A high-temperature Daqu starter culture and its production method

Abstract

The present application discloses a high-temperature Daqu mother starter and its production method, which relates to the technical field of brewing. A production method of a high-temperature Daqu mother starter includes steps of selecting starter culture, moistening wheat for starter-making, stacking fermentation, and warehousing and storage; it can enhance the activity of functional microorganisms in the mother starter, obtain a mother starter with prominent Maotai flavor and obvious compound flavor, and can effectively strengthen the performance of high-temperature Daqu and improve the quality of Daqu when used for high-temperature Daqu starter-making, ultimately being beneficial to brewing high-quality Baijiu. A high-temperature Daqu mother starter is prepared by the above production method, with prominent Maotai flavor, obvious compound flavor, and excellent quality.

Description

Technical Field

[0001] This application relates to the technical field of brewing, and particularly to a high-temperature Daqu mother koji and its production method. Background Art

[0002] The high-temperature koji-making process is a unique koji-making method for brewing strong-flavor Daqu Baijiu. The high-temperature Daqu prepared by this process, as a saccharifying agent, fermenting agent, and flavor-producing agent for strong-flavor Baijiu, plays a crucial role in the unique flavor and quality of strong-flavor Baijiu. The mother koji is an important raw material in the production process of high-temperature Daqu. As an important inoculant in the production process of high-temperature Daqu, the role of the mother koji in the koji-making process is to inoculate beneficial microorganisms and guide the direction of microbial cultivation in koji-making. During the fermentation process of bacteria, the microorganisms in the mother koji continue to grow, reproduce, and metabolize. It can be said that the quality of the mother koji determines the growth direction of microorganisms in high-temperature Daqu and the quality of Daqu.

[0003] Currently, the inoculation method for high-temperature Daqu koji-making in the industry is mainly to directly use the crushed finished koji as the mother koji. Although this method saves time and effort, the number and performance of its functional microorganisms are limited, and the stability of the finished koji is poor; it is easy to cause an imbalance in the internal microecology of Daqu, affecting the richness of the flavor of the koji medicine. Summary of the Invention

[0004] The purpose of this application is to provide a production method for high-temperature Daqu mother koji, which can enhance the activity of functional microorganisms in the mother koji, obtain a mother koji with prominent sauce flavor and obvious compound flavor, and can effectively strengthen the performance of high-temperature Daqu and improve the quality of Daqu when used for high-temperature Daqu koji-making, ultimately being beneficial to brewing high-quality Baijiu.

[0005] Another purpose of this application is to provide high-temperature Daqu mother koji, which is prepared by the above production method, has prominent sauce flavor, obvious compound flavor, and excellent quality.

[0006] The technical solution of this application is as follows:

[0007] On the one hand, an embodiment of this application provides a production method for high-temperature Daqu mother koji, which includes the following steps:

[0008] Selection of starter koji: Select finished koji with a total number of microorganisms ≥ 2.8×10 8 cfu / g dry koji, the number of Bacillus ≥ 2.0×10 5 cfu / g dry koji, the content of 2,3-dimethylpyrazine ≥ 15.0 μg / g, the content of 2,3,5-trimethylpyrazine ≥ 120.0 μg / g, the physical and chemical indexes of moisture are 9% - 11%, the acidity is 1.0 - 2.0 mmolH+ / 10g, and the saccharifying power is 100 - 200 mg / g.h at 30°C. Crush it to obtain starter koji powder;

[0009] Moistening wheat for koji making: Take wheat, add water for moistening treatment, then crush it to obtain coarse wheat flour; add koji powder and water to the coarse wheat flour, stir and mix, and then send it into the koji mold for treading to obtain koji blanks.

[0010] Piling and fermenting: After sun-drying the koji blanks, send them to the fermentation warehouse for piling into koji piles, and spray water on the koji piles for heat preservation and bacteria cultivation fermentation.

[0011] Taking out of the warehouse and storing: After fermentation is completed, cool down, remove the koji from the warehouse, and send it to the koji storage room for storage to obtain the finished mother koji.

[0012] On the other hand, the embodiment of the present application also provides a high-temperature Daqu mother koji, which is prepared by the production method of a high-temperature Daqu mother koji described above.

