Preparation method of sauce-flavor yeast for making hard liquor
By precisely controlling the preparation process of Maotai-flavor Daqu (a type of starter culture), the problems of monotonous flavor and uneven quality have been solved, resulting in a richer flavor profile and adaptability to seasonal changes, thus improving the quality and stability of Baijiu (Chinese liquor).
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-26
- Publication Date
- 2026-04-03
AI Technical Summary
The existing process for preparing Maotai-flavor liquor has resulted in a lack of flavor compounds, uneven quality, poor fermentation control, and an inability to adapt to seasonal climate changes, leading to unstable quality of the liquor.
The process involves precise control of wheat soaking, crushing, ingredient mixing, koji making, and fermentation, including the use of various natural Chinese herbs and seasonally appropriate amounts of mother koji, combined with straw isolation and temperature gradient turning to ensure sufficient microbial metabolism and flavor accumulation.
This has resulted in a stable proportion of finished product from the sauce-flavored koji, a rich variety of flavor compounds, a complex and full-bodied aroma, and the ability to produce high-quality koji in different seasons, thereby improving the quality of baijiu.
Smart Images
Figure CN121780280A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of brewing starter technology, specifically to a method for preparing soy sauce-flavored starter. Background Technology
[0002] Soy sauce aroma koji is a key saccharification and fermentation agent in the brewing of soy sauce aroma baijiu, and its quality directly determines the flavor, taste, and overall quality of the baijiu. Current technologies for preparing soy sauce aroma koji mostly employ traditional processes, which have the following problems: First, the raw material processing is extensive; the water used for soaking the wheat is often ordinary tap water, and the particle size of the crushed wheat lacks precise control, resulting in poor porosity of the koji embryo, affecting microbial attachment and metabolism. Second, the ingredients are limited; some processes only add a small amount of mother koji or 1-3 kinds of traditional Chinese medicine, resulting in insufficient enrichment of microbial flora and a limited variety of flavor compounds (mostly below 1500), leading to a thin taste in the baijiu. Third, the amount of mother koji used is fixed, without considering the impact of seasonal climate on fermentation; in summer, high temperatures can easily cause problems with the mother koji. Excessive use of koji leads to overgrowth of microorganisms, while insufficient use during the low temperatures of spring and autumn results in slow fermentation, leading to significant quality differences in koji prepared in different seasons. Fourth, the fermentation process is not well controlled, with an indistinct temperature gradient for turning the koji (mostly concentrated between 55-70℃). Some processes use woven cloth to wrap the koji embryos, resulting in an imbalance between air permeability and heat retention. Furthermore, the fermentation cycle is often 30-35 days, leading to insufficient microbial metabolism. Fifth, some processes involve the artificial addition of compound microbial preparations, which, while temporarily improving saccharification, disrupts the flavor harmony of natural fermentation and increases production costs. In addition, the proportion of aged koji in the existing finished koji is difficult to consistently reach over 80%, and the proportion of white and black koji often exceeds 25%, further affecting the quality of baijiu brewing. Therefore, there is an urgent need for a koji preparation process that can precisely control parameters, enrich flavor, and adapt to seasonal changes. Summary of the Invention
[0003] The present invention aims to provide a method for preparing soy sauce-flavored koji, so as to solve the problems of single flavor substances, uneven quality and poor fermentation controllability in the existing soy sauce-flavored koji preparation process.
