CN116814348B

CN116814348B - A kind of turbid pear-flavored sour beer and preparation method thereof

Info

Publication number: CN116814348B
Application number: CN202310593976.3A
Authority: CN
Inventors: 刘成; 徐翠美; 邹曼; 张坤鹏; 张倩; 郭雪
Original assignee: Shandong Institute of Pomology
Current assignee: Shandong Institute of Pomology
Priority date: 2023-05-25
Filing date: 2023-05-25
Publication date: 2025-05-23
Anticipated expiration: 2043-05-25
Also published as: CN116814348A

Abstract

The invention discloses a turbid pear-flavored sour beer and a preparation method thereof, belonging to the technical field of beer. The pear-flavored sour beer is prepared by fermenting ale malt, wheat malt, autumn pear juice and caramel malt with lactic acid bacteria and yeast without adding exogenous saccharifying enzyme, and the original wort concentration is 8-10°P, the fermentation degree is 71-76%, the alcohol content is 3.6%-4.0%vol, the chroma is 9-12EBC, the turbidity is 90-120EBC, the bitterness value is 7-10IBU, and the pH value is less than 1. 3.6. The total organic acid content is ≥3.0mL/100mL. The taste is sweet and slightly sour, with a strong fruity aroma and a unique flavor. The produced wine is golden in color with a higher chroma. The wine has spicy and pear fruit aromas and a caramel malt aroma. At the same time, the present invention also provides a device for preparing acidified wort in the process of preparing sour beer, which can realize multiple functions such as boiling, cooling, precipitation, strain addition, carbon dioxide stirring and deoxygenation, primary fermentation of lactic acid bacteria, and anaerobic fermentation process, thereby improving production efficiency.

Description

Cloudy pear-flavored sour beer and preparation method thereof

Technical Field

The invention relates to the technical field of beer, in particular to cloudy pear-flavored sour beer and a preparation method thereof.

Background

Beer is one of the oldest beverage wines of humans, enjoying the reputation of "liquid bread". The development history of beer is exactly the development history from acid beer to beer and then to acid beer. According to the archaeological science report of the university of Stanford, the earliest beer appears in the Israel, riba tender, syrian and other areas before 11000 years before the first primordial, many pits are found on the surface of the mountain holes of the life of the Natufei at that time, some pits are used for breaking up wheat and barley, some pits are used for brewing ancient beer, the brewing method at that time is a natural fermentation mode, and the beer at that time is actually acid beer.

With the rise of the U.S. fine brewing in the 21 st century, acid beer has been touted by consumers due to the complicated characteristics of layering and differentiation. At present, acid beer mainly comprises Belgium acid beer, and the types of the acid beer include Frandes red Ail, guitzt and Lanbike, wherein the Belgium acid beer is mainly fermented by means of natural microbiota in a production area, has obvious regionality and cannot be copied. However, the acid beer in China still belongs to the starting stage, the technology for selecting the acid beer brewing strains, mixing fermentation and the like is not mature, and no acid beer product exists in the national standard GB/T4927 beer at present. Therefore, the cloudy fruit-flavored sour beer provided in China not only can solve the current situation that no cloudy sour beer exists in China, but also can enrich the taste and the variety of the sour beer in China through the addition of pear juice, and provides new taste experience for consumers.

The invention patent with publication number CN113061498B discloses a fresh acid beer and a preparation method thereof, wherein the fresh acid beer is prepared by fermenting pilsner malt and wheat malt with crystalline malt under the condition of not adding exogenous saccharifying enzyme. The fresh sour beer has fresh sour taste as main material, and the fresh sour beer has fresh sour taste, but has light taste, no fruit pulp, no fruit fragrance and low acceptance for some people who do not like sour, and can be added with the fruit fragrance to neutralize to produce turbid beer with layered taste, so that the taste can be accepted better.

In addition, the device used in the process of preparing and fermenting the prior acid beer can only perform fermentation operation, and has single function, so that the tank pouring is needed in the preparation process, the pollution probability to the fermentation tank is increased, and the preparation efficiency of the acid beer is reduced.

