A process for aging baijiu (Chinese white liquor) using plant burial.

Abstract

This invention relates to a plant-based aging process for baijiu (Chinese white liquor), belonging to the field of brewing technology. The method of this invention uses new liquor and aged baijiu as raw materials, and adds stone. The stone is modified by soaking in a mixed enzymatic hydrolysate of Solomon's seal leaf and amla fruit. The components of Solomon's seal leaf and amla fruit, as well as the enzymatic hydrolysate, adhere to the pores and surface of the stone, and participate in the aging process in conjunction with the characteristics of the stone. During the aging process, the liquor is first stored in an underground cellar, and then buried in sandy loam soil. Ophiopogon japonicus or Liriope muscari are planted on top of the sandy loam soil to promote the aging reaction, which can produce an aged baijiu with excellent flavor and unique taste.

Description

Technical Field

[0001] This invention belongs to the field of brewing technology, specifically relating to a process for brewing baijiu (Chinese white liquor) using plant burial aging. Background Technology

[0002] Baijiu, a typical representative of traditional Chinese beverages, boasts a long history and unique brewing techniques. Aging is a crucial step in baijiu production, imbuing it with a deeper charm. Newly brewed baijiu often has a rough, harsh taste and lacks harmonious flavors. Aging techniques are essential for refining and polishing it.

[0003] The aging of baijiu (Chinese white liquor) typically requires specific containers, such as earthenware jars. Earthenware jars have tiny pores, allowing for slow exchange of substances between the liquor and the external environment. For example, oxygen from the air can pass through the jar into the liquor, causing the alcohols to slowly oxidize and produce aldehydes, acids, and other substances. For instance, ethanol is oxidized to acetaldehyde, and further to acetic acid. These substances, at certain concentrations, can improve the flavor of the liquor, making it more mellow and full-bodied. Some low-boiling-point undesirable components in the liquor, such as hydrogen sulfide and thiols, can also evaporate through the pores, reducing the pungent odor of new liquor.

[0004] Long-term aging allows ample time for the various components in the liquor to react and blend. In the early stages of aging, large molecules in the liquor, such as ethyl esters of higher fatty acids, gradually polymerize and precipitate, reducing the liquor's turbidity. Over time, the various flavor components interact and reach equilibrium. Esters are an important source of aroma in baijiu, and during aging, the proportions of different esters undergo subtle changes, resulting in a more harmonious aroma. For example, adjusting the content and proportion of esters such as ethyl hexanoate and ethyl lactate makes the aroma of baijiu more complex and richer than it could have been.

[0005] The technology behind aged baijiu integrates knowledge from multiple disciplines such as microbiology, chemistry, and physics. Through meticulous control of environmental and temporal factors, new liquor is transformed into a fine brew with unique flavor and mellow taste. Various baijiu aging methods have emerged, resulting in a rich variety of flavors. However, the flavor and taste of currently aged baijiu are still somewhat lacking. Due to the inherent characteristics of baijiu components, storage conditions, and auxiliary materials, the smoothness of the taste and the freshness of the aroma are insufficient, and the flavor variations fail to meet consumer demands. Summary of the Invention

[0006] To address the shortcomings of existing aged baijiu (Chinese white liquor) in terms of flavor and taste, and the inability to meet consumer demands for flavor variation, this invention provides a plant-based aging process for baijiu. This process involves soaking and modifying stone with a mixed enzymatic hydrolysate of Solomon's seal leaves and amla fruit. The components of the Solomon's seal leaves and amla fruit, along with the enzymatic hydrolysate, adhere to the pores and surface of the stone, participating in the aging process in conjunction with the stone's characteristics. During the aging process, the stone is buried in soil, and special green plants are planted on top to promote the aging reaction, resulting in a unique and highly flavorful aged baijiu. The specific technical solution is as follows: A process for aging baijiu (Chinese liquor) using plant burial techniques includes the following steps: S1, Raw Material Selection: The base spirit for baijiu is made from newly brewed liquor; the auxiliary spirit for baijiu is made from aged baijiu; stone materials; S2, Stone pretreatment: S2.1: Cut the selected stone into blocks with a side length range of 5cm to 8cm, wash them with pure water, and then soak them in 75% to 80% edible alcohol for 24h to 30h. Take out the stone and rinse it with pure water to remove the alcohol, and you will get purified stone. S2.2: According to the mass ratio of Solomon's seal leaf: Phyllanthus emblica fruit = (1~5): (10~15), mix and crush Solomon's seal leaf and Phyllanthus emblica fruit to obtain a slurry; add 6 to 8 times the mass of water to the slurry, mix evenly to obtain a liquid; add pectinase, cellulase and tanninase to the liquid, enzymatically hydrolyze at 40℃~50℃ for 2h~3h, heat up to inactivate the enzyme, cool to room temperature, filter with an 800-900 mesh sieve to obtain an enzymatic hydrolysate, put the purified stone into the enzymatic hydrolysate, soak at 60℃~70℃ for 40h~50h to obtain modified stone; S3, Stone Addition and Base Wine Injection: Take the modified stone out of the enzymatic hydrolysate, and then put 4kg to 6kg of the modified stone into a large earthenware vat. Mix 80L to 90L of base liquor and 10L to 15L of auxiliary liquor evenly, and then pour it into the earthenware vat to ensure that the stone is completely submerged in the liquor. S4, sealed storage and aging: The mouth of the ceramic vat is sealed with food-grade silicone, and then the mouth is wrapped with kraft paper. The ceramic vat is then placed in a temperature- and humidity-controlled underground wine cellar, with the temperature controlled between 15℃ and 18℃ and the humidity maintained between 70% and 75%, for 150 to 180 days. After that, it is buried in the soil for 2 to 3 years, with the top of the vat 1m to 1.5m from the ground, for aging. S5, Filtering: After aging, the liquor is filtered using a filter to remove stone particles and impurities, resulting in filtered aged white liquor.

