Brewing method of grape wine

Abstract

The invention relates to the technical field of wine brewing, and particularly discloses a wine brewing method which comprises the following steps: by taking cabernet sauvignon grapes as a raw material, selecting grains of the cabernet sauvignon grapes, removing stems, crushing, putting into a pottery pot, soaking for 46-50 hours at 4-6 DEG C, carrying out alcoholic fermentation at 23-25 DEG C, ending the fermentation when the specific gravity of grape fermentation liquor is 0.990-0.992, and separating peel residues to obtain the wine. By utilizing the micro-aerobic permeation effect and the natural fermentation advantage of the pottery pot, the content of total phenols, total tannin, total flavonoids and monomer phenolic substances in the wine is remarkably increased, the composition of organic acids and volatile aroma components is optimized, the wine is endowed with more complex sensory characteristics, and the wine has the advantages of rich flavor and rich flavor. The problem of homogenization caused by existing stainless steel tank and commercial yeast fermentation is effectively solved, and technical support is provided for differentiated development of the wine industry in China.

Description

Technical Field

[0001] The present invention relates to the technical field of wine brewing, and in particular to a wine brewing method. Background Art

[0002] While existing winemaking technologies have improved the fermentation process, they have also resulted in a loss of regional characteristics and typical styles. Stainless steel tanks are the most widely used tank material in modern winemaking. They offer advantages such as excellent sealing, easy cleaning and disinfection, and resistance to microbial contamination. However, their inert nature prevents interaction with the wine to generate flavor precursors, limiting the flavor potential of the resulting wine. Furthermore, the strictly anaerobic environment of stainless steel tanks can inhibit micro-oxidation, leading to the accumulation of sulfides and increased reductive properties of the wine. Summary of the Invention

[0003] To address the problem of wine flavor homogeneity caused by existing winemaking techniques, the present invention provides a wine brewing method that utilizes the micro-oxygen permeability of ceramic pots to promote slow oxidation, combined with natural fermentation to preserve the activity of native microorganisms, thereby increasing the content of phenolic substances and optimizing aroma components, resulting in a differentiated product. The wine brewed by this method significantly increases the content of acid compounds such as dodecanedioic acid, 4-acetylbenzoic acid, and 5-oxotetrahydrofuran-2-carboxylic acid; esters such as δ-tetradecalactone and diethyl succinate; as well as total phenols, total tannins, and total flavonoids. This gives the wine advantages in tannin properties (texture and astringency), taste complexity, and aftertaste persistence, resulting in a richer, fuller flavor.

[0004] The present invention provides a wine brewing method, which specifically comprises the following steps: Cabernet Sauvignon grapes are sorted, destemmed and crushed before being put into ceramic jars; Immerse at 4℃~6℃ for 46h~50h; Alcoholic fermentation is carried out at 23℃~25℃, and the tank is turned over 2~3 times a day, each time for 10 min~30 min; When the specific gravity of the grape fermentation liquid is 0.990~0.992, the fermentation is completed, and the skin and pulp are separated to obtain wine.

[0005] The present invention utilizes the micro-oxygen permeability of ceramic pots to promote slow oxidation, and combines it with natural fermentation to retain the activity of local microorganisms. The resulting wine significantly increases the characteristic flavor substances and the content of total phenols, total tannins, and total flavonoids, giving the wine advantages in terms of tannin characteristics (texture and astringency), taste complexity, and aftertaste persistence, and the flavor is richer and fuller.

[0006] Preferably, the immersion time is 48 h.

[0007] Preferably, the alcohol fermentation temperature is 24°C.

[0008] Preferably, the backflow duration is 20 minutes.

[0009] Preferably, the fermentation is terminated when the specific gravity of the grape fermentation liquid reaches 0.991.

[0010] Preferably, the grape variety is Cabernet Sauvignon from the eastern foot of Helan Mountain in Ningxia.

