Brewing process of high-degree brandy brewed by late-autumn yellow pears

Abstract

The invention discloses a brewing process of high-degree brandy brewed by late-autumn yellow pears, which comprises the following process steps of: preparing for the first time: adding raw materials according to the proportion that every 100 jin of pear pulp is matched with 15-20 jin of purified water and 5 jin of white granulated sugar, uniformly stirring, adding fruit koji, and fermenting in a jar; during fermentation, a stirring device is adopted for stirring treatment, 0.2-0.4% of rhizopus koji is added after 1-3 hours, and the pH value is adjusted to 4.0-4.5; after 40 minutes to 2 hours, 0.3 to 0.4 percent of fragrant yeast is added, and the container is sealed; and adding 5-6% of white granulated sugar after 72-96 hours. According to the invention, the nutrient substances are effectively reserved, and the nutrient components are ensured to be blended into the wine to the greatest extent through micro-aerobic regulation and control fermentation and special distillation and ageing processes. In the brewing process of the pear pulp liquor, vinasse is recycled for multiple times, so that nutritional ingredients in the raw materials are fully extracted and converted, and the utilization rate of the raw materials is increased.

Description

Technical Field

[0001] This invention relates to the field of brewing technology, and in particular to a brewing process for high-proof brandy made from late autumn yellow pears. Background Technology

[0002] Late Autumn Yellow Pear is rich in various trace elements and amino acids, holding an important position in the fruit industry. This variety boasts a unique flavor, emitting a delicate fruity aroma, and is rich in nutrients and of excellent quality. It also possesses expectorant and cough-relieving effects, making it highly popular with consumers in both domestic and international markets.

[0003] In terms of processing and utilization, besides fresh consumption, late-autumn yellow pears are widely used in the production of juice and wine. However, most current yellow pear wine products have a relatively low alcohol content, making it difficult to meet the needs of consumers who prefer higher-proof spirits. Traditional brandy is mostly made from grapes and other raw materials. With the diversification of consumer demands for alcoholic beverage flavors, the production of brandy from pear pulp is gradually gaining attention. However, existing pear pulp brandy production methods have some shortcomings, such as the need for improvement in flavor blending, taste optimization, and raw material utilization efficiency. Some production processes fail to fully utilize the natural fruit aroma of pear pulp, resulting in a less than ideal blend of fruit and alcohol aromas in the produced brandy, and a less smooth and sweet taste. At the same time, the low efficiency of multiple uses of the raw material leads to a certain degree of resource waste. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a high-proof brandy brewing process using late autumn yellow pears.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A process for producing high-proof brandy from late autumn yellow pineapples includes the following steps:

[0007] S1. First Preparation: Add raw materials according to the ratio of 15-20 catties of purified water and 5 catties of white sugar per 100 catties of pear pulp. After stirring evenly, add fruit koji and ferment in a vat. During fermentation, use a stirring device to stir the mixture. After 1-3 hours, add 0.2-0.4% Rhizopus koji and adjust the pH to 4.0-4.5. After 40 minutes to 2 hours, add 0.3-0.4% aromatic koji and seal the container. After 72-96 hours, add 5-6% white sugar and heat to 30-35℃ and maintain for 1-2 hours. After 20-25 minutes, seal the vat. After 45 days, distill and take 5% of the alcohol for blending. Collect the lees for the second preparation.

[0008] S2. Second preparation: Add the lees, pear pulp, white sugar, and fruit koji from the first preparation in a ratio of 30:70:5:0.3. After pretreatment of the lees, put them into a vat. After 1-3 hours, add 0.2-0.4% Rhizopus koji. After 40 minutes to 2 hours, add 0.3-0.4% aromatic koji. In the fourth step, after 72-96 hours, add 5-6% white sugar. After 20-25 minutes, seal the vat. After 45 days, put it into a distillation pot. Take out 10% of the liquor for later blending. Take out the lees from the distillation pot for the third preparation process.

[0009] S3. Third preparation: Pear pulp, second preparation lees, white sugar, and fruit koji are added in a ratio of 50:50:5:0.2-0.3. After being placed in a vat, the mixture is protected from light. After 1 hour, 0.2% Rhizopus koji is added. After another 1 hour, 0.2% aromatic koji is added. After 72 hours, white sugar is added at 5-6%. The vat is sealed after 20-25 minutes. After 45 days, the mixture is transferred to a distillation pot, and 100% of the alcohol is taken out for later blending.

[0010] S4. Fourth preparation: Store for three to five years, then blend the finished wine according to the specified proportions.

[0011] Preferably, the pear pulp preparation method is as follows: Select high-quality late autumn yellow pears, wash, remove the cores, cut into pieces, and freeze at -5℃ to -10℃ for 12-24 hours. After juicing, clarify the pear juice using the gelatin-tannin method. During the clarification process, add 2-3g of gelatin and 1-2g of tannin per 100L of pear juice. First, dissolve the gelatin in warm water, and then dissolve the tannin in a small amount of alcohol before adding it to the pear juice. Stir well and let it stand for 6-8 hours.