[0007] In S1 of the above technical solution, the base liquor is a 53° sauce-flavored new liquor made from sorghum; the auxiliary liquor is a 54° rich-flavored liquor aged for three years.

[0008] In S2.1 of the above technical solution, the liquid level of the edible alcohol is more than 10cm above the upper surface of the stone.

[0009] In S2.2 of the above technical solution, the liquid level of the enzymatic hydrolysate is more than 10cm above the surface of the purified stone.

[0010] In the above technical solution, the stone is selected from at least one of maifanite, diatomite and meteorite.

[0011] In S2.2 of the above technical solution, the amount of pectinase added is 0.01% to 0.05% of the slurry mass, the amount of cellulase added is 0.02% to 0.1% of the slurry mass, and the amount of tanninase added is 0.005% to 0.02% of the slurry mass.

[0012] In S2.2 of the above technical solution, the activity of the pectinase is 50,000 U / g to 100,000 U / g; the activity of the cellulase is 10,000 U / g to 20,000 U / g; and the activity of the tanninase is 50,000 U / g to 100,000 U / g.

[0013] In S2.2 of the above technical solution, the temperature for inactivating the enzyme is 95°C and the time is 10 min to 15 min.

[0014] In S3 of the above technical solution, the capacity of the ceramic vat is 150L to 180L, and the wall thickness of the ceramic vat is 5cm to 8cm. Before use, the ceramic vat is rinsed with pure water, then sterilized by fumigation with high-temperature steam for 30min to 40min, and then dried.

[0015] In the above technical solution, the stone material selected is a combination of maifan stone and diatomite, and the mass ratio of maifan stone to diatomite is (3~6):(0.5~1.5).

[0016] In S4 of the above technical solution, the wine cellar is stirred every 28 to 30 days during storage, using a wooden stirring rod at a speed of 10 to 15 r / min, with each stirring session lasting 5 to 10 minutes, and then resealed after stirring.

[0017] In S4 of the above technical solution, the soil is sandy loam with a pH value of 6.0 to 7.5, and the soil surface is planted with Liriope muscari or Ophiopogon japonicus.

[0018] In S5 of the above technical solution, the filtration is to filter the wine by sequentially using filter screens with pore sizes of 0.5mm, 0.2mm and 0.1mm.

[0019] The plant burial aging process for Baijiu (Chinese white liquor) of the present invention has the following advantages compared with the prior art: First, stone can enhance the taste. Stone has a unique physical structure and composition that can influence the molecular structure and interactions of the liquor, making the taste of baijiu (Chinese white liquor) more mellow, delicate, and fragrant, increasing the complexity and layers of flavor. The presence of stone accelerates the aging process of baijiu, allowing it to reach an effect similar to long-term natural aging in a shorter time, enabling new liquor to acquire the flavor and quality of aged liquor more quickly, saving aging time and costs. Stone containing magnesium, calcium, iron, silicate minerals, etc., will release small amounts of minerals into the liquor during contact, supplementing the trace elements needed by the human body and increasing the nutritional value of the liquor.

[0020] Second, soaking the stone in edible alcohol removes impurities, dust, and potential contaminants from its surface, ensuring cleanliness and preventing contamination of the wine. Edible alcohol also has sterilizing and disinfecting properties, further guaranteeing the stone's hygiene and safety. The enzymatic hydrolysate made from Solomon's seal leaves and amla fruit contains various bioactive components. When the stone is soaked in this solution, it interacts with these components, altering the stone's surface properties and structure, making it more readily react with the wine and thus enhancing the stone's effect on the wine. The pectinase, cellulase, and tanninase in the hydrolysate break down the cell wall components of Solomon's seal leaves and amla fruit, releasing more bioactive substances such as polyphenols and flavonoids. These substances adhere to the stone's surface and pores and are subsequently released into the wine, adding more flavor and health benefits.

