Eucommia ulmoides wood controllable carbonization-gradient hooping phenol fragrant barrel for white spirit and application thereof

Abstract

The invention discloses an eucommia ulmoides wood controllable carbonization-gradient hooping phenol fragrance barrel for white spirit, and belongs to the technical field of wine brewing equipment. In order to solve the problems that a traditional oak barrel is high in cost, an eucommia wood barrel is incomplete in pretreatment, uneven in structural stress and poor in flavor controllability, eucommia wood with the tree age of 18-22 years is adopted as a base material, and pretreatment of segmented steaming, microwave degreasing and gradient drying is conducted; the barrel body is provided with a controllable carbonization modification layer, a 304 stainless steel gradient hoop enhancement layer, a triple-closing sealing layer and a flow guide groove functional layer, and a composite fragrant juice activation process is matched. The barrel can dissolve active ingredients of eucommia ulmoides such as geniposide and aucubin, the leakage rate is smaller than or equal to 0.05%, the content of guaiacol is increased by 42 times compared with a traditional pottery jar, the cost is reduced by 60% compared with an imported oak barrel, and the barrel is suitable for high-quality ageing of Chinese high-degree white spirit.

Description

Technical Field

[0001] This invention relates to the field of brewing equipment manufacturing technology, specifically proposing a controllable carbonization-gradient binding phenolic aroma barrel made of Eucommia ulmoides wood for aging Chinese high-proof liquor, and also relates to the application method of the phenolic aroma barrel. Background Technology

[0002] In the brewing industry, wooden barrels are traditional aging containers for spirits. Among them, oak barrels, commonly used in Europe and America, have become the mainstream choice because they can impart a certain mellowness and aroma to the spirit. However, oak barrels have significant limitations: the raw materials rely on imports, there are no natural oak resources in China, and the oak trees need to be over 30 years old and the wood needs to be naturally air-dried for 6-24 years, resulting in long raw material cycles, high costs, and unstable supply. At the same time, oak barrels only produce limited flavor substances through toasting, which is difficult to meet the demand for flavor complexity in Chinese high-proof liquor. Furthermore, the equidistant clamping structure is not adapted to the stress differences of the "bulging" barrel body, and leakage is prone to occur due to stress concentration in high-alcohol environments.

[0003] Domestic baijiu aging primarily relies on earthenware jars and stainless steel containers. While earthenware jars can promote aging, they cannot actively impart woody flavors and have low aging efficiency. Stainless steel containers, with their strong sealing properties, prevent oxygen and flavor exchange, resulting in slow aging. In recent years, Eucommia ulmoides wood has become a potential alternative to oak due to its short growth cycle (growing in over 5 years), abundant domestic resources, and content of active ingredients. However, direct barrel making with Eucommia ulmoides wood still presents technical challenges: incomplete wood pretreatment results in high levels of tannins and impurities, making it prone to leaching harmful substances at high alcohol concentrations; difficulty in controlling moisture content leads to barrel cracking; the traditional single-layer structure and equidistant clamping of oak barrels are not adapted to the mechanical properties of Eucommia ulmoides wood, leading to concentrated side pressure in the middle of the barrel and easy leakage; the sealing system cannot meet the leakage prevention requirements at high alcohol concentrations, and flavor release is uncontrollable, resulting in poor consistency of the aged liquor; the smooth inner wall of the barrel leads to insufficient microcirculation of the liquor, resulting in low aging efficiency. These problems make it difficult for existing containers to simultaneously ensure the safety, flavor, and stability of high-proof baijiu aging. Summary of the Invention

[0004] In view of this, the present invention proposes a controllable carbonization-gradient binding phenolic aroma barrel for baijiu made of Eucommia ulmoides wood and its application method, aiming to solve the problems of poor material compatibility, unstable structure, low flavor controllability, and insufficient aging efficiency of existing high-proof baijiu aging containers.

[0005] The technical solution of the present invention is implemented as follows: The present invention provides a controllable carbonization-gradient binding phenolic aroma barrel for baijiu (Chinese liquor) and its application method.

[0006] In some embodiments, the phenolic aroma barrel includes a barrel body substrate layer and a primary sealing structure; the barrel body substrate layer is a barrel-shaped structure, formed by splicing together Eucommia ulmoides wood boards. The raw material for the Eucommia ulmoides wood boards is Eucommia ulmoides trees aged 18-22 years with a diameter at breast height ≥20cm, and requires pretreatment by segmented steaming (105℃±2℃ constant temperature for 3 hours), microwave degreasing (2450MHz irradiation for 120 seconds), and gradient drying (55℃ for 12 hours, 45℃ for 24 hours, 35℃ for 12 hours, moisture content 14%±0.5%); the primary sealing structure is a mortise and tenon joint structure, located at both ends of the barrel body substrate layer, used to connect the barrel body and the barrel lid, with a fitting accuracy of ±0.05mm, and the mating surface is the radial end face of the barrel body end and the mating end face of the barrel lid.