[0011] Preferably, the grapes are selected from grape fruits with a sugar content of 210 g / L to 270 g / L.

[0012] Preferably, the oxygen permeability of the ceramic pot is 24 cm³ / d.

[0013] Compared with the prior art, the present invention has the following beneficial effects: The present invention uses ceramic pots for winemaking, combining low-temperature maceration at 4°C to 6°C and constant-temperature fermentation at 23°C to 25°C, while retaining the activity of native microorganisms through natural fermentation. The synergistic effect of the ceramic pots and related conditions significantly increased the relative abundance of beneficial fungi in wine, with the total phenol, total tannin, and total flavonoid contents increased to 2810.67 mg / L, 2133.00 mg / L, and 1828.00 mg / L, respectively. At the same time, the contents of acid compounds such as dodecanedioic acid, 4-acetylbenzoic acid, and 5-oxotetrahydrofuran-2-carboxylic acid, and esters such as δ-tetradecaprolactone and diethyl succinate were significantly increased, forming a more complex aroma and providing a special flavor for the sensory characteristics of the wine. However, when the fermentation temperature is 20°C, it is difficult to achieve similar technical effects using the same ceramic pots. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0015] Figure 1 The relative abundance of wine fungi at different stages of natural fermentation in ceramic pots.

[0016] Figure 2 The relative abundance of wine bacteria at different stages of natural fermentation in ceramic jars.

[0017] Figure 3 The relative abundance of wine fungi at different stages of natural fermentation in stainless steel tanks.

[0018] Figure 4The relative abundance of wine bacteria at different stages of natural fermentation in stainless steel tanks.

[0019] Figure 5 To investigate the changes in the main phenolic compounds in wine during natural fermentation in ceramic and stainless steel tanks; In the figure, A is the change graph of total phenol content; B is the graph showing the changes in total tannin content; C is the change graph of total flavonoid content.

[0020] Figure 6 Multivariate statistical analysis of organic acids in wines fermented in ceramic and stainless steel tanks at different stages of natural fermentation; In the figure, A is the organic acid heat map; B is the organic acid OPLS-DA analysis score graph; C is the VIP score diagram of organic acid OPLS-DA analysis.

[0021] Figure 7 Multivariate statistical analysis of flavor compounds in wines fermented in ceramic and stainless steel tanks at different stages of natural fermentation; In the figure, A is the Venn diagram of the difference material during GR, EFP, and EFS periods; B is the VIP-FC value of differential metabolites during pottery fermentation; C is the VIP-FC value of differential metabolites during stainless steel tank fermentation; D is the VIP-FC value of the difference metabolites between ceramic pots and stainless steel pots.

[0022] Figure 8 Radar chart for sensory evaluation of naturally fermented wines in clay and stainless steel tanks. DETAILED DESCRIPTION

[0023] The specific embodiments of the present invention are described in detail below, but it should be understood that the scope of protection of the present invention is not limited by the specific embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention. The experimental methods described in the embodiments of the present invention are conventional methods unless otherwise specified, and the materials, reagents, etc. used in the following embodiments can be obtained from commercial sources unless otherwise specified.

[0024] Example 1: A wine brewing method comprising the following steps: Select grape varieties and pottery: The grape variety is Cabernet Sauvignon from the eastern foot of Helan Mountain in Ningxia; the pottery is produced by Chongqing Rongchang District Chengjing Ceramics Co., Ltd., with a capacity of 1000 L and an oxygen permeability of 24 cm 3 / d.

[0025] Fermentation: Grapes with a sugar content of 240 g / L were picked, sorted, and de-leaved and de-stemmed. After being crushed, the grapes were placed in ceramic pots that had been washed with alkali and citric acid. After being immersed at 4°C for 48 hours, alcohol fermentation was carried out at 24°C.

[0026] Monitoring: Monitor temperature and specific gravity changes every morning and evening, and invert the tank twice a day, each time for 20 minutes.