[0021] Thirdly, the unique flavor of amla fruit, when added to liquor, can enhance its aroma and taste, enriching its flavor and increasing its appeal. Amla fruit itself possesses properties such as clearing heat and relieving sore throat, moistening the lungs and resolving phlegm, promoting saliva production and quenching thirst, stimulating appetite and aiding digestion, and lubricating the intestines and promoting bowel movements. After being infused into liquor, these health benefits are preserved to some extent, allowing consumers to enjoy certain health benefits while drinking the liquor. Some components of amla fruit interact with other components in the liquor, stabilizing the liquor and making it more stable during storage and aging, less prone to turbidity or sedimentation.

[0022] IV. The leaves of the Solomon's Seal (Polygonatum odoratum) possess a unique, refreshing aroma. Adding them to the liquor imparts a fresh fragrance that blends with the original aroma of the baijiu, creating a unique complex aroma and enhancing the flavor and quality of the liquor. In traditional Chinese medicine, Solomon's Seal leaves have certain medicinal properties, such as clearing heat and relieving irritability, promoting fluid production and diuresis. Although the amount added to the liquor is small, it still provides some potential health benefits, meeting consumers' demand for healthy beverages. When used together with Amla fruit, Solomon's Seal leaves work synergistically to enhance the effect of the enzymatic hydrolysate, allowing for more complete modification of the stone and thus better leveraging the stone's influence on the liquor.

[0023] V. Pectinase can break down pectin in Solomon's seal leaves and amla fruit, cellulase can break down cellulose in cell walls, and tanninase can break down tannins. The combined action of these enzymes disrupts the cell wall structure of plant cells, making it easier to release the active ingredients within the cells and improving the extraction efficiency of bioactive components. Pectin, cellulose, and tannins in wine can affect its taste, making it cloudy, astringent, or rough. Enzymatic hydrolysis of these substances can reduce astringency and turbidity, resulting in a smoother and more delicate taste. The products of enzymatic hydrolysis interact with other components in the wine to form more stable complexes, contributing to improved stability and clarity.

[0024] VI. The rich aroma type of baijiu possesses a unique fragrance and flavor, distinct from the style of sauce-aroma baijiu. Adding it as a complementary spirit to sauce-aroma baijiu allows for a fusion of the two aroma types, enriching and enhancing the overall flavor profile. The palate characteristics of the rich aroma type complement those of the sauce-aroma baijiu, harmonizing the overall taste, making it smoother and more harmonious, reducing the harshness of the sauce-aroma baijiu, and improving palatability. Blending different aroma types of baijiu together increases complexity and mystique, satisfying consumers' demand for diverse and personalized baijiu, and elevating the quality and value of the liquor.

[0025] VII. The soil possesses excellent heat and moisture retention properties. Burying the earthenware jars in the soil creates a relatively stable temperature and humidity environment for the wine. This constant temperature and humidity condition is beneficial for the aging process, allowing various chemical reactions and physical changes in the wine to proceed more smoothly, thus promoting quality improvement. The tiny pores in the soil provide a certain supply of oxygen, but the amount is relatively small and slow, creating a micro-oxygen environment. This micro-oxygen environment is conducive to oxidation and esterification reactions in the wine, resulting in a richer aroma and a more mellow taste. The soil also has a certain filtering effect, adsorbing impurities and off-flavors from the wine, making it purer and clearer, further enhancing its quality.

[0026] 8. Liriope and Ophiopogon japonicus are herbaceous plants whose root systems stabilize the soil, preventing erosion and maintaining soil fertility and structure. Simultaneously, their growth absorbs moisture and nutrients from the soil, creating an ecological balance with the wine in the vat, which is beneficial for aging. The transpiration of these plants regulates the humidity and temperature of the soil surface, providing a more suitable aging environment for the wine. Furthermore, the photosynthesis of these plants releases oxygen, improving the air environment around the soil and also having a positive impact on wine aging. Detailed Implementation

[0027] The present invention will be further described below with reference to specific implementation examples, but the present invention is not limited to these embodiments.