[0004] To achieve the above objectives, the present invention adopts the following technical solution: a method for preparing soy sauce-flavored koji, comprising the following steps: S1. Wheat rinsing: Select wheat with a moisture content of ≤12.5% and a starch content of ≥60%. Rinse the wheat within 24 hours before production. The amount of water used for rinsing is 1%-3% of the wheat's weight. The water temperature is ambient temperature. The rinsing time is 20-60 minutes. S2. Wheat Crushing: The moistened wheat is crushed using a roller mill. After crushing, the proportion of coarse particles and bran passing through a 20-mesh sieve is 40%-60%, and the proportion of fine powder passing through a 100-mesh copper sieve is 5%-10%. S3. Ingredients: Add mother koji and 18 kinds of natural Chinese herbal medicines to the crushed wheat. The mother koji is koji powder ground from koji that has been stored for 3-6 months. The diameter of the koji powder is ≤3 mm. The amount of mother koji added is 5%-10% of the wheat mass. S4. Mixing: Add water to the mixture after ingredient preparation. The amount of water should be 37%-40% of the wheat mass. Mix well until the mixture can be kneaded into a ball, is not sticky, and crumbles when dropped. The moisture content of the mixed material should be 40-60%. S5, treading: The mixture after mixing is put into the treading mold and treaded to form a turtle-back shaped tread blank. The thickest part in the middle of the tread blank is 13-14 mm. S6. Fermentation of starter culture: After the starter culture has been dried to a certain degree of hardness, it is placed in the warehouse and piled up in six rows and five layers per warehouse, with a spacing of 2-3 mm between the starter culture pieces. Straw is used for isolation. After piling, a small amount of water is sprayed. In spring and winter, the amount of water added is 0.8-1.0% of the wheat mass, and in summer and autumn, the amount of water added is 0.5-0.6% of the wheat mass. After that, the warehouse is turned over twice. The first turning is carried out 7-9 days after the starter culture is placed in the warehouse and the temperature of the starter culture is ≥60℃. The second turning is carried out 7-9 days after the first turning and the temperature of the starter culture is 50-55℃. The total fermentation time is ≥40 days. S7. Separating the starter culture: After fermentation, separate the starter culture from the straw, remove broken starter culture and abnormal starter culture, and obtain the finished sauce-flavored starter culture. The finished sauce-flavored starter culture has a moisture content of ≤12% and an aged starter culture ratio of ≥80%.
[0005] Preferably, as an improvement, in step S3, the amount of mother koji added in spring and autumn is 8%-10% of the wheat mass, and the amount of mother koji added in summer is 5%-7% of the wheat mass.
[0006] Preferably, as an improvement, in step S3, the 18 natural Chinese herbal medicines include Polygonum hydropiper, cinnamon leaves, angelica, field grass, wolfberry, kudzu root, verbena, licorice, dried tangerine peel, mulberry leaves, Atractylodes macrocephala, cloves, pepper, Rehmannia glutinosa, Poria cocos, red bean, almond, and cardamom.
[0007] Preferably, as an improvement, in step S4, the amount of water added can be increased or decreased by 1%-3% depending on the dryness of the mixture and the seasonal climate.
[0008] Preferably, as an improvement, in step S5, the mold size is 37 cm × 28 cm × 6 cm, and the molded blanks are neatly stacked with a spacing of 2 cm between them.
[0009] Preferably, as an improvement, in step S6, the amount of straw used is 4%-7% of the wheat mass, and straw is used to separate the koji embryo from the koji warehouse wall.
[0010] Preferably, as an improvement, in step S6, the amount of water is sprayed twice. The first time, 50% of the total amount is sprayed after piling up three rows of shaped embryos and covering them with straw. The second time, the remaining 50% is sprayed after piling up the remaining three rows of shaped embryos and tidying up the straw in the warehouse. When spraying, more water is sprayed on the four sides and less in the middle.
[0011] Preferably, as an improvement, in step S6, the arrangement of the koji blanks during the turning operation is as follows: the upper and lower layers of koji blanks are interchanged, and each koji blank is rotated 180° to achieve a top-to-bottom swap; the top and bottom layers of koji blanks, as well as the first and last rows of koji blanks in the warehouse, are stacked with their sides standing vertically and their placement direction consistent with the length of the warehouse; the remaining koji blanks are arranged with three pieces of aged koji in each horizontal row and three pieces of aged koji in each vertical column, with the placement positions of adjacent rows and columns staggered and not aligned in a straight line.