[0027] Obtaining wine: Fermentation is complete when the specific gravity of the grape fermentation liquid reaches 0.991. After standing and separating the skins and residues, wine is obtained. The specific gravity is the ratio of the density of the grape fermentation liquid to the density of water at 4°C. In this embodiment, the density of the grape fermentation liquid is 991 kg / m 3 , the density of water at 4°C is 1000 kg / m 3 , so the specific gravity is 0.991.

[0028] Example 2: A method for brewing wine, comprising the following steps: A wine brewing method comprising the following steps: Select grape varieties and pottery: The grape variety is Cabernet Sauvignon from the eastern foot of Helan Mountain in Ningxia; the pottery is produced by Chongqing Rongchang District Chengjing Ceramics Co., Ltd., with a capacity of 1000 L and an oxygen permeability of 24 cm 3 / d.

[0029] Fermentation: Grapes with a sugar content of 210 g / L were picked, sorted, and de-leaved and de-stemmed. After being crushed, the grapes were placed in ceramic pots that had been washed with alkali and citric acid. After being immersed at 5°C for 46 hours, alcohol fermentation was carried out at 23°C.

[0030] Monitoring: Monitor temperature and specific gravity changes every morning and evening, and invert the tank twice a day, each time for 10 minutes.

[0031] Obtaining wine: The fermentation is completed when the specific gravity of the grape fermentation liquid is 0.990, and the wine is obtained after standing and separating the skin and residue. In this embodiment, the density of the grape fermentation liquid is 990 kg / m 3 , the density of water at 4°C is 1000 kg / m 3 , so the specific gravity is 0.990.

[0032] Example 3: A wine brewing method comprising the following steps: A wine brewing method comprising the following steps: Select grape varieties and pottery: The grape variety is Cabernet Sauvignon from the eastern foot of Helan Mountain in Ningxia; the pottery is produced by Chongqing Rongchang District Chengjing Ceramics Co., Ltd., with a capacity of 1000 L and an oxygen permeability of 24 cm 3 / d.

[0033] Fermentation: Grapes with a sugar content of 270 g / L were picked, sorted, and de-leaved and de-stemmed. After being crushed, the grapes were placed in ceramic pots that had been washed with alkali and citric acid. After being immersed at 6°C for 50 hours, alcohol fermentation was carried out at 25°C.

[0034] Monitoring: Monitor temperature and specific gravity changes every morning and evening, and invert the tank three times a day, each time for 30 minutes.

[0035] Obtaining wine: The fermentation is completed when the specific gravity of the grape fermentation liquid is 0.992, and the wine is obtained after standing and separating the skin and residue. In this embodiment, the density of the grape fermentation liquid is 992 kg / m 3 , the density of water at 4°C is 1000 kg / m 3 , so the specific gravity is 0.992.

[0036] Comparative Example 1 This comparative example is consistent with other methods of Example 1, except that a stainless steel tank is used: The grape variety used was Cabernet Sauvignon from the eastern foot of the Helan Mountains in Ningxia. Grapes with a sugar content of 240 g / L were picked and sorted, and the leaves and stems were removed. After crushing, the grapes were placed in stainless steel tanks that had been washed with alkali and citric acid. After maceration at 4°C for 48 hours, alcohol fermentation was carried out at 24°C. Temperature and specific gravity changes were monitored every morning and evening. The tanks were inverted twice a day, each time for 20 minutes. The specific gravity of the grape fermentation liquid was 0.991 (the density of the grape fermentation liquid is 991 kg / m 3 ) when the fermentation is over, and the wine is obtained after standing and separating the skins and residues.

[0037] The wines prepared in Examples 1 to 3 of the present invention had similar properties. Using Example 1 and Comparative Example 1 as examples, the present invention tested the wine's bacterial diversity, basic physical and chemical parameters, content of major phenolic substances, content of monomeric phenols, organic acids, and volatile aroma components at five stages during the wine preparation process, and conducted sensory evaluations. The five stages were: grape juice tank entry, early natural fermentation, mid-fermentation, late fermentation, and final fermentation.

