阅读说明：本技术 深色小麦啤酒及其制备方法 (Dark wheat beer and preparation method thereof ) 是由 董建军 徐楠 尹花 胡孝丛 常宗明 尚艳丽 张文铎 邢磊 刘晓琳 黄树丽 钱中华 于 2020-12-31 设计创作，主要内容包括：本发明提出一种深色小麦啤酒及其制备方法,属于啤酒酿造技术领域,能够解决目前国内深色小麦啤酒4-VG含量低、丁香风味弱的技术问题。该款深色小麦啤酒采用皮尔森麦芽、小麦芽搭配类黑素麦芽、结晶麦芽和巧克力麦芽为原料,通过上面发酵法制得,所述啤酒的的原麦汁浓度为10-12°P,酒精度为4.0-5.5％vol,色度为50-70EBC,苦味质为10-15EBC,且所述啤酒中4-VG含量为2.0-3.0mg/L,麦芽香气物质2-乙酰吡咯含量≥150μg/L。本发明能够应用于深色小麦啤酒的生产中。(The invention provides dark wheat beer and a preparation method thereof, belongs to the technical field of beer brewing, and can solve the technical problems of low 4-VG content and weak clove flavor of the current domestic dark wheat beer. The dark wheat beer is prepared by adopting Pearson malt, wheat malt matched with melanoid malt, crystalline malt and chocolate malt as raw materials through the fermentation method, wherein the original wort concentration of the beer is 10-12 DEG P, the alcoholic strength is 4.0-5.5% vol, the chroma is 50-70EBC, the bitter substance is 10-15EBC, the content of 4-VG in the beer is 2.0-3.0mg/L, and the content of 2-acetylpyrrole in malt fragrance substances is more than or equal to 150 mu g/L. The invention can be applied to the production of dark wheat beer.)

1. Dark wheat beer is characterized in that the beer is prepared by adopting Pearson malt, wheat malt matched with melanoid malt, crystalline malt and chocolate malt as raw materials through the fermentation method, the concentration of original wort of the beer is 10-12 DEG P, the alcoholic strength is 4.0-5.5% vol, the chroma is 50-70EBC, the bitter taste quality is 10-15EBC, the content of 4-VG in the beer is 2.0-3.0mg/L, and the content of malt fragrance substance 2-acetylpyrrole is more than or equal to 150 mu g/L.

2. The dark wheat beer in accordance with claim 1 wherein the alcohol ester ratio of said beer is 4.0-5.0 and the 2-acetylpyrrole content of said malt aroma in said beer is 150-200 μ g/L.

3. The dark wheat beer according to claim 1 wherein the starting material comprises 35-45% pilsner malt, 40-50% wheat malt, 8-15% melanoid malt, 4-8% crystalline malt and 2-6% chocolate malt.

4. The dark wheat beer as claimed in claim 3, wherein the Pearson malt color is 3-5EBC, the wheat malt color is 4-6EBC, the melanoid malt color is 40-70EBC, the crystalline malt color is 200-400EBC, and the chocolate malt color is 500-800 EBC.

5. A method of producing dark wheat beer according to any one of claims 1 to 4 comprising the steps of:

the method comprises the following steps of taking water and malt as main raw materials, wherein the malt is selected from Pearson malt, wheat malt matched with melanoidin malt, crystalline malt and chocolate malt, crushing the malt, and mixing the crushed malt and the water in a ratio of 1: (3.5-4.0) mixing, and carrying out four-stage saccharification at the temperature of 32-73 ℃;

after saccharification, carrying out wort filtration on the saccharified mash at 75-78 ℃ to obtain clear wort, boiling, adding hops or hop products in the boiling process in several times, carrying out rotary precipitation after boiling, cooling to 16-22 ℃, and simultaneously, oxygenating and inoculating the above fermentation yeast for fermentation to obtain beer fermentation liquor;

and filtering the beer fermentation liquor, filling, sterilizing and packaging finished products to obtain the dark wheat beer.