[0028] Example 1 A process for aging baijiu (Chinese liquor) using plant burial techniques includes the following steps: S1, Raw Material Selection: The base liquor for the baijiu is a 53° sauce-flavored new liquor made from sorghum; the auxiliary liquor is a 54° rich-flavored baijiu aged for three years; the stone material is maifan stone and diatomite, with a mass ratio of maifan stone:diatomite = 4:1. S2, Stone pretreatment: S2.1: Cut the selected stone into blocks with a side length of about 6cm, wash them with purified water, and then soak them in 75% edible alcohol. The alcohol level should be 10cm above the top surface of the stone. Soak for 24 hours, then take out the stone and rinse it with purified water to remove the alcohol, thus obtaining purified stone. S2.2: The ratio of Solomon's seal leaf to amla fruit is 1:10. The Solomon's seal leaf and amla fruit are mixed and crushed to obtain a slurry. Water with a mass ratio of 6 times the slurry is added to the slurry and mixed evenly to obtain a liquid. 0.01% pectinase, 0.02% cellulase and 0.005% tanninase by mass of the liquid are added to the liquid. The mixture is enzymatically hydrolyzed at 40℃ for 2 hours, then heated to 95℃ to inactivate the enzymes for 10 minutes. After cooling to room temperature, it is filtered through an 800-mesh sieve to obtain an enzymatic hydrolysate. The purified stone is placed in the enzymatic hydrolysate, with the liquid level 10 cm above the surface of the purified stone. It is soaked at 60℃ for 40 hours to obtain the modified stone. The pectinase has an activity of 50,000 U / g; the cellulase has an activity of 10,000 U / g; and the tanninase has an activity of 50,000 U / g. S3, Stone Addition and Base Wine Injection: Prepare a large ceramic vat with a capacity of 150L and a wall thickness of 5cm. Rinse it clean with pure water, then sterilize it by fumigating it with high-temperature steam for 30 minutes, and then dry it. Take the modified stone out of the enzymatic hydrolysate, then put 4 kg of the modified stone into a ceramic vat, mix 80 L of baijiu base liquor and 10 L of baijiu auxiliary liquor evenly, and then pour it into the ceramic vat to ensure that the stone is completely submerged in the liquor. During the storage period in the cellar, the wine is stirred once every 28 days using a wooden stirring rod at a speed of 10 r / min for 5 minutes each time, and then resealed after stirring. S4, sealed storage and aging: The mouth of the ceramic vat is sealed with food-grade silicone, and then the mouth is wrapped with kraft paper. The ceramic vat is placed in a temperature- and humidity-controlled underground cellar, with the temperature controlled at about 16°C and the humidity maintained at about 72%, for 150 days. Then it is buried in the soil for 2 years. The soil is sandy loam with a pH value of 6.0 and the burial depth is 1m from the top of the vat to the ground. Ophiopogon japonicus is planted on the soil surface for aging. S5, Filtering: After aging, the liquor is filtered sequentially using filters with pore sizes of 0.5mm, 0.2mm, and 0.1mm to remove stones and impurities, resulting in filtered aged baijiu.

[0029] Example 2 A process for aging baijiu (Chinese liquor) using plant burial techniques includes the following steps: S1, Raw Material Selection: The base liquor for the baijiu is a 53° sauce-flavored new liquor made from sorghum; the auxiliary liquor is a 54° rich-flavored baijiu aged for three years; the stone material is maifan stone and diatomite, with a mass ratio of maifan stone:diatomite = 3:0.5. S2, Stone pretreatment: S2.1: Cut the selected stone into blocks with a side length of about 5cm, wash them with purified water, and then soak them in 75% edible alcohol. The level of the edible alcohol should be 15cm above the surface of the stone. Soak for 24 hours, then take out the stone and rinse it with purified water to remove the alcohol, thus obtaining purified stone. S2.2: According to the mass ratio of Solomon's seal leaf: Phyllanthus emblica fruit = 5:13, mix and crush Solomon's seal leaf and Phyllanthus emblica fruit to obtain a slurry; add 8 times the mass of water to the slurry and mix evenly to obtain a liquid; add 0.01% pectinase, 0.1% cellulase and 0.005% tanninase by mass of the liquid to the liquid, enzymatically hydrolyze at 50℃ for 2 hours, heat to 95℃ to inactivate the enzyme for 15 minutes, cool to room temperature, and filter through an 800-mesh sieve to obtain an enzymatic hydrolysate. Put the purified stone into the enzymatic hydrolysate, with the liquid level of the enzymatic hydrolysate 15cm above the surface of the purified stone, and soak at 60℃ for 50 hours to obtain the modified stone; The pectinase has an activity of 50,000 U / g; the cellulase has an activity of 20,000 U / g; and the tanninase has an activity of 50,000 U / g. S3, Stone Addition and Base Wine Injection: Prepare a large ceramic vat with a capacity of 180L and a wall thickness of 5cm. Rinse it clean with pure water, then sterilize it by fumigating it with high-temperature steam for 40 minutes, and then dry it. Take the modified stone out of the enzymatic hydrolysate, then put 4 kg of the modified stone into a large earthenware vat. Mix 90 L of base liquor and 10 L of auxiliary liquor evenly, and then pour the mixture into the earthenware vat, ensuring that the stone is completely submerged in the liquor. During the storage period in the cellar, the wine is stirred once every 30 days using a wooden stirring rod at a speed of 10 r / min for 10 minutes each time, and then resealed after stirring. S4, sealed storage and aging: The mouth of the ceramic vat is sealed with food-grade silicone, and then the mouth is wrapped with kraft paper. The ceramic vat is placed in an underground wine cellar with constant temperature and humidity, with the temperature controlled at about 17°C and the humidity maintained at about 70%, for 150 days. Then it is buried in the soil for 3 years. The soil is sandy loam with a pH value of 6.0, and the burial depth is 1.5m from the top of the vat to the ground. Ophiopogon japonicus is planted on the soil surface for aging. S5, Filtering: After aging, the liquor is filtered sequentially using filters with pore sizes of 0.5mm, 0.2mm, and 0.1mm to remove stones and impurities, resulting in filtered aged baijiu.