[0013] Compared with the prior art, the embodiment of the present application has at least the following advantages or beneficial effects:

[0014] For the first aspect, the embodiment of the present application provides a production method of a high-temperature Daqu mother koji. First, screen the koji starter raw materials through the koji starter selection step: Select the finished product warehouse with better quality of semi-finished products in the warehouse and compliance with temperature and humidity changes as the candidate warehouse, and conduct a comprehensive sensory evaluation of the appearance, cross-section, and fragrance of the finished koji in the candidate warehouse. Prefer the finished koji with more than four-fifths of the surface being yellowish-brown or dark brown, no mildew, consistent cross-section color, being grayish-white, yellowish-gray, and obvious mycelia; rich sauce fragrance, fermented soybean fragrance, and koji fragrance, with prominent style as the candidate sample; conduct tests on microorganisms, flavor substances, and physical and chemical indicators of the candidate sample, and select the finished koji with the total number of microorganisms ≥ 2.8×10 8 cfu / g dry koji, the number of Bacillus ≥ 2.0×10 5 cfu / g dry koji, the content of 2,3-dimethylpyrazine ≥ 15.0 μg / g, the content of 2,3,5-trimethylpyrazine ≥ 120.0 μg / g, the physical and chemical indicators of moisture being 9-11%, acidity being 1.0-2.0 mmolH+ / 10g, and saccharifying power being 100-200 mg / g.h at 30°C. Crush it to obtain koji powder for standby. Then carry out moistening wheat for koji making: Take wheat, add water for moistening and crushing. The sensory requirement for the coarse wheat flour after crushing is "the core is rotten but the skin is not rotten, showing a plum blossom petal shape"; then add koji powder and water to the coarse wheat flour and stir evenly. The sensory requirement is that it can be kneaded into a ball by hand without sticking to the hand, no lumps and white powder; then send it into the koji mold for treading to obtain koji blanks, and the formed koji blanks are required to be tight around and slightly loose in the middle, smooth and flat, without missing corners, and the height of the edge hairs should be the same. Place the formed and treading koji blanks neatly, horizontally and vertically in rows, with reserved gaps on the drying floor for a certain time. After the surface moisture of the koji blanks has subsided, transfer them to the fermentation warehouse for fermentation. Spray an appropriate amount of normal temperature water on the top of the koji pile, close the doors and windows for heat preservation and bacteria cultivation fermentation. After fermentation is completed, cool down and remove the koji from the warehouse, and transfer it to the storage room for storage to obtain the finished mother koji.

[0015] Due to the open co-fermentation of high-temperature Daqu, the various indicators of the finished Daqu vary greatly. Directly using it as the mother Daqu for inoculation is not conducive to the positive regulation and evolution of the functional microorganisms in Daqu making. Therefore, through the step of selecting the starter culture, the starter culture is screened from indicators such as sensory, flavor, physical and chemical, and biological. Substantially, it is the breeding of the functional microorganism flora in Daqu making to achieve the iterative collection and cultivation of the functional microorganisms in Daqu making, and gradually strengthen the in-situ regulation and positive evolution of the internal microecology of Daqu. By using the screened starter culture as the raw material to prepare the mother Daqu, finally, a high-temperature Daqu mother Daqu with high activity of functional microorganisms, prominent soy sauce aroma, and obvious compound aroma can be obtained. Its performance and quality are excellent, which is conducive to further preparing high-quality high-temperature Daqu and ultimately improving the quality of the brewed Baijiu.

[0016] Further, in some embodiments of the present application, in the above-mentioned wheat moistening and Daqu making step, the amount of water added during the wheat moistening treatment is less than or equal to 5% of the weight of the wheat.

[0017] Further, in some embodiments of the present application, in the above-mentioned wheat moistening and Daqu making step, the weight of the starter culture powder added when preparing the Daqu blank is 3-8% of the weight of the coarse wheat flour, and the weight of the water added is 32-40% of the weight of the coarse wheat flour.

[0018] Further, in some embodiments of the present application, after the starter culture powder is prepared through the above-mentioned starter culture selection step, it is first heat-shocked at 25-60 °C for 30-180 min, and then the subsequent steps are carried out.