6. The method of claim 5, wherein the four-stage saccharification comprises: performing first stage saccharification at 32-40 deg.C for 15-30min, performing second stage saccharification at 45-55 deg.C for 15-30min, performing third stage saccharification at 62-68 deg.C for 20-60min, and performing fourth stage saccharification at 70-73 deg.C for 10-30min, wherein no exogenous enzyme preparation is added during the whole saccharification process.

7. The method of claim 5, wherein the boiling time is 60-70min and the boiling evaporation rate is 7-8%.

8. The method of claim 5, wherein the fractional addition of hops or hop preparations during the boiling process comprises:

adding flos Lupuli or flos Lupuli product at the beginning of boiling and 30-35min, respectively, with the addition amount of 0.5-1.0kg/kL and 1.0-2.0 kg/kL.

9. The method of claim 5, wherein the hop or hop product is selected from at least one of Qingdao flowers, guding, Barbady, Fager and Magnus.

10. The method for preparing dark wheat beer according to claim 5, wherein the oxygenating and inoculating the above fermenting yeast for fermentation specifically comprises:

oxygenating the rotary precipitated and cooled wort, controlling the dissolved oxygen of the wort to 7-10mg/L, inoculating the top fermentation yeast, and controlling the yeast in the full tank to 8.0-12.0 x 10⁶The fermentation temperature is 16-22 ℃, the fermentation time is 8-13 days, the cold storage temperature is-2-0 ℃, and the cold storage time is 7-15 days;

the above fermentation yeast is at least one selected from Weiss yeast, WB-06 yeast or Munich traditional wheat yeast.

Technical Field

The invention belongs to the technical field of beer brewing, and particularly relates to dark wheat beer and a preparation method thereof.

Background

In recent years, with social development and continuous improvement of living standard of people, the special beer is more and more popular with people, consumers do not meet the requirement of drinking the following fermented light-colored Lag beer any more, higher requirements are provided for the taste, flavor and type of the beer, and the special beer is bound to become the inevitable development trend of the beer industry.

The styles and types of beer are various, and the color is one of the important criteria for determining the styles and types of beer. At present, light-colored wheat beer, namely 'white beer' with a characteristic of a clove flavor on the market is rapidly increased, but dark-colored wheat beer is rarely seen on the market, and the dark-colored wheat beer has low content of 4-vinyl guaiacol (4-VG) and weak clove flavor, because the dark-colored wheat beer uses more dark-colored malt, the content of a 4-VG precursor is reduced. Therefore, it is an important subject to be studied by those skilled in the art how to improve wheat beer to have both clove flavor and toasted flavor, and solve the technical problems of low 4-VG content and weak clove flavor of dark wheat beer.

Disclosure of Invention

The invention provides dark wheat beer and a preparation method thereof, the dark wheat beer has obvious clove taste, simultaneously has malt scorch aroma and baking aroma, and solves the technical problems of low 4-VG content and weak clove flavor of the current domestic dark wheat beer.

In order to achieve the purpose, the invention adopts the technical scheme that:

dark wheat beer which is prepared by adopting Pearson malt, wheat malt matched with melanoid malt, crystalline malt and chocolate malt as raw materials through the fermentation method, wherein the original wort concentration of the beer is 10-12 DEG P, the alcoholic strength is 4.0-5.5% vol, the chroma is 50-70EBC, the bitter substance is 10-15EBC, the content of 4-VG in the beer is 2.0-3.0mg/L, and the content of malt fragrance substance 2-acetylpyrrole is more than or equal to 150 mu g/L.

Preferably, the alcohol ester ratio of the beer is 4.0-5.0, and the content of the malt aroma substance 2-acetyl pyrrole in the beer is 150-200 mu g/L.

Preferably, the raw material comprises 35-45% of Pearson malt, 40-50% of wheat malt, 8-15% of melanoid malt, 4-8% of crystalline malt and 2-6% of chocolate malt.