[0030] Example 3 A process for aging baijiu (Chinese liquor) using plant burial techniques includes the following steps: S1, Raw Material Selection: The base liquor for the baijiu is a 53° sauce-flavored new liquor made from sorghum; the auxiliary liquor is a 54° rich-flavored baijiu aged for three years; the stone material is maifan stone and diatomite, with a mass ratio of maifan stone:diatomite = 6:1.5. S2, Stone pretreatment: S2.1: Cut the selected stone into blocks with a side length of about 8cm, wash them with pure water, and then soak them in 78% edible alcohol. The level of the edible alcohol should be 12cm above the top surface of the stone. Soak for 26 hours, then take out the stone and rinse it with pure water to remove the alcohol, thus obtaining purified stone. S2.2: According to the mass ratio of Solomon's seal leaf: Phyllanthus emblica fruit = 3:13, mix and crush Solomon's seal leaf and Phyllanthus emblica fruit to obtain a slurry; add 7 times the mass of water to the slurry, mix evenly to obtain a liquid; add 0.03% pectinase, 0.06% cellulase and 0.01% tanninase by mass of the liquid to the liquid, enzymatically hydrolyze at 45℃ for 2.5h, heat to 95℃ to inactivate enzymes for 12min, cool to room temperature, filter through an 800-mesh sieve to obtain an enzymatic hydrolysate, put the purified stone into the enzymatic hydrolysate, the liquid level of the enzymatic hydrolysate is 12cm above the surface of the purified stone, soak at 65℃ for 45h to obtain modified stone; The pectinase has an activity of 100,000 U / g; the cellulase has an activity of 20,000 U / g; and the tanninase has an activity of 50,000 U / g. S3, Stone Addition and Base Wine Injection: Prepare a large ceramic vat with a capacity of 160L and a wall thickness of 6cm. Rinse it clean with pure water, then sterilize it by fumigating it with high-temperature steam for 35 minutes, and then dry it. Take the modified stone out of the enzymatic hydrolysate, then put 5 kg of the modified stone into a ceramic vat, mix 85 L of baijiu base liquor and 12 L of baijiu auxiliary liquor evenly, and then pour it into the ceramic vat to ensure that the stone is completely submerged in the liquor. During the storage period in the cellar, the wine is stirred once every 30 days using a wooden stirring rod at a speed of 12 r / min for 8 minutes each time, and then resealed after stirring. S4, sealed storage and aging: The mouth of the ceramic vat is sealed with food-grade silicone, and then the mouth is wrapped with kraft paper. The ceramic vat is placed in a temperature- and humidity-controlled underground cellar, with a temperature of about 18°C ​​and a humidity of about 75%, for 165 days. Then it is buried in the soil for 2.5 years. The soil is sandy loam with a pH of 7.0 and the burial depth is 1.2m from the top of the vat to the ground. Ophiopogon japonicus is planted on the soil surface for aging. S5, Filtering: After aging, the liquor is filtered sequentially using filters with pore sizes of 0.5mm, 0.2mm, and 0.1mm to remove stones and impurities, resulting in filtered aged baijiu.

[0031] Example 4 A process for aging baijiu (Chinese liquor) using plant burial techniques includes the following steps: S1, Raw Material Selection: The base liquor for the baijiu is a 53° sauce-flavored new liquor made from sorghum; the auxiliary liquor is a 54° rich-flavored baijiu aged for three years; the stone material is maifan stone and diatomite, with a mass ratio of maifan stone:diatomite = 3:1.5. S2, Stone pretreatment: S2.1: Cut the selected stone into blocks with a side length of about 7cm, wash them with pure water, and then soak them in 80% edible alcohol. The level of the edible alcohol should be 10cm above the surface of the stone. Soak for 30 hours, then take out the stone and rinse it with pure water to remove the alcohol, thus obtaining purified stone. S2.2: According to the mass ratio of Solomon's seal leaf: Phyllanthus emblica fruit = 1:15, mix and crush Solomon's seal leaf and Phyllanthus emblica fruit to obtain a slurry; add 6 times the mass of water to the slurry, mix evenly to obtain a liquid; add 0.05% pectinase, 0.02% cellulase and 0.02% tanninase by mass of the liquid to the liquid, enzymatically hydrolyze at 40℃ for 3h, heat to 95℃ to inactivate enzymes for 10min, cool to room temperature, filter through a 900-mesh sieve to obtain an enzymatic hydrolysate, put the purified stone into the enzymatic hydrolysate, the liquid level of the enzymatic hydrolysate is 10cm above the surface of the purified stone, soak at 70℃ for 40h to obtain modified stone; The pectinase has an activity of 100,000 U / g; the cellulase has an activity of 10,000 U / g; and the tanninase has an activity of 100,000 U / g. S3, Stone Addition and Base Wine Injection: Prepare a large ceramic vat with a capacity of 150L and a wall thickness of 8cm. Rinse it clean with pure water, then sterilize it by fumigating it with high-temperature steam for 30 minutes, and then dry it. Take the modified stone out of the enzymatic hydrolysate, then put 6 kg of the modified stone into a large earthenware vat. Mix 80 L of base liquor and 15 L of auxiliary liquor evenly, and then pour the mixture into the earthenware vat to ensure that the stone is completely submerged in the liquor. During the storage period in the cellar, the wine is stirred once every 28 days using a wooden stirring rod at a speed of 15 r / min for 5 minutes each time, and then resealed after stirring. S4, sealed storage and aging: The mouth of the ceramic vat is sealed with food-grade silicone, and then the mouth is wrapped with kraft paper. The ceramic vat is placed in a temperature- and humidity-controlled underground cellar, with the temperature controlled at approximately 15°C and the humidity at approximately 73%, for 180 days. Then it is buried in the soil for 2 years. The soil is sandy loam with a pH of 7.5, and the burial depth is 1 meter from the top of the vat to the ground. Ophiopogon japonicus is planted on the soil surface for aging. S5, Filtering: After aging, the liquor is filtered sequentially using filters with pore sizes of 0.5mm, 0.2mm, and 0.1mm to remove stones and impurities, resulting in filtered aged baijiu.

