. In the later stage of fermentation, yeast mainly carries out the conversion of metabolites to form flavor substances of the beer. The fermentation time depends on the yeast activity and the beer style, generally 7 - 14 days.

[0059] f) Maturation and filtration

[0060] After fermentation, carry out maturation treatment of the beer at low temperature for 1 - 2 weeks. During the maturation process, the flavor substances in the beer are further blended and stabilized, and the taste becomes more mellow.

[0061] The ripened beer is filtered using a diatomaceous earth filter or a membrane filter to remove suspended solids and microorganisms in the beer, making the beer clear and transparent.

[0062] g) Bottling and sterilization

[0063] The filtered beer is bottled into clean beer bottles using isobaric bottling technology to avoid the loss of carbon dioxide in the beer;

[0064] The bottled beer is pasteurized at a temperature of 60 - 65 °C for 15 - 20 minutes to kill the microorganisms in the beer and extend the shelf life.

[0065] II. Specific examples

[0066] (I) Example of preparing selenium - rich malt

[0067] Take 100 kg of barley malt, soak it in an aqueous solution containing 0.2 kg of sodium selenite for 3 hours, air - dry the soaked malt in a ventilated place, and then perform saccharification at a temperature of 65 °C for 1.2 hours.

[0068] (II) Example of brewing selenium - rich craft beer

[0069] Raw material ratio: 60% selenium - rich malt, 30% ordinary barley malt, 10% caramel malt; the total amount of hops is 0.15% of the wort volume; the yeast inoculation amount is 0.05% of the wort volume;

[0070] Saccharification and filtration: Mix the selenium - rich malt and other malts, add an appropriate amount of water, saccharify at 63 °C for 1 hour, then raise the temperature to 70 °C and hold for 30 minutes to complete saccharification, and filter using a filter tank to obtain clear wort;

[0071] Boiling and adding hops: Boil the wort for 75 minutes, add 60% of the hops at the beginning of boiling, and add the remaining 40% of the hops 40 minutes after boiling starts;

[0072] Cooling and fermentation: Cool the boiled wort to 20 °C using a plate heat exchanger, inoculate yeast for fermentation, and the fermentation time is 10 days;

[0073] Ripening and filtration: After fermentation, the beer is ripened at 4 °C for 1 week, and then filtered using a diatomaceous earth filter;

[0074] Bottling and sterilization: The filtered beer is bottled into beer bottles and pasteurized at a temperature of 62 °C for 18 minutes.

[0075] Through the above - mentioned specific implementation methods, selenium - rich craft beer with stable selenium content and good taste can be prepared.

[0076] (III) Comparative example: Preparation method of conventional craft beer

[0077] Raw material selection

[0078] Malt: High-quality barley malt is also selected, but it is not subjected to selenium enrichment treatment. The protein content and other indicators are similar to those of the malt used in the examples of the present invention to ensure the consistency of other basic components except selenium element;

[0079] Hops: Hops varieties with typical aroma and bitterness are selected, such as Cascade, Simcoe, etc., which are the same as those in the examples of the present invention to ensure the comparability of the flavors brought by the hops;

[0080] Yeast: Yeast strains suitable for craft beer fermentation are used, which are the same as those used in the examples of the present invention to exclude the influence of yeast on beer quality;

[0081] Water: The water quality meets the requirements of beer brewing. After the same water treatment process, impurities and peculiar smells are removed to ensure the same water quality conditions.

[0082] Brewing process

[0083] Mashing and filtration

[0084] The barley malt without selenium enrichment treatment is mixed with other malts (the ratio is the same as that in the examples of the present invention, that is, if the selenium-enriched malt accounts for 60%, the ordinary malt here is also mixed in the corresponding proportion, such as 60% of ordinary barley malt and 10% of caramel malt (if any)), and an appropriate amount of water is added for mashing; the mashing temperature and time are controlled in the same way as in the examples of the present invention. The mashing temperature is 62-68°C (taking the intermediate value of 65°C), and the time is 1-1.5 hours (taking 1.2 hours);

[0085] After mashing, the same filtration method as in the examples of the present invention (such as filtration tank filtration) is used to separate the wort and the spent grains.