Preferably, the Pearson malt color is 3-5EBC, the wheat malt color is 4-6EBC, the melanoid malt color is 40-70EBC, the crystalline malt color is 200-400EBC, and the chocolate malt color is 500-800 EBC.

The invention also provides a preparation method of the dark wheat beer by using any one of the preferable technical schemes, which comprises the following steps:

the method comprises the following steps of taking water and malt as main raw materials, wherein the malt is selected from Pearson malt, wheat malt matched with melanoidin malt, crystalline malt and chocolate malt, crushing the malt, and mixing the crushed malt and the water in a ratio of 1: (3.5-4.0) mixing, and carrying out four-stage saccharification at the temperature of 32-73 ℃;

after saccharification, carrying out wort filtration on the saccharified mash at 75-78 ℃ to obtain clear wort, boiling, adding hops or hop products in the boiling process in several times, carrying out rotary precipitation after boiling, cooling to 16-22 ℃, and simultaneously, oxygenating and inoculating the above fermentation yeast for fermentation to obtain beer fermentation liquor;

and filtering the beer fermentation liquor, filling, sterilizing and packaging finished products to obtain the dark wheat beer.

Preferably, the four-stage saccharification comprises: performing first stage saccharification at 32-40 deg.C for 15-30min, performing second stage saccharification at 45-55 deg.C for 15-30min, performing third stage saccharification at 62-68 deg.C for 20-60min, and performing fourth stage saccharification at 70-73 deg.C for 10-30min, wherein no exogenous enzyme preparation is added during the whole saccharification process.

Preferably, the boiling time is 60-70min, and the boiling evaporation rate is 7-8%.

Preferably, the step of adding the hops or the hop products in the boiling process comprises:

adding flos Lupuli or flos Lupuli product at the beginning of boiling and 30-35min, respectively, with the addition amount of 0.5-1.0kg/kL and 1.0-2.0 kg/kL.

Preferably, the hop or hop product is selected from at least one of the group consisting of Qingdao, guding, Barceli, Fager and Magnus.

Preferably, the oxygenating and inoculating the above fermentation yeast to perform fermentation specifically comprises:

oxygenating the rotary precipitated and cooled wort, controlling the dissolved oxygen of the wort to 7-10mg/L, inoculating the top fermentation yeast, and controlling the yeast in the full tank to 8.0-12.0 x 10⁶The fermentation temperature is 16-22 ℃, the fermentation time is 8-13 days, the cold storage temperature is-2-0 ℃, and the cold storage time is 7-15 days;

the above fermentation yeast is at least one selected from Weiss yeast, WB-06 yeast or Munich traditional wheat yeast.

Compared with the prior art, the invention has the advantages and positive effects that:

1. the invention provides dark wheat beer and a preparation method thereof, the beer is prepared by adopting Pearson malt, wheat malt matched with melanoidin malt, crystallized malt and chocolate malt through the fermentation method, the obtained beer has the flavor of clove and baking fragrance, is soft in taste, not bitter after baking, light and cool and easy to drink, and the technical problems of low 4-VG content and weak flavor of clove of the current domestic dark wheat beer are solved;

2. the invention provides dark wheat beer and a preparation method thereof, the dark wheat beer is brewed by adopting 100 percent of malt, no enzyme preparation is added in the brewing process, and the dark wheat beer with obvious clove flavor, malt scorched aroma and roasted aroma is finally prepared by reasonably matching the use amount of different malt and adopting proper saccharification and fermentation processes.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The embodiment of the invention provides dark wheat beer, which is prepared by adopting Pearson malt, wheat malt matched melanoid malt, crystalline malt and chocolate malt as raw materials through the fermentation method, wherein the original wort concentration of the beer is 10-12 DEG P, the alcoholic strength is 4.0-5.5% vol, the chroma is 50-70EBC, the bitter taste quality is 10-15EBC, the content of 4-VG in the beer is 2.0-3.0mg/L, and the content of malt fragrance substances, namely 2-acetylpyrrole, is more than or equal to 150 mu g/L.