[0007] In some embodiments, a modified layer is provided on the inner surface of the barrel substrate layer. This modified layer is a controllable carbonized microporous layer, which is formed by graded carbonization of the inner surface of the substrate using a carbonization device, with a thickness of 0.2mm-0.5mm. The graded carbonization can be selected from light (180℃ for 15 minutes, micropores ≤50μm), medium (220℃ for 20 minutes, micropores 80μm-120μm), or deep (260℃ for 25 minutes, micropores 150μm-200μm) processes to adapt to different aging flavor requirements.

[0008] In some embodiments, a reinforcing layer is provided on the outer surface of the barrel substrate layer. This reinforcing layer is a 304 stainless steel strip clamping structure with a stainless steel strip thickness of 1.2 mm and a width of 40 mm. The clamping method is a non-equidistant gradient clamping, distributed along the height of the barrel substrate layer. The spacing between adjacent stainless steel strips in the area from the barrel opening down to 1 / 3 of the height and the area from the barrel bottom up to 1 / 3 of the height is 120 mm, and the spacing between adjacent stainless steel strips in the area from 1 / 3 to 2 / 3 of the height of the barrel body is 74 mm, in order to balance the stress distribution of the barrel body.

[0009] In some embodiments, a secondary seal is provided between the tenon and mortise mating surfaces of the primary sealing structure. The secondary seal is a food-grade silicone gasket (Shore hardness 60±5, thickness 3mm), the gasket shape matches the mating surface and completely covers the mating surface; at the same time, a tertiary seal (304 stainless steel flange) is provided on the outer side of both ends of the barrel base layer. The inner diameter of the flange matches the outer diameter of the barrel port. A preload force of ≥25N·m is applied by tightening the bolts, which together with the primary and secondary seals constitute a triple composite sealing system.

[0010] In some embodiments, the inner surface of the modified layer is provided with a functional layer, which is an array of inner wall guiding grooves; the grooves are evenly distributed around the circumference of the barrel substrate layer, with a depth of 2mm and a width of 5mm for each groove, and a center-line spacing of 8mm between adjacent grooves; the groove inclination angle is the angle (15°) between the groove center line and the barrel axis, and it is inclined from the barrel opening to the bottom along the height of the barrel to promote microcirculation of the wine.

[0011] In some embodiments, the phenolic aroma barrel also includes a barrel activation process, which includes aroma preparation and aroma infiltration: For aroma preparation, 15g of cinnamon, 25g of osmanthus, 50g of chrysanthemum, and 20g of dried tangerine peel are mixed to form a compound aromatic plant. This is then soaked in 50-degree edible alcohol at a ratio of 1g:22mL for 10 days at room temperature. After filtration, the liquid is collected by vacuum distillation (48℃, -0.08MPa). Simultaneously, the Eucommia ulmoides wood is ultrasonically cleaned and the liquid is collected by vacuum distillation (58℃, -0.08MPa). The two are mixed at a volume ratio of 2.5:1 to obtain the activated aroma. For aroma infiltration, the aroma is sprayed onto the inner wall of the barrel using a spray device with a nozzle diameter of 0.5mm. After sealing, compressed air at 0.18MPa is injected and maintained for 8 minutes. The barrel is then left to stand for 10 days to complete the activation process.

[0012] In some embodiments, the application method of the phenolic aroma barrel includes base liquor selection, barrel filling operation and aging treatment: select 60% vol light aroma type baijiu as base liquor, filter it through a 0.45 μm filter membrane; put the base liquor into the phenolic aroma barrel, with the volume occupying 95% of the barrel's internal volume and leaving 5% headspace; during aging, you can choose to age at room temperature (20℃-25℃, ventilation 0.5m / s-1m / s) for 7 months, or at a constant temperature (22℃±1℃, humidity 60%-65%) for 18 months, or at a long-term room temperature for 20 months.

[0013] In some embodiments, the lid of the phenolic aroma barrel integrates a micro-oxygen exchange device and a sensor integration module: the micro-oxygen exchange device is a one-way valve with a 0.22μm breathable membrane located on the edge of the lid, which controls the oxygen exchange rate inside the barrel at 0.5mL / day to 1mL / day; the sensor integration module is located inside the lid and includes a temperature sensor (measuring 0℃-50℃), a pressure sensor (measuring 0MPa-0.3MPa), and a wireless transmission unit, which can transmit monitoring data in real time.

[0014] In some embodiments, the 50-degree edible alcohol used in the barrel activation process is food-grade and filtered through a 0.22μm filter membrane; the spraying device operates at a pressure of 0.2MPa-0.3MPa to ensure that the aroma is sprayed evenly in a mist form.