[0012] Preferably, as an improvement, the Chishui River water is used in step S1.
[0013] Preferably, as an improvement, in step S7, the abnormal koji is a koji containing black mold, water, mold, or dry burning.
[0014] The advantages of this scheme are: 1) Precise control of multi-step parameters solves the problem of uneven quality, with a stable proportion of finished koji (fermented starter) of ≥80% and uniform physicochemical indicators; 2) 18 kinds of Chinese herbal medicines bring the number of flavor substances to over 2100, solving the problem of single flavor; 3) Seasonal adjustment of the amount of mother koji (8-10% in spring and autumn / 5-7% in summer) and seasonal adaptation of water quantity improve environmental adaptability, and high-quality koji can be prepared in different seasons; 4) Rice straw isolation replaces woven cloth, utilizing the breathability and heat preservation properties of rice straw to avoid the growth of miscellaneous bacteria; 5) ≥40 days of fermentation + temperature gradient turning ensures sufficient metabolism of microorganisms and sufficient accumulation of flavor substances. Attached Figure Description
[0015] Figure 1 This is a two-dimensional gas chromatography-time-of-flight mass spectrometry (GCXGC-TOFMS) analysis spectrum of the finished Daqu-brewed Baijiu from an embodiment of the present invention; Figure 2 This is a pie chart showing the classification of flavor substances in the finished Daqu-brewed Baijiu according to an embodiment of the present invention; Figure 3 This is a comparison chart of quality inspection indicators for finished Daqu-brewed Baijiu (Chinese liquor) according to an embodiment of the present invention. Detailed Implementation
[0016] The following detailed description illustrates the specific implementation method: Example 1: This embodiment describes the production of soy sauce-flavored koji in spring, and includes the following steps: 1) Wheat rinsing: Select wheat with 12.0% moisture and 62% starch content, and use Chishui River water to rinsing the wheat within 24 hours before production. The amount of water for rinsing is 2% of the wheat mass, the water temperature is the ambient temperature (25℃), and the rinsing time is 30 minutes. 2) Wheat crushing: The moistened wheat is crushed using a roller mill. After crushing, 50% of the coarse particles and bran pass through a 20-mesh copper sieve, and 8% of the fine powder passes through a 100-mesh copper sieve. 3) Ingredients: Add mother koji and 18 kinds of natural Chinese herbs (including Polygonum hydropiper, cinnamon leaves, angelica, field grass, wolfberry, kudzu root, verbena, licorice, dried tangerine peel, mulberry leaves, Atractylodes macrocephala, cloves, pepper, Rehmannia glutinosa, Poria cocos, red bean, almond, and cardamom) to the crushed wheat. The mother koji is high-quality aged koji stored for 4 months, ground into koji powder with a diameter of 2 mm. The amount of mother koji added is 9% of the wheat mass (in spring). 4) Mixing: Add water to the mixture after mixing the ingredients. The amount of water should be 38% of the weight of the wheat. Mix well until the mixture can be kneaded into a ball, is not sticky, and crumbles when dropped. 