In a preferred embodiment, the alcohol ester ratio of the beer is 4.0-5.0, and the content of the malt aroma 2-acetylpyrrole in the beer is 150-200 mu g/L.

The dark wheat beer provided by the embodiment is made of whole wheat, and the selected malt mainly comprises Pearson malt, wheat malt matched melanoid malt, crystalline malt and chocolate malt as raw materials, wherein the Pearson malt accounts for 35-45% of the content of the selected malt, the wheat malt accounts for 40-50% of the content of the raw materials, the melanoid malt accounts for 8-15% of the content of the raw materials, the crystalline malt accounts for 4-8% of the content of the raw materials, and the chocolate malt accounts for 2-6% of the content of the raw materials; in addition, the beer formula does not need rice, corn and other auxiliary materials, an exogenous enzyme preparation is not added, the beer prepared by combining the specifically limited raw wort concentration, alcoholic strength, bitter taste quality, chroma, 4-VG content and malt aroma substance 2-acetylpyrrole content of the beer has the clove flavor, has the baking flavor, is soft in taste, not bitter after taste, light and comfortable and easy to drink, and solves the technical problems that the current dark wheat beer is low in 4-VG content and weak in clove flavor.

It is understood that the above examples are all limited to the relevant parameters for obtaining the beer, and further limit the raw materials for preparing the beer, such as in a preferred embodiment, the Pearson malt color is 3-5EBC, the wheat malt color is 4-6EBC, the melanoid malt color is 40-70EBC, the crystalline malt color is 200-400EBC, and the chocolate malt color is 500-800 EBC.

Further, the reason why the present invention selects various kinds of malt having coloring effect as raw materials is that: the different shades of colored malt provide different aromas, the melanoid malt provides a burnt and roasted aroma, the lower proportion of crystallized malt provides a caramel aroma, the lower proportion of high shade chocolate malt provides a deep roasted aroma, while the reduction in beer to target shade reduces the proportion of dark malt used to ensure that a large amount of light malt is used.

In addition, in order to solve the technical problem that the content of 4-VG in dark wheat beer is low, the malt formula and the using amount thereof are clearly limited, because: free ferulic acid in wort is a precursor of 4-VG, the free ferulic acid is converted by yeast to generate 4-VG in the fermentation process, but most ferulic acid exists in a bound state in malt, and can be released under the action of ferulic acid decarboxylase in the saccharification process, so that the higher the activity of ferulic acid decarboxylase in the malt, the more free ferulic acid is generated. The darker the malt color is, the higher the temperature in the roasting process is, the more the damage to the enzyme activity in the malt is, and the lower the enzyme activity in the dark malt, so the use of the dark malt in high proportion can reduce the production of free ferulic acid, more than 75% of the malt used in the application is light malt (Pierson malt and wheat malt) and 15% of melanoid malt with lower color, and the use of dark malt with the color not more than 10% ensures the activity of ferulic acid decarboxylase in the saccharification process, ensures the content of ferulic acid in the wort, and further ensures the content of 4-VG in the dark wheat beer.

The invention also provides a preparation method of dark wheat beer by using any one of the preferred embodiments, which comprises the following steps:

s1, taking water and malt as main raw materials, wherein the malt is selected from Pearson malt, wheat malt matched with melanoidin malt, crystalline malt and chocolate malt, crushing the malt, and then mixing the crushed malt and the raw materials according to a ratio of water to material of 1: (3.5-4.0) mixing, and carrying out four-stage saccharification at the temperature of 32-73 ℃;

in this step, the saccharification process is optimized as a four-stage saccharification, wherein the first stage saccharification batch temperature is lower, which is limited to 32-40 ℃ because: in a lower temperature range, the hydrolysis of the ferulic acid is facilitated, and more 4-VG precursor-free ferulic acid can be produced.