Disclosure of Invention

Aiming at the problems, the invention aims to provide the cloudy pear-flavored sour beer and the preparation method thereof, the pear-flavored sour beer is sweet in flavor and has layered sour flavor, rich in fruit flavor, unique in flavor and high in fermentation speed, and the matched boiling and fermentation integrated device for carrying out acidification fermentation on wort can realize a plurality of functions of boiling, cooling, precipitation, strain addition, carbon dioxide stirring, wort deoxygenation, lactobacillus primary fermentation, anaerobic fermentation process and the like, so that the operation steps are reduced, the production efficiency is improved, and the cost is saved.

In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:

The cloudy pear-flavored sour beer is characterized in that the cloudy pear-flavored sour beer is prepared by fermenting the raw materials of the elk malt, the wheat malt, the Qiu Yang pear juice and the burnt malt with the wild lactobacillus and the upper yeast under the condition of not adding exogenous saccharifying enzyme.

Further, the lactobacillus is prepared by natural fermentation of wild compound microorganism flora attached to the surface of malt.

Further, the addition of the elsholtzia accounts for 50% -60% of the total amount of the raw materials, the addition of the wheat malt accounts for 20% -30% of the total amount of the raw materials, the addition of the burnt malt accounts for 0% -5% of the total amount of the raw materials, and the addition of the Qiu Yang pear juice accounts for 10% -30% of the total amount of the wort.

Further, in the cloudy pear-flavored acid beer, the addition amount of the lactic acid bacteria is 0.8-1.5X10 ⁷ CFU/mL, and the addition amount of the above yeast is 0.4-0.6X10 ⁷ CFU/mL.

Further, the original wort concentration of the pear flavor acid beer is 8-10 degrees P, the fermentation degree is 71-76%, the alcohol content is 3.6-4.0% vol, the chromaticity is 9-12EBC, the turbidity is 90-120EBC, the bitter taste value is 7-10IBU, the pH is less than or equal to 3.6, and the total organic acid content is more than or equal to 3.0mL/100mL.

Further, the preparation method of the cloudy pear-flavored sour beer is characterized by comprising the following steps of,

S1, selecting the elk malt, the wheat malt, the Qiu Yang pear juice and the burnt malt as raw materials, mixing and crushing the elk malt, the wheat malt and the burnt malt, mixing the mixture with water according to a material-water ratio of 1:3-1:4, adding the Qiu Yang pear juice, and carrying out three-stage saccharification;

s2, after saccharification, filtering the mash at 76+/-1 ℃ to obtain clear wort;

s3, boiling the clarified wort for 5min to sterilize the wort, then circularly cooling to 40-44 ℃, and inoculating the sour wort prepared in advance;

s4, stirring carbon dioxide for 5-8min by taking the carbon dioxide as an adding power, and fermenting for 18-20 h at 40-44 ℃ in a sealed tank to obtain a primary fermentation liquid of the wort acidified by lactic acid bacteria;

S5, boiling wort fermentation liquor after the pH value is less than or equal to 3.8, adding hops, performing rotary precipitation after boiling, cooling to 18-20 ℃, charging oxygen into a fermentation tank, and controlling the dissolved oxygen of wort to 8-10mg/L.

S6, inoculating the above yeast, wherein the main fermentation temperature is 20 ℃ and the reduction temperature is 20 ℃, and when diacetyl is reduced to below 0.06mg/L, the temperature is reduced to 0-4 ℃, and the cold storage time is more than or equal to 7 days, so as to obtain beer fermentation liquor;

and S7, carrying out centrifugal treatment on the beer fermentation liquid, and carrying out instant sterilization and filling or filling pasteurization to obtain the cloudy pear-flavored sour beer.

Further, the temperature and time of the three-stage saccharification in the step S1 are specifically that the first-stage saccharification is carried out under the conditions of 43 ℃ and 40min of heat preservation, the second-stage saccharification is carried out under the conditions of 63 ℃ and 40min of heat preservation, and the third-stage saccharification is carried out under the conditions of 72 ℃ and 20min of heat preservation.