[0032] Example 5 A process for aging baijiu (Chinese liquor) using plant burial techniques includes the following steps: S1, Raw Material Selection: The base liquor for the baijiu is a 53° sauce-flavored new liquor made from sorghum; the auxiliary liquor is a 54° rich-flavored baijiu aged for three years; the stone material is maifan stone and diatomite, with a mass ratio of maifan stone:diatomite = 6:0.5. S2, Stone pretreatment: S2.1: Cut the selected stone into blocks with a side length of about 6cm, wash them with purified water, and then soak them in 80% edible alcohol. The level of the edible alcohol should be 15cm above the surface of the stone. Soak for 30 hours, then take out the stone and rinse it with purified water to remove the alcohol, thus obtaining purified stone. S2.2: According to the mass ratio of Solomon's seal leaf: Phyllanthus emblica fruit = 5:14, mix and crush Solomon's seal leaf and Phyllanthus emblica fruit to obtain a slurry; add 8 times the mass of water to the slurry and mix evenly to obtain a liquid; add 0.05% pectinase, 0.1% cellulase and 0.02% tanninase by mass of the liquid to the liquid, enzymatically hydrolyze at 50℃ for 3 hours, heat to 95℃ to inactivate the enzyme for 15 minutes, cool to room temperature, and filter through a 900-mesh sieve to obtain an enzymatic hydrolysate; put the purified stone into the enzymatic hydrolysate, with the liquid level of the enzymatic hydrolysate 15cm above the surface of the purified stone, and soak at 70℃ for 50 hours to obtain the modified stone; The pectinase has an activity of 100,000 U / g; the cellulase has an activity of 20,000 U / g; and the tanninase has an activity of 100,000 U / g. S3, Stone Addition and Base Wine Injection: Prepare a large ceramic vat with a capacity of 180L and a wall thickness of 8cm. Rinse it clean with pure water, then sterilize it by fumigating it with high-temperature steam for 40 minutes, and then dry it. Take the modified stone out of the enzymatic hydrolysate, then put 6 kg of the modified stone into a large earthenware vat. Mix 90 L of base liquor and 15 L of auxiliary liquor evenly, and then pour the mixture into the earthenware vat to ensure that the stone is completely submerged in the liquor. During the storage period in the cellar, the wine is stirred once every 30 days using a wooden stirring rod at a speed of 15 r / min for 10 minutes each time, and then resealed after stirring. S4, sealed storage and aging: The mouth of the ceramic vat is sealed with food-grade silicone, and then the mouth is wrapped with kraft paper. The ceramic vat is placed in a temperature- and humidity-controlled underground cellar, with a temperature of about 16°C and a humidity of about 71%, for 180 days. Then it is buried in the soil for 3 years. The soil is sandy loam with a pH of 7.5 and the burial depth is 1.5m from the top of the vat to the ground. Ophiopogon japonicus is planted on the soil surface for aging. S5, Filtering: After aging, the liquor is filtered sequentially using filters with pore sizes of 0.5mm, 0.2mm, and 0.1mm to remove stones and impurities, resulting in filtered aged baijiu.

[0033] The total acidity of the base liquor used in the above embodiments was 1.85 g / L and the total lipids were 2.62 g / L; the total acidity of the auxiliary liquor was 1.96 g / L and the total lipids were 2.73 g / L.

[0034] Comparative Example 1 In the preparation method, no stone is added; other methods and parameters are the same as in Example 1.

[0035] Comparative Example 2 In the preparation method, step S2.2 is omitted, and modified stone is not prepared. The modified stone in step S3 is directly replaced by purified stone. Other methods and parameters are the same as in Example 1.