[0019] In the above embodiments, the bacterial spores, molds and other flora in the high-temperature Daqu survive the extreme environment by forming dormant bodies such as spores and endospores. Only when the environment becomes favorable can the dormant bodies such as spores and endospores break the dormant state and enter the vegetative mode, and then germinate, reproduce and metabolize. Therefore, appropriate heat shock treatment is used to induce the germination of spores and endospores, so that the functional microorganisms can reproduce rapidly, occupy the ecological dominant position, inhibit the growth and reproduction of miscellaneous bacteria, gradually increase the proportion of the functional microorganism flora in the mother Daqu, and promote the positive regulation of the internal microecological balance of Daqu.

[0020] Further, in some embodiments of the present application, in the above-mentioned stacking fermentation step, the starter culture powder is first sprinkled and inoculated on the rice straw and the koji room, the rice straw is laid in the koji room, and then the koji pile is stacked.

[0021] In the above embodiments, using the selected starter culture powder, before the production of the mother Daqu, the production environment is inoculated by suspending dust; the newly added rice straw during the production process and the koji room after installing the koji and turning the koji can be respectively sprinkled and inoculated. In the environments such as the workshop drying hall, the koji room, and the aisle, the starter culture powder is sprinkled manually, and the koji powder is suspended in the air, so that the air and the ground can be enriched with the microorganisms in the starter culture, thereby improving the fermentation effect and helping to further enhance the quality of the finished mother Daqu.

[0022] Further, in some embodiments of the present application, in the above stacking and fermentation step, the koji cakes are stacked into a koji pile in a cross arrangement of three horizontally and three vertically, and straw is used to separate between the koji cakes and between each layer; the koji pile is stacked into a 5-layer and 5-column koji pile.

[0023] Further, in some embodiments of the present application, in the above stacking and fermentation step, the water spraying amount during fermentation is 2-6% of the mass of the koji pile, the fermentation temperature is 60-65 °C, and the humidity is 90-100%.

[0024] In the above embodiment, the doors and windows are closed for heat preservation and bacteria cultivation fermentation. Microorganisms gradually reproduce on the surface of the koji, and the temperature of the koji pile gradually rises. The highest temperature is above 60 °C. During the process, the temperature and humidity of the koji cakes can be adjusted by turning the koji.

[0025] Further, in some embodiments of the present application, in the above step of taking out of the warehouse and storing, after 40 days of fermentation, the temperature is reduced to room temperature, then the koji is disassembled and taken out of the warehouse, and sent to the koji storage room for storage for at least 6 months to obtain the finished mother koji.

[0026] In the above embodiment, after 40 days of bacteria cultivation and fermentation of the koji cakes in the fermentation warehouse, when the temperature of the koji cakes drops to near room temperature and most of the koji blocks are already dry, the koji can be disassembled and taken out of the room. It is required to clean the straw adhered to the koji cakes. After the koji cakes are disassembled and taken out of the warehouse, they are transferred to the koji storage room for storage for more than 6 months to obtain the finished high-temperature Daqu.

[0027] Further, in some embodiments of the present application, in the above step of taking out of the warehouse and storing, after obtaining the finished mother koji, the finished mother koji is further pulverized and heat shocked and strengthened at 40-50 °C.

[0028] In the above embodiment, the finished mother koji obtained by production and preparation is heat shocked and strengthened again to further improve the quality of the mother koji and facilitate the addition and use during the subsequent production of high-temperature Daqu.

[0029] Regarding the second aspect, the embodiments of the present application further provide a high-temperature Daqu mother koji, which is produced and prepared by the above-mentioned production method of a high-temperature Daqu mother koji, and specifically includes steps such as koji selection, wheat moistening and koji making, stacking and fermentation, and taking out of the warehouse and storing. It has prominent sauce aroma, obvious compound aroma, and excellent quality. Specific Embodiments

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below. Those not specified in the embodiments are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or instruments not specified by the manufacturer are all conventional products that can be obtained through commercial purchase.

[0031] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application will be described in detail below with reference to specific embodiments.