[0015] The present invention has the following advantages over the prior art: This invention effectively overcomes the shortcomings of existing baijiu aging containers through targeted structural design and process optimization: In terms of material compatibility, it solves the problems of harmful substances leaching and easy cracking of the barrel under high alcohol content when traditional eucommia wood is used for direct barrel making. Compared with imported oak barrels, it does not rely on scarce imported resources, and the raw material cycle is significantly shortened. In terms of flavor control, it breaks through the limitations of the single flavor of oak barrels and the passive release of flavor in traditional eucommia wood barrels. Through controllable carbonization and activation processes, it achieves active control of flavor release and can also give the liquor a unique complex aroma, enhancing the flavor layers of high-proof baijiu. In terms of structural stability, the non-equidistant gradient clamping design adapts to the stress differences of the barrel body, and the triple-layer sealing system solves the problem of leakage of high-alcohol liquor. Compared with traditional equidistant clamping and single sealing, the long-term stability of the barrel is significantly improved. In terms of aging efficiency, the inner wall guiding groove promotes the microcirculation of the liquor, shortens the aging cycle, and avoids the problem of low efficiency in traditional earthenware jar aging. Meanwhile, this invention uses locally sourced Eucommia ulmoides wood as raw material, reducing raw material and usage costs, ensuring the self-control of the liquor enterprise's supply chain, and providing technical support for liquor flavor innovation and green brewing, thus promoting the upgrade of liquor aging containers from "passive adaptation" to "active empowerment". Attached Figure Description To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of the cylindrical body of the present invention; Figure 2 This is a graph showing the changes in the body indicators of the wine after 18 months of aging, as described in Example 3 of the present invention. Figure 3 This is a graph showing the changes in the body indicators of the wine after 20 months of aging, as described in Example 5 of the present invention.

[0017] In the diagram: 1-Barrel base material layer, 2-Primary sealing structure, 3-Secondary sealing structure, 4-Tertiary sealing structure, 5-Modified layer, 6-Reinforcing layer, 11-Functional layer. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] Example 1 Step 1: Selection and pretreatment of Eucommia ulmoides wood boards Thirty pieces of Eucommia ulmoides wood, aged 20 years, with a diameter at breast height of 22 cm, no knots, and uniform grain, were longitudinally cut into boards 95 cm long, 8 cm wide, and 5 cm thick. The boards were placed in a steam generator and steamed at a constant temperature of 105℃±2℃ for 3 hours. After removal, they were transferred to a 2450MHz microwave generator for directional irradiation for 120 seconds to degrease. The degreased boards were then placed in a drying equipment, first heated at a constant temperature of 55℃ for 12 hours, then cooled to 45℃ and heated at a constant temperature for 24 hours, and finally cooled to 35℃ and heated at a constant temperature for 12 hours. After drying, the moisture content of the boards was measured to be 14%±0.5%.

[0020] Step 2: Preparation of the barrel substrate layer and basic hoop assembly Pre-treated Eucommia ulmoides wood boards are tightly spliced ​​together to form a barrel base layer with an inner diameter of 560mm and a height of 960mm. The boards are heated with steam (108℃) for 35 minutes to improve their toughness. The upper edge of the barrel is tightened by hydraulic equipment and reinforced with traditional equidistant iron hoops (120mm spacing, 1.2mm thickness). The barrel is then dried at 85℃ for 12 hours, at 75℃ for 24 hours, and at 65℃ for 12 hours to set its shape.

[0021] Step 3: Primary + Secondary Sealing Assembly The mortise and tenon structure is processed at both ends of the barrel base layer (fitting accuracy ±0.05mm). A food-grade silicone gasket with a Shore hardness of 60±5 and a thickness of 3mm is cut to match the shape of the mortise and tenon mating surface. The gasket is then attached to the radial end face of the barrel body port. Finally, a round barrel lid is assembled so that the barrel lid mating surface is tightly fitted with the silicone gasket and the mortise and tenon structure.

[0022] Step 4: Bottling and Aging A light-aroma baijiu with an alcohol content of 60% vol was selected as the base liquor. After being filtered through a 0.45μm filter membrane, it was poured into the barrel through the filling hole on the barrel lid. The volume of the base liquor was controlled to be 95% of the barrel's internal volume (225L), leaving 5% headspace. The filling hole was sealed with a perforated silicone stopper, and the barrel was placed in an environment of 20-25℃ and a ventilation rate of 0.8m / s for 7 months of room temperature aging.

[0023] Example 2a Step 1: Substrate pretreatment and barrel preparation Same as steps 1-2 of Example 1 (the basic clamping still uses traditional equidistant iron clamps).