[0038] 1. Sampling information for wines fermented in ceramic and stainless steel tanks at different stages The sampling information of ceramic jars and stainless steel tanks at different fermentation stages is shown in Table 1.

[0039] Table 1 Sampling information table 2. Analysis of bacterial diversity in ceramic and stainless steel tank wines at different fermentation stages Nucleic acid was extracted using the Qiagen DNeasy Plant Mini Kit according to the instructions. DNA quality was tested by 1.2% agarose gel electrophoresis, and the extracted DNA was quantified.

[0040] The amplification conditions of the bacterial 16S region were as follows: pre-denaturation at 98°C for 5 min, denaturation at 98°C for 30 s, annealing at 52°C for 30 s, extension at 72°C for 45 s, 25 cycles, extension at 72°C for another 5 min, and finally insulation at 12°C.

[0041] The fungal ITS region amplification conditions were as follows: 95°C pre-denaturation for 5 minutes, 95°C denaturation for 1 minute, 55°C annealing for 30 seconds, and 72°C extension for 1 minute. After 30 cycles, the amplified product was extended at 72°C for 10 minutes. The amplified product was analyzed by 1.2% agarose gel electrophoresis and recovered by magnetic bead purification.

[0042] PCR amplification products were quantified using the Quant-iT PicoGreen dsDNA Assay Kit and mixed according to the desired ratio. Sequencing libraries were prepared using the TruSeq Nano DNA LT Library Prep Kit. The libraries were quality-checked and quantified using the Agilent High Sensitivity DNA Kit and the Quant-iT PicoGreen dsDNA Assay Kit, respectively, before paired-end sequencing using a MiSeq sequencer.

[0043] According to the above experimental results (see Figures 1 to 4 ), bacteria that decompose pectin, such as Tatumella, have an advantage in the fermentation of clay pots, increasing the content of fermentable sugars; the relative abundance of beneficial fungi such as Saturnispora and Metschnikowia in clay pots during the BF period is significantly higher than that in stainless steel tanks, and they can metabolize to produce esters, higher alcohols and thiol compounds, thereby improving the flavor and quality of the product.

[0044] 3. Analysis of basic physical and chemical indicators of wine obtained from ceramic jars and stainless steel tanks The reducing sugar, total acid, ethanol, SO2 and volatile acid contents in wine were measured according to the national standard GB 15038-2006 “General analytical methods for wine and fruit wine”; the pH value was measured with a pH meter. The results are shown in Table 2.

[0045] Table 2 Basic physical and chemical indicators of naturally fermented Cabernet Sauvignon wine Note: Different lowercase letters in the same column indicate significant differences (P<0.05).

[0046] The above data show that wines from both the EFP and EFS periods meet the national standard GB 15038-2006, with no significant difference in alcohol content. The pH value of wines from the EFP period was significantly higher than that from the EFS period (P<0.05).

[0047] 4. Analysis of the content of main phenolic substances in ceramic and stainless steel tank wines at different fermentation stages (1) Determination of total phenol content: Folin-phenol method was used. After diluting the wine sample 10 times, 1 mL was taken into a 100 mL volumetric flask. 60 mL of distilled water, 5 mL of Folin-phenol reagent, and 15 mL of 20% sodium carbonate solution were added in sequence. The OD value was measured after the solution was fixed to volume and allowed to stand for 2 h. 765 Gallic acid standard curve: Prepare 5 mg / mL gallic acid standard solution, take 1 mL of gallic acid standard solution with different concentrations of 0, 50, 100, 150, 200, 250, and 300 mg / L in a 100 mL volumetric flask, repeat the above determination steps, and measure the OD 765 , draw a standard curve. Combined with the standard curve, the corresponding total phenol content was found and the determination was repeated 3 times. The results were calculated as gallic acid.