[0086] Boiling and adding hops

[0087] The filtered wort is heated to boiling, and the boiling time is also 60-90 minutes (taking 75 minutes);

[0088] During the boiling process, hops are added in batches. The addition time and ratio are the same as those in the examples of the present invention, that is, 60% of the hops are added at the beginning of boiling, and the remaining 40% of the hops are added 40 minutes after boiling.

[0089] Cooling and fermentation

[0090] The boiled wort is cooled to the fermentation temperature of 18-22°C (taking 20°C) using the same cooling equipment as in the examples of the present invention (such as a plate heat exchanger);

[0091] The cooled wort is inoculated with yeast, and the yeast inoculation amount is the same as that in the examples of the present invention (such as 0.05% of the wort volume), and fermentation is carried out for 7 - 14 days (taking 10 days).

[0092] Aging and Filtration

[0093] After fermentation, the beer is aged at a low temperature, and the aging time and temperature are the same as those in the examples of the present invention, that is, 1 - 2 weeks (taking 1 week), and the temperature is 4°C;

[0094] The beer after aging is filtered using the same filtration method as in the examples of the present invention (such as filtration with a diatomaceous earth filter).

[0095] Filling and Sterilization

[0096] The filtered beer is filled into clean beer bottles using the same isobaric filling technology as in the examples of the present invention;

[0097] The filled beer is pasteurized, and the sterilization temperature and time are the same as those in the examples of the present invention, that is, the sterilization temperature is 60 - 65°C (taking 62°C), and the time is 15 - 20 minutes (taking 18 minutes).

[0098] III. Sensory Evaluation Panel and Sensory Evaluation Form

[0099] (I) Sensory Evaluation Panel

[0100] A sensory evaluation panel consisting of 20 people (10 males and 10 females) is selected. The members of the panel should have certain beer tasting experience or have received professional training and be able to accurately identify and describe the sensory characteristics of beer.

[0101] (II) Sensory Evaluation Form

[0102]

[0103]

[0104] Evaluation Instructions: The sensory evaluation panel blindly evaluates and scores the beer of the examples and comparative examples of the present invention according to the above evaluation criteria, and takes the average score as the final score. It can be seen from the evaluation results that the examples of the present invention are superior to the comparative examples in terms of appearance, aroma, taste, and flavor coordination.

[0105] IV. Main Physicochemical Index Tests

[0106] (I) Test Method

[0107] The main physicochemical indexes of the liquor of the examples and comparative examples of the present invention are tested according to the methods specified in the national standard GB / T 4927 - 2008 "Beer".

[0108] (2) Main physical and chemical index test form

[0109]

[0110]

[0111] Conclusion: The main physical and chemical indexes of the examples and comparative examples of the present invention, such as original wort concentration, alcohol content, true fermentation degree, colority, pH value, total acid and carbon dioxide content, all meet the national standard requirements. However, the selenium content in the examples of the present invention is significantly higher than that in the comparative examples, achieving the purpose of selenium enrichment.

[0112] V. Determination of Bitterness Substances (BU)

[0113] (1) Determination method

[0114] The international bitterness unit (IBU) determination method is adopted. The content of iso-α-acids in beer is measured using an ultraviolet spectrophotometer, and the bitterness substance (BU) value is calculated.

[0115] (2) Bitterness substance (BU) determination form

[0116]

[0117] Conclusion: The bitterness substance (BU) value of the examples of the present invention is slightly higher than that of the comparative examples, but still within the appropriate range. Appropriate bitterness can increase the taste level and flavor complexity of beer, and at the same time balance with the sweetness of malt, making the beer taste more coordinated.

[0118] VI. Comprehensive conclusion

[0119] Through sensory evaluation, main physical and chemical index test and bitterness substance (BU) determination, the following conclusions can be drawn:

[0120] Sensory quality: The selenium-enriched craft beer of the examples of the present invention is superior to the comparative examples in terms of appearance, aroma, taste and flavor coordination. It has a strong malt aroma, a fresh hop aroma and a coordinated taste, and is more popular among consumers.