[0032] Embodiment 1

[0033] The embodiment of the present application provides a high-temperature Daqu mother starter, which is prepared by the following method:

[0034] Selection of starter: Use the finished product warehouse with better quality of semi-finished products in storage and compliance with temperature and humidity changes as the candidate warehouse. Conduct a comprehensive sensory evaluation of the appearance, cross-section, and fragrance of the finished product koji in the candidate warehouse, and preferably select the finished product koji with more than four-fifths of the surface being yellowish-brown or dark brown, no mildew, consistent cross-section color, being grayish-white or grayish-yellow, and obvious mycelium; with strong sauce fragrance, soy sauce fragrance, and koji fragrance, and prominent style as the candidate samples; conduct tests on the candidate samples for microorganisms, flavor substances, and physical and chemical indicators, and select the finished product koji with a total number of microorganisms ≥ 2.8×10 8 cfu / g dry koji, the number of Bacillus spores ≥ 2.0×10 5 cfu / g dry koji, the content of 2,3-dimethylpyrazine ≥ 15.0 μg / g, the content of 2,3,5-trimethylpyrazine ≥ 120.0 μg / g, and the physical and chemical indicators of moisture being 9% - 11%, acidity being 1.0 - 2.0 mmolH+ / 10g, and saccharifying power being 100 - 200 mg / g.h at 30°C. Crush the selected finished product koji to obtain starter powder; subject the starter powder to heat shock treatment at 25 - 60°C for 30 - 180 min.

[0035] Moistening wheat for koji making: Take wheat and add 2% of the weight of wheat in water for moistening treatment, and then crush it. The sensory requirement for the degree of crushing is "the core is rotten but the skin is not, showing a plum blossom petal shape" to obtain coarse wheat flour; add the heat shock-treated starter powder and water to the coarse wheat flour and stir and mix. The weight of the added starter powder is 3 - 8% of the weight of the coarse wheat flour, and the weight of the added water is 32 - 40% of the weight of the coarse wheat flour. Stir and mix until it reaches the sensory state of being able to be kneaded into a ball by hand without sticking, no lumps and white powder, and then send it into the koji mold for treading to obtain koji blanks. It is required that the formed koji blanks are tight around and slightly loose in the middle, smooth and flat, without missing corners, and the edge hair height is the same;

[0036] Stacking fermentation: First, sprinkle and inoculate the straw and the koji room with the starter powder. Lay the straw in the koji room. After drying the koji blanks, send them to the fermentation warehouse and stack them in a horizontal three and vertical three cross arrangement. Use straw to separate the koji blanks and between each layer to form a koji stack of 5 layers and 5 rows. Then spray water on the koji stack for heat preservation and bacteria cultivation fermentation. The amount of water sprayed during fermentation is 3% of the quality of the koji stack, the fermentation temperature is 65°C, and the humidity is 99%.

[0037] Out - warehouse storage: After 40 days of fermentation, the temperature is reduced to room temperature, then the koji is removed from the warehouse. The straw sticking to the koji cakes is cleaned thoroughly and sent to the koji storage room for 6 - month storage to obtain the finished mother koji. Further, the finished mother koji is pulverized, heat - shocked and strengthened at 50 °C, and then transported to the conventional production workshop for use as the mother koji by addition.

[0038] Comparative Example 1

[0039] This example provides a high - temperature Daqu mother koji. Its production method is based on Example 1. The difference from Example 1 is that in the step of selecting the starter culture, the starter culture powder is not heat - shocked.

[0040] Comparative Example 2

[0041] This example provides a high - temperature Daqu mother koji. Its production method is based on Example 1. The difference from Example 1 is that in the step of selecting the starter culture, the conventional starter culture is used to obtain the starter culture powder after pulverization, and the starter culture powder is heat - shocked.

[0042] Comparative Example 3

[0043] This example provides a high - temperature Daqu mother koji. Its production method is based on Example 1. The difference from Example 1 is that in the stacking fermentation step, the straw and the koji room are not inoculated by spraying the starter culture powder.

[0044] Comparative Example 4

[0045] This example provides a high - temperature Daqu mother koji. Its production method is based on Example 1. The difference from Example 1 is that the step of selecting the starter culture is not carried out, the conventional starter culture is used without heat - shocking; in the stacking fermentation step, the straw and the koji room are not inoculated by spraying the starter culture powder.

[0046] Test Example

[0047] Detection tests were carried out on the high - temperature Daqu mother koji provided in Example 1 and Comparative Examples 1 - 4. The detection items and results are shown in Table 1;

[0048] Table 1

[0049]

[0050]

[0051] It can be seen from the detection tests that the high - temperature Daqu mother koji provided in the examples of this application has better quality and is more conducive to production and use.