Further, the preparation method of the sour wort in the step S3 comprises the steps of mixing crushed malt with water according to a material-water ratio of 1:3-1:4, placing the mixture in a seed tank (3) for sealing, and then culturing the mixture in a incubator at 42-45 ℃ for 18-20 hours to obtain the sour wort after lactobacillus fermentation.

Further, the steps S3-S5 are carried out by adopting a boiling and fermentation integrated device, the boiling and fermentation integrated device comprises a wort boiling pot, a fermentation tank and a seed tank, the wort boiling pot is communicated with the fermentation tank through a wort circulating pipe, a circulating pump and a cooling thin plate are arranged on the wort circulating pipe, a circulating branch pipe is further connected between the wort circulating pump and the wort boiling pot, one end of the circulating branch pipe is communicated with the wort boiling pot, the other end of the circulating branch pipe is communicated with a part of the wort circulating pipe between the cooling thin plate and the fermentation tank, the seed tank is installed on the circulating branch pipe, and a seed tank thermometer, a seed tank pressure gauge and a CO ₂ are installed on the seed tank.

Furthermore, the wort kettle is of a double-layer jacket structure, a heating coil is arranged in the jacket, the top of the wort kettle is communicated with a water seal groove, a water seal plate is movably arranged in the water seal groove, the bottom of the water seal groove is communicated with a circle of water collecting groove, and the bottom of the water collecting groove is communicated with a drain pipe;

The wheat juice boiler comprises a wheat juice boiler body, wherein a wheat juice boiler body is arranged on the bottom surface of the wheat juice boiler body, the bottom surface of the wheat juice boiler body is of an inclined surface structure, a spray arm and a baffle are arranged on the bottom surface of the inner side of the wheat juice boiler body, a drain pipe is arranged at the bottom of the wheat juice boiler body in a communicated mode, a drain outlet corresponding to the drain pipe is located between the spray arm and the baffle, and a boiler thermometer is further arranged on the wheat juice boiler body.

Compared with the prior art, the invention has the advantages that the improvement is that,

1. According to the cloudy pear-flavored sour beer, the malt is adopted as the main raw material, and the wheat malt, qiu Yang pear juice and the scorched malt are added (the pears produced in China are mostly pearson malt), the Qiu Yang pear pulp is white, the meat is crisp, thin, free of slag and juice, extremely small in stone cells, and capable of achieving 13% of soluble solid content, sweet and slightly sour in taste, rich in fruit flavor, unique in flavor, golden in color of the produced wine, cloudy and cloudy, ornamental, and high in content of 4-vinyl guaiacol and isoamyl acetate in the wine produced by the above yeasts in the saccharification process, and the wine has spicy and fruit flavor and is provided with scorched malt.

2. The lactic acid bacteria in the invention adopts the wild compound microorganism flora attached to the malt epidermis for natural fermentation, the fermentation process of the lactic acid bacteria simultaneously acidizes wort, the wild compound microorganism flora attached to the malt epidermis contains multiple strains, the bacterial system is complex, and the flavor metabolin comprises butanedione, acetaldehyde and various amino acids, so that the taste layering sense of the produced wine is enhanced, and the taste is more mellow. Meanwhile, as the wild lactobacillus (the wild microbial flora attached to the malt epidermis) has high activity, strong tolerance and high fermentation speed, the wort can be fermented to pH less than or equal to 3.8 within 15-20 hours, and the time and the cost are saved.

3. The invention also discloses a preparation device which can realize a plurality of functions of boiling, cooling, precipitation, strain addition, carbon dioxide stirring and deoxidization, primary fermentation of lactobacillus, anaerobic fermentation process and the like, and compared with the existing saccharification boiling equipment, the device is additionally provided with a seed tank, a CO ₂ breather pipe, a unidirectional water sealing plate, a wort circulating pipe and a circulating branch pipe for cooling and refluxing, and can realize the functions of wort heating, boiling and sterilization, and lactobacillus fermentation in a wort boiling pot after wort cooling. The device has the advantages that carbon dioxide is used as an adding power and stirring and mixing tool of lactobacillus, an adding pump can be reduced, the effects of adding and mixing the strains and deoxidizing wort are achieved through stirring and washing of the carbon dioxide, one-way water sealing plates are opened during boiling, the lactobacillus is closed during primary fermentation, gas generated in the tank can be discharged from the valve, external air is isolated outside, the purpose of anaerobic fermentation is achieved, the original pot of fermentation broth is boiled and sterilized after fermentation, and the steps of pouring the fermentation broth and the probability of polluting other fermentation tanks during fermentation of the lactobacillus by using the fermentation tank (the lactobacillus is harmful bacteria for beer fermentation) are reduced. In general, the preparation device of the invention can realize multiple functions at the same time, reduce operation steps, improve production efficiency, save cost, reduce the probability of producing other beer polluted lactobacillus, improve the product quality of a brewery, and can be used for producing other fruit acid beer and secondary fermentation beer.