S2, after saccharification, filtering the saccharified mash at 75-78 ℃ to obtain clear wort, boiling, adding hops or hop products in the boiling process in a plurality of times, carrying out rotary precipitation after boiling, cooling to 16-22 ℃, and simultaneously, oxygenating and inoculating the fermented yeast to ferment to obtain beer fermentation liquor;

s3, filtering the beer fermentation liquor, filling, sterilizing and packaging finished products to obtain the dark wheat beer.

In a preferred embodiment, the four-stage saccharification comprises: the four-stage saccharification comprises: performing first stage saccharification at 32-40 deg.C for 15-30min, performing second stage saccharification at 45-55 deg.C for 15-30min, performing third stage saccharification at 62-68 deg.C for 20-60min, and performing fourth stage saccharification at 70-73 deg.C for 10-30min, wherein no exogenous enzyme preparation is added during the whole saccharification process.

In a preferred embodiment, the boiling time is 60-70min, and the boiling evaporation rate is 7-8%.

In the above preferred embodiment, the boiling time can be selected from 60min, 65 min and 70min or any value selected from the above range according to actual needs falls within the protection scope of the present invention, and the boiling evaporation rate can be selected from 7%, 7.5% and 8% or any value selected from the above range according to actual needs falls within the protection scope of the present invention.

In a preferred embodiment, the fractionated addition of the hops or hop preparation during the boiling process comprises:

adding flos Lupuli or flos Lupuli product at the beginning of boiling and 30-35min, respectively, with the addition amount of 0.5-1.0kg/kL and 1.0-2.0 kg/kL.

In a preferred embodiment, the hop or hop product is selected from at least one of the group consisting of Qingdao, Gudin, Barbady, Fager and Magnum.

In a preferred embodiment, the oxygenating and inoculating the above fermenting yeast to ferment specifically comprises:

oxygenating the rotary precipitated and cooled wort, controlling the dissolved oxygen of the wort to 7-10mg/L, inoculating the top fermentation yeast, and controlling the yeast in the full tank to 8.0-12.0 x 10⁶The fermentation temperature is 16-22 ℃, the fermentation time is 8-13 days, the cold storage temperature is-2-0 ℃, and the cold storage time is 7-15 days;

the above fermenting yeast is at least one selected from Weiss yeast of AB Mauri company in England, WB-06 yeast of Fermentis company in France, and traditional wheat yeast of Munich company in Lallemand Canada.

In order to more clearly and specifically describe the dark wheat beer and the preparation method thereof provided by the embodiments of the present invention, the following description will be made with reference to the specific embodiments.

Comparative example 1

The comparative example provides a triticale beer, the preparation method of which is as follows:

a black wheat beer is prepared from black wheat beer (38 tons of black wheat malt, 0.75 tons of barley malt, 15 tons of black fragrant rice, 0.76 tons of black glutinous rice, 0.4 tons of hop and 45.09 tons of water) by conventional process.

Example 1

The embodiment provides a preparation method of dark wheat beer, which specifically comprises the following steps:

(1) weighing and crushing raw materials: weighing malt according to the weight percentage of 40 percent of Pearson malt, 40 percent of wheat malt, 8 percent of melanoid malt, 8 percent of crystalline malt and 4 percent of chocolate malt, crushing the raw materials, and adding the crushed raw materials into a saccharifying pot;

(2) saccharification: mixing the raw materials at a ratio of 1:3.8, maintaining at 33 deg.C for 15min, 50 deg.C for 20min, 62 deg.C for 30min, and 73 deg.C for 15 min;

(3) and (3) filtering the wort: after saccharification is finished, heating to 75 ℃ after iodine is qualified, and filtering and washing the wort to obtain wort;