[0052] In summary, the embodiment of the present application provides a high-temperature Daqu mother starter and its production method. Through the strain selection step, the strain is screened from indicators such as sensory, flavor, physical and chemical, and biological, which is essentially the breeding of the functional microbial flora for koji making, so as to achieve the iterative collection and cultivation of the functional microorganisms for koji making, and gradually strengthen the in-situ regulation and positive evolution of the internal microecology of Daqu. By using the screened strain as the raw material to prepare the mother starter, finally, a high-temperature Daqu mother starter with high activity of functional microorganisms, prominent soy sauce aroma and obvious compound aroma can be obtained. Its performance and quality are excellent, which is beneficial to further prepare high-quality high-temperature Daqu and finally improve the quality of the brewed Baijiu.

[0053] The embodiments described above are some, but not all, of the embodiments of the present application. The detailed description of the embodiments of the present application is not intended to limit the scope of the present application claimed, but merely represents the selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without making creative efforts shall fall within the scope of protection of the present application.

Claims

1. A production method of high-temperature Daqu mother starter, characterized in that, It includes the following steps: Starter selection: Select koji with a total microbial count ≥ 2.8×10 8 cfu / g dry koji, a Bacillus count ≥ 2.0×10 5 cfu / g dry koji, a 2,3-dimethylpyrazine content ≥ 15.0 μg / g, a 2,3,5-trimethylpyrazine content ≥ 120.0 μg / g, with physical and chemical indices of moisture at 9% - 11%, acidity at 1.0 - 2.0 mmol H+ / 10 g, saccharifying power at 100 - 200 mg / g·h. For the finished koji at 30°C, it is pulverized to obtain starter powder; After obtaining the starter powder through the above-mentioned starter selection step, first perform heat shock treatment on the starter powder at 25-60 °C for 30-180 min, and then proceed with the subsequent steps; Moisten wheat and make koji: Take wheat, add water for wheat moistening treatment, then crush it to obtain coarse wheat flour; add starter powder and water to the coarse wheat flour, stir and mix, and then send it into a koji mold to step on and make koji blanks; Pile up and ferment: First sprinkle and inoculate the straw and koji room with starter powder, lay the straw in the koji room, air-dry the koji blanks and then send them to the fermentation bin to pile up into a koji pile, and spray water on the koji pile for heat preservation and bacterial culture fermentation; Take out of the bin and store: After fermentation is completed, cool down, remove the koji from the bin, send it to the koji storage room for storage to obtain the finished mother koji, crush the finished mother koji, and perform heat shock strengthening at 40-50 °C.

2. The production method of a high-temperature Daqu mother starter according to claim 1, characterized in that, In the step of moistening wheat and making koji, the amount of water added during the wheat moistening treatment is less than or equal to 5% of the weight of the wheat.

3. The production method of a high-temperature Daqu mother koji according to claim 1, characterized in that, In the step of moistening wheat and making koji, the weight of the starter powder added when making koji blanks is 3-8% of the weight of the coarse wheat flour, and the weight of the water added is 32-40% of the weight of the coarse wheat flour.

4. A production method of high-temperature Daqu mother koji according to claim 1, characterized in that, In the step of piling up and fermenting, the koji blanks are piled up into a koji pile with 5 layers and 5 columns in the way of horizontal three and vertical three cross arrangement, and the koji blanks are separated by straw between them and between each layer.

5. The production method of a high-temperature Daqu mother starter according to claim 1, characterized in that, In the step of piling up and fermenting, the amount of water sprayed during fermentation is 2-6% of the quality of the koji pile, the fermentation temperature is 60-65 °C, and the humidity is 90-100%.

6. The production method of a high-temperature Daqu mother starter according to claim 1, characterized in that In the step of taking out of the bin and storing, after 40 days of fermentation, cool down to room temperature, then remove the koji from the bin and send it to the koji storage room for storage for at least 6 months to obtain the finished mother koji.

7. A high-temperature starter culture, characterized in that, It is prepared by the production method of a high-temperature Daqu mother koji as described in any one of claims 1-6.

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