5) Pressing the koji: Put the mixed ingredients into a koji mold of 37 cm × 28 cm × 6 cm and press it to form a turtle-back koji blank. The thickest part in the middle of the koji blank is 13.5 mm. After pressing and shaping, the koji blanks are stacked neatly with a spacing of 2 cm between them. 6) Fermentation of the starter culture: After the starter culture has dried until it does not collapse when pressed with a finger, it is placed in the fermentation chamber through the door and piled up in six rows and four layers per chamber, with a spacing of 2.5 mm between the starter culture pieces. The amount of straw used is 5% of the wheat weight. A straw isolation layer (1.5 cm thick) is used to separate the starter culture pieces from the walls of the fermentation chamber. After piling up three rows of starter culture pieces and covering them with straw, a small amount of water (50% of the total amount) is sprayed on top. The amount of water added is 0.9% of the wheat weight (in spring). After piling up the remaining three rows of starter culture pieces and tidying up the straw in the chamber, the remaining 50% of the water is sprayed on top. When spraying, more water is sprayed on the four sides and less water is sprayed in the center. Eight days after entering the chamber, the temperature of the starter culture pieces is checked and it reaches 62℃. The first turning of the starter culture pieces is then carried out. The upper and lower layers of fermented koji are swapped, and each koji is rotated 180° to achieve a top-to-bottom reversal. The top and bottom layers of koji, as well as the first and last rows of koji in the warehouse, are stacked with their sides upright and aligned with the length of the warehouse. The remaining koji are arranged with 3 blocks of aged koji in each horizontal row and 3 blocks of aged koji in each vertical column. The koji in adjacent rows and columns are staggered and not aligned in a straight line to avoid overlapping. Eight days after the first fermentation, the temperature of the koji is measured at 52℃, and a second fermentation is performed, using the same method as the first. The total fermentation time is 45 days. 7) Separating the starter culture: After fermentation, separate the starter culture from the straw, remove abnormal starter culture containing black mold, water, mold, or dry burning, and obtain the finished sauce-flavored starter culture. The finished starter culture has a moisture content of 11%, an aged starter culture ratio of 85%, a starch content of 56%, an acidity of 2.2, a saccharification power of 200, and a sugar content of 1.0.
[0017] The finished Daqu (a type of starter culture) was used to brew Maotai-flavor liquor, and samples of the liquor were tested. Physicochemical quality inspection (according to GB / T10781.4-2024): alcohol content 52.0%vol (meets the requirement of 53.0±1.0%vol), solids 0.04g / L (≤0.70g / L), total acid 2.34g / L (≥1.50g / L), total esters 3.08g / L (≥2.50g / L), methanol 0.223g / L (≤0.6g / L), ethyl hexanoate 0.01g / L (≤0.30g / L), lead <0.004mg / kg (≤0.5mg / kg), cyanide <1.00mg / L (≤8.0mg / L). All indicators are qualified. Flavor compound detection (using full two-dimensional gas chromatography-time-of-flight mass spectrometry GCXGC-TOFMS): A total of 2135 flavor compounds were identified, including 420 esters (accounting for 20%, including ethyl butyrate, ethyl hexanoate, etc.), 270 alcohols (accounting for 13%, including 1-pentanol, phenylethanol, etc.), 390 carbonyl compounds (accounting for 18%, including phenylacetaldehyde, acetoin, etc.), 98 furans (accounting for 5%), 187 nitrogen compounds (accounting for 9%, including 25 pyrazine compounds, including 2,3,5,6-tetramethylpyrazine), and 72 sulfur compounds (accounting for 3%). The variety of flavor compounds far exceeds that of traditional Daqu, and the aroma of the liquor is complex and full.