(4) boiling wort: boiling wort for 60min, adding flos Lupuli for 2 times, respectively adding flos Lupuli Qingdao and flos Caryophylli for 1 time at initial boiling time and boiling time for 30min, the addition amounts are 0.5kg/kL and 1.0kg/kL respectively;

(5) rotary deposition and fermentation of wort: after boiling, whirling and precipitating the wort, cooling, then oxygenating the wort into a fermentation tank, adding Weiss yeast, and fermenting at the temperature of 20 ℃;

(6) wine liquid cold storage, filtration and filling: and cooling the fermented liquor to 0 ℃, storing, filtering, filling, sterilizing and subpackaging to obtain the dark wheat beer finished product.

Example 2

The embodiment provides a preparation method of dark wheat beer, which specifically comprises the following steps:

(1) weighing and crushing raw materials: weighing malt according to the weight percentage of 35 percent of Pearson malt, 50 percent of wheat malt, 8 percent of melanoid malt, 5 percent of crystalline malt and 2 percent of chocolate malt, crushing the raw materials, and adding the crushed raw materials into a saccharifying pot;

(2) saccharification: mixing the raw materials at a ratio of 1:3.5, and keeping the temperature at 35 deg.C for 20min, 55 deg.C for 30min, 63 deg.C for 30min, and 72 deg.C for 10 min;

(3) and (3) filtering the wort: after saccharification is finished, heating to 75 ℃ after iodine is qualified, and filtering and washing the wort to obtain wort;

(4) boiling wort: boiling wort for 60min, adding flos Lupuli for 2 times, respectively adding flos Lupuli, guava and guding for 1 time when boiling for 30min, respectively, the addition amounts are 0.5kg/kL and 1.2 kg/kL;

(5) rotary deposition and fermentation of wort: after boiling, whirling and precipitating the wort, cooling, then oxygenating the wort into a fermentation tank, adding WB-06 yeast, and fermenting at the temperature of 18 ℃;

(6) wine liquid cold storage, filtration and filling: and cooling the fermented liquor to 0 ℃, storing, filtering, filling, sterilizing and subpackaging to obtain the dark wheat beer finished product.

Example 3

The embodiment provides a preparation method of dark wheat beer, which specifically comprises the following steps:

(1) weighing and crushing raw materials: weighing malt according to the weight percentage of 45 percent of Pearson malt, 40 percent of wheat malt, 8 percent of melanoid malt, 4 percent of crystalline malt and 3 percent of chocolate malt, crushing the raw materials, and adding the crushed raw materials into a saccharifying pot;

(2) saccharification: saccharification: mixing the raw materials at a ratio of 1:4.0, maintaining the temperature at 37 deg.C for 30min, 45 deg.C for 20min, 65 deg.C for 40min, and 70 deg.C for 15 min;

(3) and (3) filtering the wort: after saccharification is finished, heating to 75 ℃ after iodine is qualified, and filtering and washing the wort to obtain wort;

(4) boiling wort: boiling wort for 60min, adding flos Lupuli for 2 times, adding flos Lupuli Fager and Magnus for 1 time respectively at initial boiling time and boiling time for 30min, the addition amounts are 0.5kg/kL and 1.0kg/kL respectively;

(5) rotary deposition and fermentation of wort: after boiling, whirling and precipitating the wort, cooling, then oxygenating the wort into a fermentation tank, adding traditional Munich wheat yeast, and fermenting at the temperature of 22 ℃;

(6) wine liquid cold storage, filtration and filling: and cooling the fermented liquor to 0 ℃, storing, filtering, filling, sterilizing and subpackaging to obtain the dark wheat beer finished product.