Drawings

FIG. 1 is a flow chart showing a process for producing cloudy pear-flavored acid beer according to the first embodiment of the present invention.

Fig. 2 is a schematic structural diagram of a preparation apparatus according to a second embodiment of the present invention.

FIG. 3 is a schematic view showing the internal structure of a wort copper according to a second embodiment of the present invention.

FIG. 4 is a top view showing the structure of the bottom surface of the wort copper of the preparation apparatus according to the second embodiment of the present invention.

Wherein, 1-wort boiling pot, 2-fermentation tank, 3-seed tank, 4-wort circulating pipe, 5-circulating pump, 6-cooling sheet, 7-circulating branch pipe, 8-seed tank thermometer, 9-seed tank manometer, 10-CO ₂ breather pipe, 11-heating coil, 12-water seal tank, 13-water seal plate, 14-water collection tank, 15-drain pipe, 16-sight glass, 17-spray arm, 18-baffle, 19-blow-down pipe, 20-boiling pot thermometer, 21-steam inlet pipe and 22-condensed water outlet pipe.

Detailed Description

In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is further described below with reference to the accompanying drawings and examples.

Embodiment one:

A cloudy pear-flavored sour beer is prepared from folium Artemisiae Argyi, semen Tritici Aestivi, qiu Yang pear juice and burnt malt by fermenting with lactobacillus and above yeast without adding exogenous saccharifying enzyme.

Specifically, the lactobacillus is prepared by natural fermentation of a wild compound microbial flora attached to the surface of the malt.

The recommended amount of the raw materials is 50% of the total amount of the raw materials, 25% of the total amount of the raw materials, 3% of the total amount of the raw materials and 22% of the total amount of the juice of Qiu Yang.

The preparation method of the cloudy pear-flavored sour beer comprises the following steps,

S1, selecting the elsholtzia, the wheat malt, the Qiu Yang pear juice and the burnt malt as raw materials, mixing and crushing the elsholtzia, the wheat malt and the burnt malt, mixing the materials with water according to a material-water ratio of 1:3-1:4, adding Qiu Yang pear juice, and carrying out three-stage saccharification, wherein the temperature and the time of the three-stage saccharification are specifically that the first-stage saccharification is carried out under the conditions of 43 ℃ and 40min of heat preservation, the second-stage saccharification is carried out under the conditions of 63 ℃ and 40min of heat preservation, and the third-stage saccharification is carried out under the conditions of 72 ℃ and 20min of heat preservation.

S3, boiling the clear wort for 5min, and then circularly cooling to 40-44 ℃;

The preparation method of the sour wheat juice (lactobacillus strain) comprises the steps of crushing malt, mixing the crushed malt with water according to a material-water ratio of 1:3-1:4, sealing the mixture in a seed tank, and culturing the mixture for 18-20h at 42-45 ℃ to obtain the sour wheat juice after lactobacillus fermentation. Mixing malt and water to produce mash, culturing wild compound microorganism flora attached to the surface of the malt in an incubator at 42-45 ℃ for 18-20 hours to form lactobacillus, acidifying wort to finally form sour wort, and adding the lactobacillus serving as a strain to a boiling pot to acidify wort lactic acid when the proliferation amount of the lactobacillus is about 0.8-1.5X10 ⁷ CFU/mL. Microbial microscopic examination and sensory evaluation are carried out before inoculation, and the non-lactic acid bacteria of the dominant bacterial group of microscopic examination are abandoned, and the sour wort with the abnormal flavor is evaluated.