[0018] Example 2: This embodiment describes the production of soy sauce-flavored koji in summer, and includes the following steps: 1) Wheat rinsing: Select wheat with 11.5% moisture and 61% starch content, and use Chishui River water to rinsing the wheat within 24 hours before production. The amount of water is 1.5% of the wheat mass, the water temperature is the ambient temperature (30℃), and the rinsing time is 30 minutes. 2) Wheat crushing: The wet wheat is crushed using a roller mill. After crushing, 45% of the coarse particles and bran pass through a 20-mesh copper sieve, and 6% of the fine powder passes through a 100-mesh copper sieve. 3) Ingredients: Add mother koji and 18 kinds of natural Chinese herbs (including Polygonum hydropiper, cinnamon leaves, angelica, field grass, wolfberry and kudzu root) to the crushed wheat. The mother koji is high-quality aged koji stored for 3 months and ground into koji powder with a diameter of 3 mm. The amount of mother koji added is 6% of the wheat mass (in summer). 4) Mixing: Add water to the mixture after mixing the ingredients. Due to the humid summer climate, adjust the amount of water to 36% of the wheat mass (reduce by 1%). Mix well until the mixture can be kneaded into a ball, is not sticky, and crumbles when dropped. 5) Pressing the koji: Put the mixed ingredients into a koji mold of 37 cm × 28 cm × 6 cm, press it to form a turtle-back koji blank, the thickest part of the koji blank in the middle is 13 mm, after pressing and shaping, the koji blanks are stacked neatly with a spacing of 2 cm between them. 6) Fermentation of starter culture: After drying the starter culture until it does not collapse when pressed with a finger, pile it in the fermentation chamber, with six rows and five layers per chamber, and a spacing of 2 mm between the starter culture pieces. The amount of straw used is 6% of the wheat weight. The starter culture pieces are separated from the walls of the fermentation chamber by a straw isolation layer. After piling three rows of starter culture pieces and covering them with straw, spray a small amount of water (50% of the total amount). The amount of water added is 0.55% of the wheat weight (in summer). After piling the remaining three rows of starter culture pieces and tidying up the straw in the chamber, spray the remaining 50% of the water. Seven days after entering the chamber, check the temperature of the starter culture pieces. If it is 61℃, perform the first turning of the chamber. Seven days after the first turning of the chamber, check the temperature of the starter culture pieces. If it is 50℃, perform the second turning of the chamber. The turning method is the same as the first time. The total fermentation time is 42 days. 7) Separating the starter culture: After fermentation, separate the starter culture from the straw, remove abnormal starter culture, and obtain the finished sauce-flavored starter culture. The finished starter culture has a moisture content of 10.5%, an aged starter culture ratio of 82%, a starch content of 55%, an acidity of 1.8, a saccharification power of 180, and a sugar content of 0.8.
[0019] The finished Daqu (a type of starter culture) was used to brew Maotai-flavor liquor, and samples of the liquor were tested. Physicochemical quality inspection: alcohol content 52.5% vol, solids 0.03 g / L, total acid 2.12 g / L, total esters 2.95 g / L, methanol 0.21 g / L, ethyl hexanoate 0.008 g / L, lead <0.004 mg / kg, cyanide <1.00 mg / L, meeting the requirements of GB / T10781.4-2024; Flavor substance detection: A total of 2,110 flavor substances were identified, including 412 esters, 265 alcohols, and 382 carbonyl groups. The types and proportions of flavor substances are similar to those in Example 1, proving that the Daqu produced in summer can still stably guarantee the flavor of the liquor, thus solving the problem of quality fluctuation of Daqu in summer using traditional processes.
[0020] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.
Claims
1. A method for preparing soy sauce-flavored koji, characterized in that, Includes the following steps: S1. Wheat rinsing: Select wheat with a moisture content of ≤12.5% and a starch content of ≥60%. Rinse the wheat within 24 hours before production. The amount of water used for rinsing is 1%-3% of the wheat's weight. The water temperature is ambient temperature. The rinsing time is 20-60 minutes. S2. Wheat Crushing: The moistened wheat is crushed using a roller mill. After crushing, the proportion of coarse particles and bran passing through a 20-mesh sieve is 40%-60%, and the proportion of fine powder passing through a 100-mesh copper sieve is 5%-10%. S3. Ingredients: Add mother koji and 18 kinds of natural Chinese herbal medicines to the crushed wheat. The mother koji is koji powder ground from koji that has been stored for 3-6 months. The diameter of the koji powder is ≤3 mm. The amount of mother koji added is 5%-10% of the wheat mass. S4. Mixing: Add water to the mixture after ingredient preparation. The amount of water should be 37%-40% of the wheat mass. Mix well until the mixture can be kneaded into a ball, is not sticky, and crumbles when dropped. The moisture content of the mixed material should be 40-60%. S5, treading: The mixture after mixing is put into the treading mold and treaded to form a turtle-back shaped tread blank. The thickest part in the middle of the tread blank is 13-14 mm. S6. Fermentation of starter culture: After the starter culture has been dried to a certain degree of hardness, it is placed in the warehouse and piled up in six rows and five layers per warehouse, with a spacing of 2-3 mm between the starter culture pieces. Straw is used for isolation. After piling, a small amount of water is sprayed. In spring and winter, the amount of water added is 0.8-1.0% of the wheat mass, and in summer and autumn, the amount of water added is 0.5-0.6% of the wheat mass. After that, the warehouse is turned over twice. The first turning is carried out 7-9 days after the starter culture is placed in the warehouse and the temperature of the starter culture is ≥60℃. The second turning is carried out 7-9 days after the first turning and the temperature of the starter culture is 50-55℃. The total fermentation time is ≥40 days. S7. Separating the starter culture: After fermentation, separate the starter culture from the straw, remove broken starter culture and abnormal starter culture, and obtain the finished sauce-flavored starter culture. The finished sauce-flavored starter culture has a moisture content of ≤12% and an aged starter culture ratio of ≥80%.