[0024] Step 2: Preparation of the modified layer (controllable carbonization microporous layer) A hot air circulating carbonization furnace was used to perform medium carbonization treatment on the inner wall surface (inner surface of the substrate layer) of the barrel body: the carbonization temperature was set to 220℃ and held for 20 minutes to form a carbonization layer with a thickness of 0.3mm±0.1mm on the wall surface, and the micropore size was detected to be 80-120μm.

[0025] Step 3: Processing of functional layer (guide groove) Using a CNC engraving machine, a channeling groove array is processed on the inner wall of the modified layer: the grooves are evenly distributed along the circumference of the barrel, with a depth of 2mm and a width of 5mm for each groove, and a center-line spacing of 8mm between adjacent grooves; the engraving angle is adjusted so that the center line of the groove forms a 10° angle with the axis of the barrel, and extends slopingly from the barrel opening to the bottom along the height of the barrel.

[0026] Step 4: Sealing, Filling, and Aging Same as steps 3-4 of Example 1 (aged at room temperature for 7 months).

[0027] Parallel groups 2b and 2c are also provided. Example 2b uses a 15° angle, and example 2c uses a 20° angle.

[0028] Example 3 Step 1: Substrate pretreatment and barrel preparation Same as step 1 of Example 1 (pretreatment parameters for Eucommia ulmoides wood boards are consistent).

[0029] Step 2: Preparation of modified and functional layers Same as steps 2-3 of Example 2 (medium carbonization + 15° guide trench).

[0030] Step 3: Assemble the gradient bracing reinforcement layer Select 304 stainless steel strips with a thickness of 1.2mm and a width of 40mm, and non-equidistantly clamp them along the height direction of the barrel's base layer: from the barrel opening down to 1 / 3 of the barrel height (approximately 320mm), the spacing between adjacent stainless steel strips is 120mm; from 1 / 3 to 2 / 3 of the barrel height (320-640mm), the spacing between adjacent stainless steel strips is 74mm; from the bottom of the barrel up to 1 / 3 of the barrel height (640-960mm), the spacing between adjacent stainless steel strips is 120mm; a total of 6 stainless steel strips are clamped to ensure a tight fit to the outer wall of the barrel without any looseness.

[0031] Step 4: Triple-layer sealing assembly After completing the first-level tenon and mortise fitting (fit accuracy ±0.05mm) and the second-level silicone gasket (same as in Example 1), 304 stainless steel flanges (with inner diameter matching the outer diameter of the barrel port and 8 bolt holes evenly distributed around the flange) are fitted on the outer side of both ends of the barrel body. Bolts are passed through the bolt holes and tightened. A preload of 25 N·m is applied by a torque wrench to press the flanges against the fitting parts of the barrel body and the barrel lid.

[0032] Step 5: Wooden Barrel Activation Process ① Preparation of aromatic juice: Take 15g of cinnamon, 25g of osmanthus, 50g of chrysanthemum, and 20g of dried tangerine peel by weight, and mix them into a compound aromatic plant. Add 50-degree food-grade edible alcohol (total mass of compound aromatic plants to volume ratio of alcohol 1g:22mL) and soak at room temperature for 10 days. Remove plant residues with a filter and collect the soaking liquid. Place it in a vacuum distillation apparatus and distill under vacuum at 48℃ and -0.08MPa for 2.5 hours, collecting 500mL of distillate. Separately, take the purified water (ultrasonic cleaning water) used to clean the Eucommia ulmoides wood board before the segmented steaming in step 1 of Example 1, place it in a vacuum distillation apparatus, and distill under vacuum at 58℃ and -0.08MPa for 2.5 hours, collecting 1.0L of distillate. Mix the two distillates at a volume ratio of 2.5:1 to obtain the activated aromatic juice.

[0033] ② Aroma Infiltration: Fill a spray device with a nozzle diameter of 0.5mm and a working pressure of 0.25MPa with activated aroma. Spray the aroma evenly onto the inner wall of the barrel (the surface of the modified layer and the functional layer) through the filling hole of the barrel lid. During spraying, keep the distance between the nozzle and the inner wall at 18cm±2cm to ensure complete coverage of the aroma. Seal the filling hole with a perforated silicone stopper. Inject compressed air into the barrel through the hole of the silicone stopper to maintain the pressure inside the barrel at 0.18MPa for 8 minutes. Remove the compressed air system and seal the barrel for 10 days to complete the activation.

[0034] Step 6: Bottling and Aging The same base wine filtration and barreling procedures as in Example 1 were followed; the barrels were placed in a constant temperature aging cellar at 22℃±1℃ and 62% relative humidity for 18 months.