[0036] Comparative Example 3 In the preparation method, no Phyllanthus emblica fruit is added; other methods and parameters are the same as in Example 1.

[0037] Comparative Example 4 In the preparation method, no Solomon's seal leaves are added; other methods and parameters are the same as in Example 1.

[0038] Comparative Example 5 In the preparation method, the slurry is not enzymatically hydrolyzed, and the purified stone is directly soaked after filtration; other methods and parameters are the same as in Example 1.

[0039] Comparative Example 6 In the preparation method, no baijiu (Chinese liquor) is added as an auxiliary liquor; other methods and parameters are the same as in Example 1.

[0040] Comparative Example 7 In the preparation method, the earthenware vat is not buried in the soil, but stored directly in the underground wine cellar for 2 years; other methods and parameters are the same as in Example 1.

[0041] Comparative Example 8 In the preparation method, no plants are planted on the soil surface above the ceramic vat; instead, black plastic film is used for covering.

[0042] The aged baijiu prepared in each of the above embodiments and comparative examples was tasted and tested.

[0043] I. Detection and evaluation of appearance, flavor, and texture: 1. Appearance: Pour the wine into a clean, colorless, and transparent glass. Observe it against a white paper background using front, top, and bottom views.

[0044] Appearance Evaluation: Grade 1 - The liquid is clear and transparent, free of any impurities or suspended matter, with a uniform color that falls within the normal color range for this type of wine. Grade 2 - The liquid is relatively clear and transparent, with very slight impurities or slightly uneven color, but this does not affect the overall appearance. Grade 3 - The liquid is mostly transparent, with a small amount of inconspicuous suspended matter or slightly abnormal color. Grade 4 - The liquid is cloudy, contains sediment, or has a noticeably abnormal color. The evaluation results are shown in Table 1 below.

[0045] 2. Aroma: Pour the wine into a glass. First, raise the glass and place it 15mm below your nose, with the rim tilted slightly inward at a 30° angle. Lower your head slightly and inhale slowly and steadily to smell the still aroma. Then, gently swirl the glass to increase the release and concentration of the aroma, and smell it again.

[0046] Aroma Evaluation: Level 1 - Rich and harmonious soy sauce aroma and rich fragrance; the unique stone and processing aromas blend perfectly with the original aroma of the wine; complex and layered aroma; long-lasting aroma in an empty glass. Level 2 - Relatively obvious soy sauce aroma and rich fragrance; some unique aroma can be detected, but the blending is slightly lacking; the aroma is relatively long-lasting but not very complex; long-lasting aroma in an empty glass. Level 3 - Possesses the basic characteristics of soy sauce aroma and rich fragrance; the unique aroma is not prominent; the aroma is relatively weak or slightly uncoordinated; short-lasting aroma in an empty glass. Level 4 - Weak aroma; off-flavors or unpleasant odors; uncoordinated aroma; poor aroma in an empty glass. The evaluation results are shown in Table 1 below.

[0047] 3. Taste and mouthfeel: Take 1mL of wine each time and let the wine stay in your mouth for 5 seconds. Let the tip and sides of your tongue come into contact with the wine first, and then spread the wine evenly on the surface and back of your tongue by swirling your tongue.

[0048] Taste and mouthfeel evaluation: Level 1 - Smooth and mellow on the palate, with minimal irritation; sweet, sour, bitter, and astringent flavors are balanced and harmonious; long and pleasant aftertaste; full-bodied taste; harmonious unity of all flavors. Level 2 - Relatively smooth on the palate, with a certain degree of richness; flavor elements are relatively harmonious, but one flavor is slightly prominent; long aftertaste; overall comfortable taste. Level 3 - Somewhat irritating on the palate; thin mouthfeel; average harmony between flavors; short aftertaste; no obvious defects but no outstanding advantages. Level 4 - Strongly irritating on the palate; rough mouthfeel; conflicting flavors; bitter, short, and unpleasant aftertaste. The evaluation results are shown in Table 1 below.

[0049] II. Detection of alcohol content, total acid, total esters, and trace elements: (1) The alcohol content was measured using an alcohol meter; (2) The total acid and total ester content were measured using a gas chromatograph; the results are shown in Table 1 below. (3) The trace element content was measured using atomic absorption spectrometry; the results are shown in Table 2 below.

[0050] III. Health indicator testing: Gas chromatography and atomic absorption spectrometry were used to detect the content of harmful substances such as methanol, fusel oil, lead, and cadmium in the wine. The test results are shown in Table 2 below.

[0051] Table 1 Test Results of Aged Baijiu

[0052] The results above show that the aged baijiu from Examples 1 to 5 possesses excellent flavor and taste, with high total acid and total lipid content. The addition of modified stone and the unique brewing process result in a richer, smoother, and more mellow taste, producing unique flavor variations. Combining the characteristics of both soy sauce aroma and rich aroma baijiu, the combination with the stone creates a unique and harmonious style with high recognizability and individuality. The comparative examples demonstrate that changes in the preparation process all negatively impacted the flavor and taste to varying degrees.