S4, inoculating sour wort by taking carbon dioxide as an additive power, stirring for 5-8min by using carbon dioxide, and fermenting for 18-20h in a sealed tank to obtain lactobacillus-acidified wort fermentation liquor;

s5, boiling wort fermentation liquor after the pH value is less than or equal to 3.8, adding hops, performing rotary precipitation after boiling, cooling to 18-20 ℃, charging oxygen, controlling wort dissolved oxygen to 8-10mg/L, and transferring wort into a fermentation tank.

S6, inoculating the above yeasts (the adding amount of the above yeasts is controlled to be 0.4-0.6X10- ⁷ CFU/mL, the used above yeasts are Saccharomyces cerevisiae (LIDAKVEIKALEYEASTWLP 4052, purchased from America WhiteLabs company), transferring the above yeasts into a fermentation tank for fermentation, and cooling to 0-4 ℃ when diacetyl is reduced to below 0.06mg/L, and the cold storage time is more than or equal to 7 days to obtain beer fermentation liquor;

The pear-flavored sour beer finished product prepared by the method has golden appearance, and has high content of medium and low molecular proteins due to twice fermentation of proteins by lactic acid bacteria and saccharomycetes, cloudy turbidity of the wine, natural cloudiness, 120EBC turbidity after centrifugation, good foamability of the finished product, white and fine foam and lasting wall hanging.

The smelling fragrance has elegant lactic acid fragrance and yeast fragrance, and has fruit fragrance and spicy fragrance of bananas and Qiu Yang pears.

The pear juice contains rich organic acid and lactic acid generated by lactic acid bacteria, tastes sour and has a rich layering sense, is sour and stimulated, and has a fragrant and sweet flavor generated by wild lactic acid bacteria, and has a light banana and fruit flavor and full and mellow taste.

The detection index data are shown in table 1 below.

TABLE 1 Pear taste sour beer detection index data in the present invention

Index (I)	Product data
		Original wort concentration (° P)	10.1
Turbidity (EBC)	90-120
		True degree of fermentation (%)	72.5
PH	3.44
		Color competition (EBC)	10.57
Alcohol content (% vol)	3.9
		Diacetyl (mg/L)	0.05
Total acid (g/L)	4.32
		Lactic acid (g/L)	0.82
Bitter substance (IBU)	8.0
		Residual sugar (° P)	1.8

Embodiment two:

The second embodiment provides a wort acidification and fermentation integrated device for the steps S3-S5, and in particular, the wort acidification and fermentation integrated device structure is shown in the accompanying drawings 2-4, and comprises a wort boiling pot 1, a fermentation tank 2 and a seed tank 3, wherein the wort boiling pot 1 and the fermentation tank 2 are communicated through a wort circulating pipe 4, the wort circulating pipe 4 is provided with a circulating pump 5 and a cooling thin plate 6, the circulating pump 5 is close to one side of the wort boiling pot 1, the cooling thin plate 6 is close to one side of the fermentation tank 2, a circulating branch pipe 7 is further connected between the wort circulating pump 4 and the wort boiling pot 1, one end of the circulating branch pipe 7 is communicated with the wort boiling pot 1, the other end of the circulating branch pipe 7 is communicated with a part between the cooling thin plate 6 and the fermentation tank 2, the seed tank 3 is installed on the circulating branch pipe 7, a seed tank thermometer 8 and a seed tank pressure gauge ₂ and a CO gas circulating pipe 5324 are installed on the seed tank 3, and the seed tank 3 is used for measuring CO gas in the inside of the tool, and the tool CO gas is used for measuring the CO gas in the seed tank 4364.

The side wall of the wort copper 1 is of a double-layer jacket structure, a heating coil 11 is arranged in the jacket, the heating coil 11 can heat the interior of the wort copper 1, a water seal groove 12 is communicated with the top of the wort copper 1, a water seal plate 13 is movably arranged in the water seal groove 12, the water seal plate 13 can be opened and closed in the water seal groove 12, a circle of water collecting groove 14 is communicated with the bottom of the water seal groove 12, a drain pipe 15 is communicated with the bottom of the water collecting groove 14, when a large amount of steam is generated after wort in the wort copper 1 is boiled, the water seal plate 13 is opened, condensed water generated by steam condensation is collected in the water collecting groove 14 and discharged through the drain pipe 15, so that wort boiling can be guaranteed, a sight glass 16 is further arranged on the side wall of the wort copper 1 close to the top, and the sight glass 16 is used for observing the condition in the wort copper 1.