[0121] Physical and chemical indexes: The main physical and chemical indexes of the examples and comparative examples of the present invention all meet the national standard requirements. However, the present invention has successfully achieved selenium enrichment in the examples, and the selenium content is significantly higher than that in the comparative examples, providing a beer product with health care functions for consumers.

[0122] Bitterness substances: The bitterness substance (BU) value of the examples of the present invention is appropriate, balancing with the malt sweetness, making the beer taste more rich and coordinated.

[0123] In summary, the preparation method of the selenium-rich craft beer provided by the present invention can effectively increase the selenium content of the beer, while maintaining good sensory qualities and physical and chemical indexes, and has remarkable innovation and practicability.

[0124] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0125] The above are only the preferred embodiments of the present invention patent, and are not intended to limit the present invention patent. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention patent shall be included in the protection scope of the present invention patent.

Claims

1. A method for preparing selenium-enriched craft beer, characterized in that: The following steps are involved: a) Raw material selection: Barley malt, hops, yeast strains, treated water, and sodium selenite or selenium-enriched yeast are used as selenium sources; b) Preparation of selenium-enriched malt: Soaking barley malt in an aqueous solution containing sodium selenite or selenium-enriched yeast for 2-4 hours; The soaked malt is dried in a ventilated place and then saccharified. The saccharification temperature is controlled at 62-68°C and the time is 1-1.5 hours. c) Saccharification and filtration: Mix the selenium-rich malt with other malts in a certain proportion and add an appropriate amount of water for saccharification; After saccharification, the wort and spent grains are separated by filtration; d) Boiling and adding hops: Heat the filtered wort to boiling for 60-90 minutes; During the boiling process, add hops in batches, the first time at the beginning of the boil, and the second time after 30-40 minutes of boiling; e) Cooling and fermentation: After boiling, the wort is quickly cooled to 18-22℃; The cooled wort is added with yeast for fermentation, and the fermentation time is 7-14 days; f) Post-ripening and filtration: After fermentation, the beer is aged at low temperature for 1-2 weeks. The beer after maturation is filtered by filtration; g) Filling and sterilization: Fill the filtered beer into clean beer bottles; The beer is pasteurized after filling at a temperature of 60-65°C for 15-20 minutes.

2. The method for preparing selenium-enriched craft beer according to claim 1, characterized in that: In the selenium-enriched malt preparation step, the soaking ratio of barley malt and sodium selenite or selenium-enriched yeast aqueous solution is that every 100 kg of barley malt is soaked in an aqueous solution containing 0.1-0.3 kg of sodium selenite or an equal amount of selenium-enriched yeast.

3. The method for preparing selenium-enriched craft beer according to claim 1, characterized in that: In the saccharification and filtration steps, the mixing ratio of selenium-rich malt and other malts is 50%-70% of selenium-rich malt and 30%-50% of other malts; the filtration method adopts filter tank filtration or filter press filtration.

4. The method for preparing selenium-enriched craft beer according to claim 1, characterized in that: In the boiling and hops adding steps, the amount of hops added is 0.1%-0.2% of the amount of wort, and the hops added for the first time account for 50%-70% of the total amount added.

5. The method for preparing selenium-enriched craft beer according to claim 1, characterized in that: In the cooling and fermentation steps, cooling adopts a plate heat exchanger or a thin plate cooler; the yeast inoculation amount is 0.03%-0.07% of the wort amount.

6. The method for preparing selenium-enriched craft beer according to claim 1, characterized in that: In the post-ripening and filtering steps, the post-ripening temperature is 2-6° C.; the filtering method adopts a diatomaceous earth filter or membrane filtration.

7. The method for preparing selenium-enriched craft beer according to claim 1, characterized in that: In the filling and sterilization steps, the filling adopts isobaric filling technology; and the selenium content in the beer reaches 0.02-0.05 mg / L after pasteurization.

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