[0035] Example 4 Three parallel experiments were set up (4a, 4b, 4c). Except for the carbonization parameters of the modified layer, the other preparation steps (substrate pretreatment, gradient bonding, composite sealing, activation process, and wine aging) were the same as in Example 3. The specific carbonization parameters are as follows: 4a (light carbonization): carbonization temperature 180℃, holding time 15 minutes, carbonization layer thickness 0.2mm, micropore size ≤50μm; 4b (moderate carbonization): Same as Example 3 (220℃ / 20 minutes, micropores 80-120μm); 4c (deep carbonization): carbonization temperature 260℃, holding time 25 minutes, carbonization layer thickness 0.5mm, micropore size 150-200μm; Aging conditions: Same as in Example 3 (aged at constant temperature for 18 months).

[0036] Example 5 Step 1: Preparation of the full-structure phenolic aroma barrel Same as steps 1-5 of Example 3 (full structure + activation process).

[0037] Step 2: Monitoring Module Integration An installation hole is made on the edge of the circular barrel lid, and a one-way valve (micro oxygen exchange device) with a breathable membrane with a pore size of 0.22μm is embedded. The valve parameters are adjusted to make the oxygen exchange rate in the barrel 0.8mL / day. A sensor integrated module (including a temperature sensor, a pressure sensor and a wireless transmission unit) is attached to the inside of the barrel lid. The temperature sensor has a measurement range of 0-50℃, the pressure sensor has a measurement range of 0-0.3MPa, and the wireless transmission unit is connected to an external monitoring terminal.

[0038] Step 3: Bottling and Aging Monitoring The base wine filtration and barreling operations were the same as in Example 1; the barrels were aged for 20 months in an environment of 20-25℃ and a ventilation rate of 0.8m / s, during which the temperature and pressure data inside the barrels were recorded in real time through an external monitoring terminal.

[0039] Parallel groups 5a and 5b were also set up, with the oxygen exchange rate in the tank of Example 5a being 0.3 mL / day and the oxygen exchange rate in the tank of Example 5b being 1.2 mL / day, and other conditions being the same as in Example 5.

[0040] Comparative Example 1 Step 1: Oak Barrel Preparation Made from imported oak trees aged 30 years, naturally air-dried for 5 years, cut into boards and spliced ​​together to form a barrel base layer with an inner diameter of 560mm and a height of 960mm. Iron hoops are evenly spaced (120mm apart). The inside of the barrel is traditionally baked (200℃ / 10 minutes), and the barrel lid is assembled using a single mortise and tenon joint.

[0041] Step 2: Bottling and Aging The base wine was filtered and bottled in the same manner as in Example 1 (base wine volume accounted for 95%), and then aged at room temperature for 7 months in an environment with a temperature of 20-25℃ and a ventilation of 0.8m / s.

[0042] Comparative Example 2 Step 1: Treatment of Eucommia ulmoides wood planks and preparation of barrel body Eucommia ulmoides wood planks (20-year-old trees, 22cm diameter at breast height) were selected from the same materials as in Example 1 and were only air-dried naturally for 6 months (moisture content 20%±2%) without segmented steaming or microwave degreasing. The subsequent assembly of the barrel body, equidistant iron hoops, and first-level + second-level sealing was the same as in Example 1.

[0043] Step 2: Bottling and Aging The base wine and aging conditions (7 months at room temperature) are the same as in Example 1.

[0044] Comparative Example 3 Step 1: Substrate pretreatment and preparation of modified and functional layers Same as steps 1-3 of Example 2 (medium carbonization + flow channel).

[0045] Step 2: Equidistant clamping and sealing 304 stainless steel strips (same specifications as in Example 3) are used to be equidistantly clamped along the height of the barrel (120mm spacing in all areas), and triple-layer sealing is used (same as in Example 3); subsequent activation process, wine aging (same as in Example 3, constant temperature for 18 months).

[0046] Comparative Example 4 Step 1: Full structure preparation (excluding activation process) The same steps 1-4 (substrate pretreatment, modified layer, gradient bonding, composite sealing) as in Example 3 were performed, but the barrel activation process was not carried out (activation fragrance was not sprayed on the inner wall of the barrel).

[0047] Step 2: Bottling and Aging The same base wine and aging conditions as in Example 3 (constant temperature for 18 months).

[0048] Comparative Example 5 Step 1: Full structure fabrication (excluding sealing) Same as steps 1-3 of Example 3 (substrate pretreatment, modified layer, gradient clamping), but only uses primary tenon seal (without secondary silicone gasket and tertiary flange).

[0049] Step 2: Bottling and Aging The same base wine and aging conditions as in Example 3 (constant temperature for 18 months).