The bottom surface of wort copper 1 is inclined plane structure, and the inclination contained angle is at an optimum of 5, be equipped with spray arm 17 and baffle 18 on the inboard bottom surface of wort copper 1, the baffle 18 centers on wort copper 1 half circle, wort copper 1's bottom intercommunication is equipped with blow off pipe 19, the drain that blow off pipe 19 corresponds is located spray arm 17 with between the baffle 18 for the emission of thermal coagulum, the thermal coagulum that the wort in-process produced can deposit in wort copper 1's bottom, and baffle 18 can block the deposit and avoid entering into wort circulating pipe 4 together with the wort, and spray arm 17 can spray the washing to the deposit or the residue in the wort copper 1 after the wort is transported. A wort copper 20 is also mounted on the wort copper 1, said copper 20 being used for monitoring the wort temperature in the wort copper 1.

The working principle of the preparation device in the invention is that wort boiling in the step S3 is completed in the wort copper 1 for 5min so as to play a role in wort sterilization. The wort is then cooled to 40-44 by means of a circulation pump 5, a cooling lamella 6 and a circulation branch 7.

In the step S4, CO ₂ is introduced into the vent pipe 10 as power, the sour wort (lactobacillus strain) stored in the seed tank 3 is connected, and carbon dioxide stirring is carried out for 5-8min at the same time, so that the effects of uniformly mixing the strain and replacing oxygen in the wort are achieved, the water sealing plate 13 is closed, acidification of the wort is achieved, gas generated by fermentation can be discharged out of the boiling pot 1 through the water sealing plate 13, and primary anaerobic fermentation of the wort is completed.

In the step S5, after the pH value is less than or equal to 3.8, the wort fermentation liquor is boiled and sterilized in the boiling pot 1, so that the pollution probability can be reduced, the circulating pump 5 and the circulating branch pipe 7 are utilized for rotary precipitation, then the circulating pump 5 and the cooling thin plate 6 are utilized for secondary cooling to 18-20 ℃, oxygen is filled into the fermentation tank 2, and the secondary yeast fermentation of wort is realized in the step S6.

The foregoing has shown and described the basic principles, principal features and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and that the above embodiments and descriptions are merely illustrative of the principles of the present invention, and various changes and modifications may be made without departing from the spirit and scope of the invention, which is defined in the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. A method for preparing turbid pear-flavored sour beer, which is prepared by fermenting ale malt, wheat malt, autumn pear juice and caramel malt with lactic acid bacteria and yeast without adding exogenous saccharifying enzymes; characterized in that the preparation method comprises the following steps:

S1: Ale malt, wheat malt, autumn pear juice and caramel malt are selected as raw materials, the ale malt, wheat malt and caramel malt are mixed and crushed, mixed with water at a material-water ratio of 1:3-1:4, autumn pear juice is added, and three-stage saccharification is performed;

S2: After saccharification, the saccharified mash is filtered at 76±1°C to obtain clarified wort;

S3: Boil the clarified wort for 5 minutes to sterilize the wort, and then cool it to 40-44°C in a cycle;

S4: adding sour wort with carbon dioxide as the power source, stirring with carbon dioxide for 5-8 minutes, sealing the tank for fermentation for 18-20 hours, and obtaining wort fermentation liquid acidified by lactic acid bacteria;

The method for preparing the sour wort is as follows: grinding ale malt and mixing it with water at a material-water ratio of 1:3-1:4, placing it in a sealed seed tank (3), and then culturing it in an incubator at 42°C-45°C for 18-20 hours to obtain sour wort after lactic acid bacteria fermentation;

S5: When the pH is less than or equal to 3.8, the wort fermentation liquid is boiled and hops are added; after boiling, vortex precipitation is performed, the liquid is cooled to 18-20°C, oxygen is added, and the liquid is transferred to the fermentation tank, and the dissolved oxygen in the wort is controlled to be 8-10 mg/L;

S6: Add the yeast above, set the main fermentation temperature at 20°C and the reduction temperature at 20°C, wait until the diacetyl drops below 0.06 mg/L, cool to 0°C-4°C, and store in cold for ≥7 days to obtain beer fermentation liquid;

S7: centrifuging the beer fermentation liquid, and then instant-killing filling or filling pasteurizing to obtain a turbid pear-flavored sour beer.