2. The method for preparing a soy sauce-flavored koji according to claim 1, characterized in that: In step S3, the amount of mother koji added in spring and autumn is 8%-10% of the wheat mass, and the amount of mother koji added in summer is 5%-7% of the wheat mass.
3. The method for preparing a soy sauce-flavored koji according to claim 2, characterized in that: In step S3, the 18 natural Chinese herbal medicines include Polygonum hydropiper, Cinnamomum cassia leaves, Angelica sinensis, Clematis chinensis, Lycium barbarum, Pueraria lobata, Verbena officinalis, Glycyrrhiza uralensis, Citrus reticulata peel, Morus alba leaves, Atractylodes macrocephala, Clove, Pepper, Rehmannia glutinosa, Poria cocos, Red bean, Almond, and Amomum tsao-ko.
4. The method for preparing a soy sauce-flavored koji according to claim 3, characterized in that: In step S4, the amount of water added can be increased or decreased by 1%-3% depending on the dryness of the mixture and the seasonal climate.
5. The method for preparing a soy sauce-flavored koji according to claim 4, characterized in that: In step S5, the mold size is 37 cm × 28 cm × 6 cm. After being shaped by stepping, the mold blanks are neatly stacked with a spacing of 2 cm between them.
6. The method for preparing a soy sauce-flavored koji according to claim 5, characterized in that: In step S6, the amount of straw used is 4%-7% of the wheat mass, and straw is used to separate the koji embryo from the koji warehouse wall.
7. The method for preparing a soy sauce-flavored koji according to claim 6, characterized in that: In step S6, the amount of water is sprayed twice. The first time, 50% of the total amount is sprayed after piling up three rows of shaped embryos and covering them with straw. The second time, the remaining 50% is sprayed after piling up the remaining three rows of shaped embryos and tidying up the straw in the warehouse. When spraying, more water is sprayed on the four sides and less in the middle.
8. The method for preparing a soy sauce-flavored koji according to claim 7, characterized in that: In step S6, during the warehouse turning operation, the koji blanks are arranged as follows: the upper and lower layers of koji blanks are interchanged, and each koji blank is rotated 180° to achieve a top-to-bottom swap; the top and bottom layers of koji blanks, as well as the first and last rows of koji blanks in the warehouse, are stacked with their sides standing vertically and their orientation consistent with the length of the warehouse; the remaining koji blanks are arranged with three pieces of aged koji in each horizontal row and three pieces of aged koji in each vertical column, and the koji blanks in adjacent rows and columns are staggered and not aligned in a straight line.
9. The method for preparing a soy sauce-flavored koji according to claim 8, characterized in that: The Chishui River water is used in step S1.
10. The method for preparing a soy sauce-flavored koji according to claim 9, characterized in that: In step S7, the abnormal koji embryo is one containing black mold, water, mold, or dry burning.