[0048] (2) Determination of total tannin content: Folin-Denis method was used. 1 mL of wine was placed in a 100 mL volumetric flask, and 0.5 mL of FoLin-Denis reagent and 1 mL of saturated sodium carbonate solution were added. The OD value was measured after the flask was fixed to volume and allowed to stand for 30 minutes. 650 Tannic acid standard curve: Prepare 1 mg / mL tannic acid standard solution, pipette 0, 2, 4, 6, 8, 10 mL of the standard solution into a 100 mL volumetric flask, repeat the above determination steps, and measure the OD 650 , draw a standard curve. Combined with the standard curve, find the corresponding total tannin content, repeat the measurement three times, and calculate the result as tannic acid.

[0049] (3) Determination of total flavonoid content: Direct colorimetric method was used. Take 1 mL of wine sample, dilute to 10 mL with methanol, add 27 mL of 30% methanol solution, 2 mL of 0.5 mol / L sodium nitrite solution, and 2 mL of 0.3 mol / L aluminum chloride solution, respectively. After standing for 5 minutes, add 10 mL of 1 mol / L sodium hydroxide solution and measure the OD value after standing for 10 minutes. 510 Rutin methanol standard curve: Prepare 1 mg / mL rutin methanol standard solution. Take 0, 1, 2, 3, 4, 5, and 6 mL of the standard solution and dilute to 10 mL with methanol. Repeat the above determination operation and measure the absorbance OD 510 The standard curve was prepared. The corresponding total flavonoid concentration was obtained by combining the standard curve and repeated three times. The results were calculated as rutin.

[0050] The results of the analysis showed that (see Figure 5During fermentation in clay pots, the levels of total phenols, total tannins, and total flavonoids were significantly higher than those in stainless steel pots (P<0.05). At the end of fermentation, the total phenols, total tannins, and total flavonoids in the clay pot wines were 2810.67 mg / L, 2133.00 mg / L, and 1828.00 mg / L, respectively, significantly higher than those in stainless steel pots (2105.00 mg / L, 1883.67 mg / L, and 1628.00 mg / L). Therefore, it is speculated that clay pot fermentation promotes the dissolution, formation, and accumulation of total phenols, total tannins, and total flavonoids in wine.

[0051] 5. Analysis of the content of main monomer phenolic compounds in ceramic and stainless steel tank wines at different fermentation stages Take 1 mL of wine sample and add 0.5 mL of 80% methanol aqueous solution (containing 0.2% vitamin C), vortex mix, ultrasonically extract at room temperature for 30 min, centrifuge at 12000 rpm for 10 min, take the supernatant, repeat the extraction twice, mix the extract and dilute it 5 times before testing on the instrument.

[0052] Table 3 Compound contents of Cabernet Sauvignon wine under different fermentation tank treatments Note: Different lowercase letters in the same row indicate significant differences ( P <0.05).

[0053] Chromatographic conditions: Waters HSS T3 (50 × 2.1 mm, 1.8 μm); mobile phase: ultrapure water (containing 0.1% formic acid) in phase A, acetonitrile (containing 0.1% formic acid) in phase B; flow rate: 0.3 mL / min; column temperature: 40°C; injection volume: 2 μL; elution gradient: A / B (90:10, v / v) at 0 min, A / B (90:10, v / v) at 2 min, A / B (40:60, v / v) at 6 min, A / B (40:60, v / v) at 9 min, A / B (90:10, v / v) at 9.1 min, and A / B (90:10, v / v) at 12 min. Mass spectrometry: equipped with an electrospray ionization (ESI) source, ion spray voltage: −2800 V, temperature: 350°C, and ion transfer tube temperature: 320°C. The scanning mode was Full Scan-ddMS2, with negative ion scanning. The primary mass spectrometer scan range (m / z) was 100–900. Qualitative analysis was based on the precise molecular masses of the compounds determined by high-resolution mass spectrometry; absolute quantitative analysis was performed using peak area and external standard.