[0050] Performance verification 1. Leakage rate test During the aging process, the total mass of the barrel is weighed every 30 days using an electronic balance (accuracy 0.1g) to calculate the mass loss rate (leakage rate = (initial total mass - total mass on day n) / initial total mass × 100%). The average value is taken after the aging process is completed. If the leakage rate is > 0.5%, it is judged as "leakage unqualified".

[0051] 2. Flavor compound detection After aging, a 20 mL sample was taken and the contents of guaiacol and ginkgolide B were detected by gas chromatography-mass spectrometry (GC-MS); the total contents of higher alcohols (isoamyl alcohol, isobutanol) and esters (ethyl acetate, ethyl lactate) were detected by high performance liquid chromatography (HPLC).

[0052] 3. Structural stability test Before and after aging, the diameter of the barrel at the middle (maximum diameter) is measured with a digital caliper (accuracy 0.01mm), and the deformation rate is calculated (deformation rate = (diameter after aging - diameter before aging) / diameter before aging × 100%). If the deformation rate is greater than 1%, it is judged as "structurally unstable".

[0053] 4. Aging Efficiency Test The ethyl acetate content (a key indicator of esterification reaction) in wine samples is periodically detected by HPLC. The time it takes for the ethyl acetate content to reach a stable value (fluctuation ≤5% for 30 consecutive days) is recorded, which is the "esterification cycle". The shorter the cycle, the higher the aging efficiency.

[0054] 5. Temperature and pressure stability test (Example 5 only) During the aging process, the temperature and pressure data inside the barrel are recorded through an external monitoring terminal, and the temperature and pressure fluctuation ranges within 20 months are calculated.

[0055] 6. Detection of unique active ingredients in Eucommia ulmoides During the aging process, 20 mL of wine samples were taken every 3 months and analyzed using high performance liquid chromatography (HPLC, detection conditions: C18 column (250 mm × 4.6 mm, 5 μm), mobile phase: methanol (A) - 0.1% phosphoric acid aqueous solution (B), gradient elution program: 0-5 min A = 10%, 5-20 min A linearly increases from 10% to 90%, 20-25 min A = 90%, flow rate 1.0 mL / min, column temperature 30℃, injection volume 10 μL, detection wavelength 210 nm). The contents of genipin, aucubin, and chlorogenic acid in the wine samples were determined. After the aging process was completed, the detection data from different periods were summarized to analyze the changing trends of components with aging time.

[0056] result: Table 1 Comparison of core performance between Examples 1-3 and Comparative Examples 1-5

[0057] Table 2 Comparison of flavor and efficiency in Example 4 (different carbonization levels)

[0058] *Note: Sensory scores are given by a panel of 10 professional wine tasters (out of 100), with an emphasis on aroma layers and harmony.

[0059] Table 3. Comparison of temperature and pressure stability in Example 5 (with monitoring module) and comparison of parallel groups.

[0060]

[0061] Table 4 Comparison of the content of unique active ingredients of Eucommia ulmoides in Examples 1 / 3 / 5

[0062] Example 3 showed the lowest leakage rate and deformation rate, the highest content of flavor substances (guaiacol, ginkgolide B) and esters, and the shortest esterification cycle, proving that the substrate pretreatment + controlled carbonization + gradient binding + composite sealing + activation process is an organic whole, and the absence of any key feature (such as comparative examples 2-5) will lead to a significant decrease in performance.

[0063] Compared with Comparative Example 1 (oak barrel), Example 3 showed a 43-fold increase in guaiacol content and the detection of ginkgolide B, which is absent in oak barrels. At the same time, the leakage rate and deformation rate were lower, proving that the present invention is superior to traditional oak barrels in terms of flavor uniqueness and structural stability.

[0064] Example 4 shows that the carbonization level can precisely control the flavor (phenol content) and aging efficiency (esterification cycle) to meet the aging needs of different types of baijiu.

[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A controlled carbonization-gradient binding phenolic aroma barrel made of Eucommia ulmoides wood for Baijiu (Chinese liquor), characterized in that, The system includes a barrel base layer and a primary sealing structure. The barrel base layer is a barrel-shaped structure with open ends. It is formed by splicing together Eucommia ulmoides wood boards. The raw material for the Eucommia ulmoides wood boards is Eucommia ulmoides trees aged 18-22 years with a diameter at breast height (DBH) ≥ 20 cm. The preparation process of the Eucommia ulmoides wood boards includes the following pretreatment steps: Pretreatment: Place the Eucommia ulmoides wood board in pure water at 35 kHz and 35 ℃ for ultrasonic cleaning for 150 minutes, and collect the cleaning water for later use. (1) Segmented steaming: Place the cleaned Eucommia ulmoides wood boards in a steaming device and steam them at a constant temperature of 105℃±2℃ for 3 hours; (2) Microwave degreasing: The steamed Eucommia ulmoides wood boards were irradiated with a microwave device at a frequency of 2450MHz for 120 seconds. (3) Gradient drying: The degreased Eucommia ulmoides wood boards are placed in a drying equipment, first heated at 55℃ for 12 hours, then cooled to 45℃ for 24 hours, and finally cooled to 35℃ for 12 hours. The moisture content of the dried Eucommia ulmoides wood boards is controlled at 14%±0.5%. The primary sealing structure is a mortise and tenon joint structure, which is set at both ends of the barrel base material layer to connect the circular barrel port and the barrel lid. The fitting accuracy of the mortise and tenon joint structure is ±0.05mm, and its fitting surface is the radial end face of the circular barrel port and the corresponding mating end face of the barrel lid.