[0053] Table 2 Results of Trace Elements and Harmful Substances Detection

[0054] The results above show that the trace element content in the aged baijiu of Examples 1 to 5 is moderate, and the harmful substances meet the qualified standards, indicating safety and reliability. The results of Comparative Example 1 show that without the addition of stone, the trace element content is slightly lower.

Claims

1. A plant buried aging liquor process, characterized in that, The preparation method includes the following steps: S1, Raw Material Selection: The base liquor for the baijiu is a 53° sauce-flavored new baijiu made from sorghum; the auxiliary liquor is a 54° rich-flavored baijiu aged for three years; the stone materials are maifanite and diatomite, with a mass ratio of maifanite to diatomite of (3-6):(0.5-1.5). S2, Stone pretreatment: S2.1: Cut the selected stone into blocks with a side length range of 5cm to 8cm, wash them with pure water, and then soak them in 75% to 80% edible alcohol for 24h to 30h. Take out the stone and rinse it with pure water to remove the alcohol, and you will get purified stone. S2.2: According to the mass ratio of Solomon's seal leaf: Phyllanthus emblica fruit = (1~5): (10~15), mix and crush Solomon's seal leaf and Phyllanthus emblica fruit to obtain a slurry; add 6 to 8 times the mass of water to the slurry, mix evenly to obtain a liquid; add pectinase, cellulase and tanninase to the liquid, enzymatically hydrolyze at 40℃~50℃ for 2h~3h, heat up to inactivate the enzyme, cool to room temperature, filter with an 800-900 mesh sieve to obtain an enzymatic hydrolysate, put the purified stone into the enzymatic hydrolysate, soak at 60℃~70℃ for 40h~50h to obtain modified stone; S3, Stone Addition and Base Wine Injection: Take the modified stone out of the enzymatic hydrolysate, and then put 4kg to 6kg of the modified stone into a large earthenware vat. Mix 80L to 90L of base liquor and 10L to 15L of auxiliary liquor evenly, and then pour it into the earthenware vat to ensure that the stone is completely submerged in the liquor. S4, sealed storage and aging: The mouth of the ceramic vat is sealed with food-grade silicone, and then wrapped with kraft paper. The vat is then placed in a temperature- and humidity-controlled underground cellar, with the temperature controlled between 15℃ and 18℃ and the humidity maintained between 70% and 75%, for 150 to 180 days. After that, it is buried in the soil for 2 to 3 years. The soil should be sandy loam with a pH value between 6.0 and 7.5, and the soil surface should be planted with liriope or iris. The burial depth is 1m to 1.5m from the ground for aging. S5, Filtering: After aging, the liquor is filtered using a filter to remove stone particles and impurities, resulting in filtered aged white liquor.

2. The plant buried aging liquor-making process according to claim 1, characterized in that, In S2.1, the liquid level of the edible alcohol is more than 10cm above the upper surface of the stone. And / or, in S2.2, the surface of the enzymatic hydrolysate is more than 10 cm above the surface of the purified stone.

3. The plant burial aging process for Baijiu (Chinese liquor) according to claim 1, characterized in that, In S2.2, the amount of pectinase added is 0.01% to 0.05% of the slurry mass, the amount of cellulase added is 0.02% to 0.1% of the slurry mass, and the amount of tanninase added is 0.005% to 0.02% of the slurry mass.

4. The plant burial aging process for Baijiu (Chinese liquor) according to claim 1, characterized in that, In S2.2, the pectinase has an enzyme activity of 50,000 U / g to 100,000 U / g; the cellulase has an enzyme activity of 10,000 U / g to 20,000 U / g; and the tanninase has an enzyme activity of 50,000 U / g to 100,000 U / g.

5. The plant burial aging process for Baijiu (Chinese liquor) according to claim 1, characterized in that, In S2.2, the temperature for inactivating the enzyme is 95°C, and the time is 10 min to 15 min.

6. The plant burial aging process for Baijiu (Chinese liquor) according to claim 1, characterized in that, In S3, the capacity of the ceramic vat is 150L to 180L, and the wall thickness of the ceramic vat is 5cm to 8cm. Before use, the ceramic vat is rinsed with pure water, then sterilized by fumigation with high-temperature steam for 30min to 40min, and then dried.

7. The plant burial aging process for Baijiu (Chinese liquor) according to claim 1, characterized in that, In S4, the wine is stirred every 28 to 30 days during storage in the cellar using a wooden stirring rod at a speed of 10 to 15 rpm for 5 to 10 minutes each time. After stirring, the wine is resealed.

8. The plant burial aging process for Baijiu (Chinese liquor) according to claim 1, characterized in that, In S5, the filtration is performed by sequentially filtering the wine using filter screens with pore sizes of 0.5mm, 0.2mm, and 0.1mm.

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