[0054] According to the above experimental results (see Table 3), the total monomeric phenolic content in the clay pot wine was significantly higher than that in the stainless steel pot (P < 0.05). Meanwhile, only rutin and syringic acid were significantly lower in the clay pot wine than in the stainless steel pot (P < 0.05), while the remaining monomeric phenolic contents were significantly higher than those in the stainless steel pot (P < 0.05). Therefore, naturally fermented Cabernet Sauvignon wine in clay pots is more conducive to the production and accumulation of monomeric phenolic compounds. Notably, resveratrol, a natural antioxidant that may play a key role in the prevention and treatment of chronic diseases, was only present during the EFP period and was not detected during the EFS period.

[0055] VI. Analysis of organic acids and volatile aroma components of wines fermented in ceramic and stainless steel tanks at different stages (1) Determination of organic acid content: Take 2 mL of wine sample and add 0.5 mL of 70% methanol, vortex for 5 min, centrifuge at 12000 r / min at 4℃ for 10 min, take the supernatant and let it stand at -20℃ for 30 min, centrifuge at 12000 r / min at 4℃ for 10 min, take the supernatant and pass it through a protein precipitation plate and store it at -20℃ for testing.

[0056] Chromatographic conditions: Column: ACQUITY HSS T3 (1.8 µm, 100 mm × 2.1 mm); Mobile phase A: ultrapure water (0.05% formic acid), Mobile phase B: acetonitrile (0.05% formic acid); Gradient elution: A / B (95:5, v / v) at 0 min, A / B (5:95, v / v) at 8–9.5 min, A / B (95:5, v / v) at 9.6–12 min; Flow rate: 0.35 mL / min, Column temperature: 40°C, Injection volume: 2 μL. Mass spectrometry conditions: Electrospray temperature: 550°C, Mass spectrometer voltage: 5500 V in positive ion mode, -4500 V in negative ion mode, Curtain gas (CUR) at 35 psi. Qualitative analysis was performed using a Metware Database (MWDB) constructed based on standards, and quantitative analysis was performed using external standard peak area.

[0057] The results (Table 4) indicate that nine organic acids were present in both EFP and EFS wines. The total organic acid content in EFP wines was significantly higher than in EFS wines (P < 0.05), approximately 1.5 times that of EFS wines. This suggests that wines fermented in ceramic vats contain higher organic acid content than wines fermented in stainless steel vats. Lactic acid, gallic acid, and shikimic acid contents were significantly higher in EFP wines than in EFS wines (P < 0.05), suggesting that fermenting wine in ceramic vats may be more conducive to the accumulation of lactic acid, shikimic acid, and gallic acid. Notably, the contents of caffeic acid and cinnamic acid showed significant differences between ceramic and stainless steel wines. Specifically, caffeic acid content increased significantly in EFP wines and decreased in EFS wines. Conversely, cinnamic acid content increased significantly in EFS wines and decreased to zero in EFP wines. This suggests that ceramic wines may favor the accumulation of caffeic acid, while stainless steel wines may promote the accumulation of cinnamic acid. Although both caffeic acid and cinnamic acid show significant antioxidant activity, caffeic acid can combine with anthocyanins to form a stable complex, thereby enhancing its color stability and extending the color life of the wine.

[0058] Table 4 Organic acid content of naturally fermented Cabernet Sauvignon wine Multivariate statistical analysis found that (see Figure 6 ), the samples can be divided into three categories through cluster analysis. According to the VIP value of each substance, shikimic acid, gallic acid, lactic acid, and succinic acid are the four types of substances that contribute the most to organic acids (VIP value>1).

[0059] (2) Determination of volatile aroma components: Take 2 mL of sample in a headspace vial and add 1 g of NaCl and 500 ng of internal standard 2-methyl-3-heptanone.