2. The controllable carbonization-gradient binding phenolic aroma barrel for baijiu made from Eucommia ulmoides wood according to claim 1, characterized in that, The inner surface of the barrel substrate layer is provided with a modified layer; the modified layer is a controllable carbonized microporous layer, and the preparation process of the controllable carbonized microporous layer is as follows: the inner surface of the barrel substrate layer is subjected to graded carbonization treatment using carbonization equipment to form a carbonized layer with a thickness of 0.2mm-0.5mm on the inner surface; the specific process parameters and corresponding micropore sizes of the graded carbonization treatment are as follows: (1) Light carbonization: carbonization temperature 180℃, carbonization time 15 minutes, forming a carbonization layer with micropore size ≤50μm; (2) Moderate carbonization: carbonization temperature 220℃, carbonization time 20 minutes, forming a carbonized layer with micropore size of 80μm-120μm; (3) Deep carbonization: carbonization temperature 260℃, carbonization time 25 minutes, forming a carbonization layer with micropore size of 150μm-200μm.

3. The controllable carbonization-gradient binding phenolic aroma barrel for baijiu made from Eucommia ulmoides wood according to claim 2, characterized in that, The outer surface of the barrel base material layer, i.e. the outer wall of the circular barrel, is provided with a reinforcing layer; the reinforcing layer is a 304 stainless steel strip clamping structure, the 304 stainless steel strip has a thickness of 1.2mm and a width of 40mm; the clamping method of the 304 stainless steel strip is a non-equidistant gradient clamping, and the clamping positions are distributed along the height direction of the circular barrel. The specific clamping distance parameters are as follows: the distance between adjacent 304 stainless steel strips in the area from the barrel opening down to 1 / 3 of the barrel height is 120mm, the distance between adjacent 304 stainless steel strips in the area from 1 / 3 to 2 / 3 of the barrel height is 74mm, and the distance between adjacent 304 stainless steel strips in the area from the barrel bottom up to 1 / 3 of the barrel height is 120mm.

4. The controllable carbonization-gradient binding phenolic aroma barrel for baijiu made from Eucommia ulmoides wood according to claim 3, characterized in that, A secondary seal is provided between the tenon and mortise mating surfaces of the primary sealing structure; the secondary seal is a food-grade silicone gasket with a Shore hardness of 60±5, the gasket shape matches the shape of the tenon and mortise mating surfaces, the gasket thickness is 3mm, and the food-grade silicone gasket completely covers the tenon and mortise mating surfaces.

5. The controllable carbonization-gradient binding phenolic aroma barrel for baijiu made from Eucommia ulmoides wood according to claim 4, characterized in that, The outer sides of both ends of the circular barrel are equipped with a three-stage seal, which together with the primary and secondary seals forms a triple-layer composite sealing system. The third-stage seal is a 304 stainless steel flange, the inner diameter of which matches the outer diameter of the circular barrel's end. Bolt holes are evenly distributed along the circumference of the 304 stainless steel flange. The installation method for the 304 stainless steel flange is as follows: the 304 stainless steel flange is fitted onto the outer side of the circular barrel's end, bolts are passed through the bolt holes and tightened, applying a force of ≥25N. The preload force of m causes the 304 stainless steel flange to press tightly against the fitting part of the circular barrel body and the barrel lid.

6. The controllable carbonization-gradient phenolic aroma barrel made of Eucommia ulmoides wood for Baijiu (Chinese liquor) according to claim 5, characterized in that, The inner surface of the modified layer, i.e., the inner wall of the controllable carbonized microporous layer, is provided with a functional layer; the functional layer is an array of inner wall guiding grooves, which are uniformly distributed along the circumference of the circular barrel. The structural parameters of a single guiding groove are: groove depth 2mm, groove width 5mm, and center-line spacing between adjacent guiding grooves 8mm; the inclination angle of the guiding groove is the angle between the center line of the guiding groove and the axis of the circular barrel, which is 15°, and the guiding groove extends obliquely from the barrel opening to the barrel bottom along the height direction of the circular barrel.