Example 4

The embodiment provides a preparation method of dark wheat beer, which specifically comprises the following steps:

(1) weighing and crushing raw materials: weighing malt according to the weight percentage of 35 percent of Pearson malt, 40 percent of wheat malt, 15 percent of melanoid malt, 4 percent of crystalline malt and 6 percent of chocolate malt, crushing the raw materials, and adding the crushed raw materials into a saccharifying pot;

(2) saccharification: saccharification: mixing the raw materials at a ratio of 1:4.0, maintaining at 40 deg.C for 20min, 55 deg.C for 20min, 68 deg.C for 60min, and 73 deg.C for 10 min;

(3) and (3) filtering the wort: after saccharification is finished, heating to 75 ℃ after iodine is qualified, and filtering and washing the wort to obtain wort;

(4) boiling wort: boiling wort for 60min, adding flos Lupuli for 2 times, adding flos Lupuli Qingdao and flos Caryophylli for 1 time respectively at initial boiling time and boiling time for 30min, the addition amounts are 0.5kg/kL and 2.0kg/kL respectively;

(5) rotary deposition and fermentation of wort: after boiling, whirling and precipitating the wort, cooling, then oxygenating the wort into a fermentation tank, adding WB-06 yeast, and fermenting at the temperature of 20 ℃;

(6) wine liquid cold storage, filtration and filling: and cooling the fermented liquor to 0 ℃, storing, filtering, filling, sterilizing and subpackaging to obtain the dark wheat beer finished product.

Example 5

The embodiment provides a preparation method of dark wheat beer, which specifically comprises the following steps:

(1) weighing and crushing raw materials: weighing malt according to the weight percentage of 35 percent of Pearson malt, 45 percent of wheat malt, 8 percent of melanoid malt, 8 percent of crystalline malt and 4 percent of chocolate malt, crushing the raw materials, and adding the crushed raw materials into a saccharifying pot;

(2) saccharification: saccharification: mixing the raw materials at a ratio of 1:3.8, maintaining the temperature at 38 deg.C for 15min, 50 deg.C for 30min, 65 deg.C for 40min, and 73 deg.C for 15 min;

(3) and (3) filtering the wort: after saccharification is finished, heating to 75 ℃ after iodine is qualified, and filtering and washing the wort to obtain wort;

(4) boiling wort: boiling wort for 60min, adding flos Lupuli for 2 times, adding flos Lupuli Fage and GUDING for 1 time respectively at initial boiling time and boiling time for 30min, the addition amounts are 1.0kg/kL and 1.0kg/kL respectively;

(5) rotary deposition and fermentation of wort: after boiling, whirling and precipitating the wort, cooling, then oxygenating the wort into a fermentation tank, adding Weiss yeast, and fermenting at the temperature of 16 ℃;

(6) wine liquid cold storage, filtration and filling: and cooling the fermented liquor to 0 ℃, storing, filtering, filling, sterilizing and subpackaging to obtain the dark wheat beer finished product.

Physical and chemical detection of dark wheat beer:

TABLE 1 results of physicochemical examination of dark wheat beer fractions obtained in examples 1 to 5

As can be seen from Table 1, the dark wheat beer prepared by the embodiment of the invention has the original wheat juice concentration of 10-12P, the chroma of 50-70EBC, the alcoholic strength of 4.0-5.5% vol, the content of 4-VG of 2.0-3.0mg/L, the alcohol ester ratio of 4.0-5.0, and the content of malt aroma substance 2-acetylpyrrole of 170-200 mug/L, which all meet the expected requirements of the dark wheat beer.

Evaluation of flavor

The dark wheat beers obtained in examples 1 to 5 were evaluated for flavor and taste, and the results are shown in Table 2.

TABLE 2 flavor evaluation results of dark wheat beer products obtained in examples 1 to 5

The results in table 2 show that the dark wheat beer provided by the embodiment of the invention is prepared by adopting the pilsner malt, the wheat malt and the melanoidin malt, the crystalline malt and the chocolate malt through the fermentation method, and the finally prepared beer has high 4-VG content, has obvious clove flavor, has malt scorch aroma and baking aroma, is harmonious in alcohol ester and soft in taste, and solves the technical problems of low 4-VG content and weak clove flavor of the current domestic dark wheat beer.