[0060] Chromatographic conditions: Column: DB-wax (30 m × 0.25 mm × 0.25 µm); Temperature program: Initial temperature: 50°C, hold for 4 min, then increase to 230°C at 5°C / min, hold for 5 min; Carrier gas (He) flow rate: 1.0 mL / min; Split ratio: 10:1. Mass spectrometry conditions: Electron ionization source; Electron energy: 70 eV; Transfer line temperature: 230°C; Ion source temperature: 230°C; Precursor ion: m / z 285; Activation voltage: 1.5 V; Mass scan range: m / z 33–550. Qualitative analysis of aroma compounds was performed using the NIST 2017 spectral library, and semi-quantitative analysis was performed using 2-methyl-3-heptanone as an internal standard.

[0061] The above test results show that (see Figure 7), only 11 of the 57 volatile aroma components detected were shared by the GR, EFP, and EFS stages, indicating significant changes in ester aroma and glycerol-derived substances during Cabernet Sauvignon's alcoholic fermentation process. Comparisons between clay pots and stainless steel pots revealed that the overall concentration of differential flavor compounds in the EFP stage was higher than that in the EFS stage. Specifically, the levels of acids such as dodecanedioic acid, 4-acetylbenzoic acid, and 5-oxotetrahydrofuran-2-carboxylic acid, as well as esters such as δ-tetradecaprolactone and diethyl succinate, were significantly higher in the EFS stage. These characteristic flavor compounds contribute to the coconut, caramel, and fruity aromas of clay pot-fermented wines.

[0062] 7. Sensory Evaluation of Wine in Ceramic Jars and Stainless Steel Tanks Ten food science graduate students (five men and five women) who had been trained and employed were selected to conduct a sensory analysis of the wines using a consensus-based descriptive method, focusing on appearance (transparency and color), aroma (intensity, elegance and refinement, complexity and extension), taste (structure balance, body, tannin texture and astringency, complexity, and aftertaste), and overall judgment.

[0063] The results of the analysis showed that (see Figure 8 ), wines fermented in pottery have advantages in tannin characteristics (texture and astringency), taste complexity and aftertaste persistence, with a richer and fuller flavor and more distinctive aroma intensity.

[0064] Although preferred embodiments of the present invention have been described, additional changes and modifications to these embodiments may occur to those skilled in the art once the basic inventive concepts become known.

[0065] Obviously, those skilled in the art may make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if such modifications and variations fall within the scope of the claims and their equivalents, the present invention is intended to include such modifications and variations.

Claims

1. A wine brewing method, characterized in that: The specific steps include: The grapes are sorted, destemmed and crushed before being put into clay pots; Immerse at 4℃~6℃ for 46h~50h; Alcoholic fermentation is carried out at 23℃~25℃, and the tank is turned over 2~3 times a day, each time for 10 min~30 min; When the specific gravity of the grape fermentation liquid is 0.990~0.992, the fermentation is completed, and the skin and pulp are separated to obtain wine.

2. The wine brewing method according to claim 1, characterized in that: The immersion time is 48 h.

3. The wine brewing method according to claim 1, characterized in that: The alcohol fermentation temperature is 24°C.

4. The wine brewing method according to claim 1, characterized in that: The tank pouring time is 20 minutes.

5. The wine brewing method according to claim 1, characterized in that: The fermentation is completed when the specific gravity of the grape fermentation liquid reaches 0.

991.

6. The wine brewing method according to claim 1, characterized in that: The grape variety is Cabernet Sauvignon from the eastern foot of Helan Mountain in Ningxia.

7. The wine brewing method according to claim 1, characterized in that: The grapes are selected to have a sugar content of 210 g / L to 270 g / L.

8. The wine brewing method according to claim 1, characterized in that: The oxygen permeability of the ceramic pot is 24 cm³ / d.

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