7. The controllable carbonization-gradient binding phenolic aroma barrel for baijiu made from Eucommia ulmoides wood according to claim 6, characterized in that, It also includes a barrel activation process for pre-treating the inner wall of the barrel, the barrel activation process comprising the following steps: (1) Preparation of the flavoring juice: ① Take 15g of cinnamon, 25g of osmanthus, 50g of chrysanthemum and 20g of dried tangerine peel by weight and mix them to obtain a compound aromatic plant; add 50% edible alcohol to the compound aromatic plant, the total mass of the compound aromatic plant to the volume ratio of 50% edible alcohol is 1g:22mL, and soak at room temperature for 10 days. ② The residue of the compound aromatic plants after soaking is removed by filtration equipment, and the soaking liquid is collected; the soaking liquid is placed in a vacuum distillation device and distilled under vacuum conditions of 48℃ and -0.08MPa for 2.5 hours, and 450mL~550mL of distillate is collected. ③ Take the pure water used to clean the Eucommia ulmoides wood board before the segmented steaming in step (1) of claim 1 (i.e., the ultrasonic cleaning water of the Eucommia ulmoides wood board), place it in a vacuum distillation device, and distill it under vacuum for 2.5 hours at a temperature of 58℃ and a vacuum degree of -0.08MPa, and collect 0.8L to 1.2L of distillate; ④ Mix the distillate collected in step ② with the distillate collected in step ③ at a volume ratio of 2.5:1 to obtain activated aroma juice; (2) Permeation of aroma: ① Fill the activated aroma juice into the spraying device, the nozzle of the spraying device has a diameter of 0.5mm; spray the activated aroma juice evenly onto the inner wall of the barrel through the wine filling hole in the center of the round barrel lid, keeping the distance between the nozzle and the inner wall of the barrel 15cm-20cm during spraying to ensure that the activated aroma juice completely covers the inner wall of the barrel. ② Seal the wine filling hole with a perforated silicone stopper, and inject compressed air into the barrel through the hole of the perforated silicone stopper to maintain the pressure inside the barrel at 0.18MPa for 8 minutes; ③ Remove the compressed air supply system, keep the barrel sealed and let it stand for 10 days to complete the barrel activation.

8. A method for applying the controlled carbonization-gradient binding phenolic aroma barrel of Eucommia ulmoides wood for Baijiu (Chinese liquor) as described in any one of claims 1-7, characterized in that, Includes the following steps: (1) Selection of base liquor: Select light-aroma baijiu with an alcohol content of 60% vol as base liquor, and filter the base liquor with a filter membrane with a pore size of 0.45 μm to remove impurities from the base liquor; (2) Barrel filling operation: The filtered base liquor is poured into the phenolic aroma barrel through the filling hole of the round barrel lid, and the volume of the base liquor is controlled to be 95% of the internal volume of the phenolic aroma barrel, leaving 5% headspace. (3) Aging treatment: After sealing the filling hole with a perforated silicone stopper, choose any of the following aging conditions for aging: ①Ambient temperature aging: Place the phenolic aroma barrels in an environment with a temperature of 20℃-25℃ and a ventilation rate of 0.5m / s-1m / s for 7 months; ② Constant temperature aging: The phenolic aroma barrels are placed in a constant temperature aging chamber at 22℃±1℃ for 18 months, and the relative humidity of the constant temperature aging chamber is controlled at 60%-65%; ③ Long-term aging at room temperature: Place the phenolic aroma barrels in an environment with a temperature of 20℃-25℃ and a ventilation rate of 0.5m / s-1m / s for 20 months.

9. The application method according to claim 8, characterized in that, The circular lid of the phenolic aroma container also integrates a micro-oxygen exchange device and a sensor integration module. The micro-oxygen exchange device is located at the edge of the circular lid and is a one-way valve structure with a breathable membrane with a 0.22μm pore size. The micro-oxygen exchange device is used to control the oxygen exchange rate inside the container to be 0.5mL / day-1mL / day. The sensor integration module is located on the inside of the circular lid and includes a temperature sensor and a pressure sensor. The temperature sensor has a measurement range of 0℃-50℃, and the pressure sensor has a measurement range of 0MPa-0.3MPa. The sensor integration module also includes a wireless transmission unit for transmitting the data collected by the temperature sensor and pressure sensor to an external monitoring terminal in real time.

10. The controllable carbonization-gradient phenolic aroma barrel for baijiu made from Eucommia ulmoides wood according to claim 7, characterized in that, The 50-degree edible alcohol mentioned in step (1)① is of food grade purity, and the 50-degree edible alcohol is filtered through a filter membrane with a pore size of 0.22μm before use; the working pressure of the spray device mentioned in step (2)① is 0.2MPa-0.3MPa, to ensure that the activated aroma is sprayed evenly in a mist.

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