2. The method for preparing a turbid pear-flavored sour beer according to claim 1, characterized in that the temperature and time of the three-stage saccharification in step S1 are specifically as follows: the first stage saccharification is carried out at 43° C. and kept warm for 40 minutes, the second stage saccharification is carried out at 63° C. and kept warm for 40 minutes, and the third stage saccharification is carried out at 72° C. and kept warm for 20 minutes.

3. The method for preparing a turbid pear-flavored sour beer according to claim 1, characterized in that: steps S3 to S5 are performed by a boiling and fermentation integrated device, the boiling and fermentation integrated device comprising a wort boiling pot (1), a fermentation tank (2) and a seed tank (3), the wort boiling pot (1) and the fermentation tank (2) are connected via a wort circulation pipe (4), the wort circulation pipe (4) is provided with a circulation pump (5) and a cooling thin plate (6), a circulation branch pipe (7) is further connected between the wort circulation pipe (4) and the wort boiling pot (1), one end of the circulation branch pipe (7) is connected to the wort boiling pot (1), and the other end of the circulation branch pipe (7) is connected to a portion of the wort circulation pipe (4) located between the cooling thin plate (6) and the fermentation tank (2), the seed tank (3) is mounted on the circulation branch pipe (7), and a seed tank thermometer (8), a seed tank pressure gauge (9) and a _CO2 ventilation pipe (10) are installed on the seed tank (3).

4. The method for preparing a turbid pear-flavored sour beer according to claim 3, characterized in that: the wort boiling pot (1) is a double-layer jacket structure, and a heating coil (11) is provided in the jacket; the top of the wort boiling pot (1) is connected to a water seal groove (12), a water seal plate (13) is movably provided in the water seal groove (12), the bottom of the water seal groove (12) is connected to a circle of water collecting groove (14), and the bottom of the water collecting groove (14) is connected to a drain pipe (15); the side wall of the wort boiling pot (1) near the top is also provided with a sight glass (16);

The bottom surface of the wort boiling pot (1) is an inclined structure, and a spray arm (17) and a baffle (18) are provided on the inner bottom surface of the wort boiling pot (1). A sewage pipe (19) is provided at the bottom of the wort boiling pot (1), and a sewage outlet corresponding to the sewage pipe (19) is located between the spray arm (17) and the baffle (18). A boiling pot thermometer (20) is also installed on the wort boiling pot (1).

5. The method for preparing turbid pear-flavored sour beer according to claim 1, wherein the lactic acid bacteria are wild composite microbial flora attached to the surface of malt.

6. The method for preparing a turbid pear-flavored sour beer according to claim 5, characterized in that the amount of ale malt added accounts for 50%-60% of the total amount of raw materials, the amount of wheat malt added accounts for 20%-30% of the total amount of raw materials, the amount of caramel malt added accounts for 3%-5% of the total amount of raw materials; and the amount of autumn pear juice added accounts for 10%-30% of the total amount of wort.

7 . The method for preparing turbid pear-flavored sour beer according to claim 6 , wherein the amount of the above yeast added to the turbid pear-flavored sour beer is 0.4-0.6×10 ⁷ CFU/mL.

8. The method for preparing a turbid pear-flavored sour beer according to claim 7, characterized in that the pear-flavored sour beer has an original wort concentration of 8-10°P, a fermentation degree of 71-76%, an alcohol content of 3.6%-4.0%vol, a chroma of 9-12EBC, a turbidity of 90-120EBC, a bitterness value of 7-10IBU, a pH value of ≤3.6, and a total organic acid content of ≥3.0mL/100mL.