[0012] Preferably, during the fermentation process of each preparation process, the micro-oxygen supply is 0.5-1.0 liters / hour for the first 5-7 days, the micro-oxygen supply is stopped for the middle 7-10 days, and the micro-oxygen supply is 0.2-0.5 liters / hour for the last 3-5 days. When the sugar content in the fermentation broth drops to 5-8°Bx, pretreated fresh pear juice is continuously added, and the addition rate is controlled at 1%-3% of the fermentation broth volume per hour. At the same time, every 12-24 hours, the material is added in batches at a ratio of 0.5-1g of white sugar per liter of fermentation broth.

[0013] Preferably, during the distillation process of each preparation process, the pressure of vacuum distillation is controlled at 0.05-0.08 MPa, the temperature is 60-70℃, the rectification reflux ratio is controlled at 5-8, and the distillate with an alcohol content of 40%-60% vol is collected; at the same time, a combination of atmospheric distillation and fractional distillation is adopted. First, atmospheric distillation is carried out to collect the initial fraction with an alcohol content of 30%-50% vol. When the alcohol content drops below 30% vol, the distillation temperature and condensation conditions are adjusted to collect the secondary fraction with an alcohol content of 10%-30% vol. The initial fraction and the secondary fraction are mixed and blended according to different proportions.

[0014] Preferably, in the fourth preparation process, the wine is placed in oak barrels and sprayed with distilled water that has been soaked and filtered through oak chips every 1-2 weeks, at a rate of 0.5-1 liter per square meter, and left to stand for 2-3 days.

[0015] Preferably, the oak barrel for holding the wine adopts a double-barrel structure consisting of an inner barrel and an outer barrel. The inner barrel is a conventional cylindrical shape for holding the wine, and the outer barrel is elliptical with its major axis coinciding with the central axis of the inner barrel's cylinder. A gap is left between the inner and outer barrels to form an air insulation layer. The height of the inner barrel can be 60-120cm and its diameter can be 30-60cm. The major axis of the elliptical outer barrel is 10-20cm longer than the diameter of the inner barrel, and the minor axis is 6-12cm longer than the diameter of the inner barrel. The thickness of the air insulation layer between the inner and outer barrels is 3-8cm.

[0016] Preferably, an appropriate amount of oak chips are suspended in the inner barrel containing the wine. The oak chips are thin slices made of the same material as the oak barrel and have been toasted. 200-300 grams of oak chips are suspended for every 50 liters of wine.

[0017] A high-proof brandy produced using the aforementioned late autumn yellow pear brewing process.

[0018] The present invention has the following beneficial effects:

[0019] 1. Late autumn yellow pears are selected as the core raw material, rich in various trace elements, amino acids, minerals, and other nutrients. In the production of pear juice brandy, the low-temperature freezing and gelatin-tannin clarification processes during raw material handling not only effectively preserve these nutrients but also ensure maximum infusion of nutrients into the liquor through micro-oxygen-controlled fermentation, special distillation, and aging processes. During the brewing process of pear juice brandy, the lees are recycled multiple times, allowing for the full extraction and transformation of nutrients in the raw materials, improving raw material utilization, and providing consumers with a nutrient-rich liquor.

[0020] 2. This invention, in the production of pear juice brandy, utilizes segmented fermentation and micro-oxygen regulation, continuous feeding, and precise control of distillation parameters, such as coupled vacuum distillation and rectification technology, and segmented distillation and blending at atmospheric pressure, to stably increase the alcohol content to 40%-60% vol, meeting market demand for high-proof fruit wines. Pear juice liquor, through multiple preparations and distillations, can also achieve a high alcohol content, expanding the product range of fruit wines.

[0021] 3. In the production of pear brandy, the special structure of the oak barrels and aging processes, such as the air insulation layer of the double-barrel structure, the regular spraying of distilled water filtered through oak chips, and the hanging of oak chips, add a unique oak flavor to the liquor while preserving the natural fruit aroma of the pear. This allows the fruit and liquor aromas to blend perfectly, resulting in a smoother and sweeter taste. Similarly, in the production of pear-flavored baijiu, the addition of different yeasts at different stages and the multiple fermentations of lees and new raw materials during the preparation process give the baijiu a rich complexity and unique flavor. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of a high-proof brandy brewing process using late autumn yellow pears, as proposed in this invention.

[0023] Figure 2 The sensory score variation surface diagram of the wine prepared by adjusting the alcohol content of the first and second fractions in this invention;

[0024] Figure 3 This is a line graph showing the changes in various nutritional components of the wine prepared according to the present invention at 40-60% vol.

[0025] Figure 4 The sensory score change curve of the wine obtained by adjusting the oxygenation rate in the first 5-7 days and the oxygenation rate in the last 3-5 days is shown in the present invention.

[0026] Figure 5 Line graph showing the changes in nutritional components in the wine obtained by adjusting the number of cycles in the process according to the present invention. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0028] Example 1

[0029] (I) Preparation of pear pulp

[0030] Select high-quality late autumn yellow pears, wash and core them, then cut them into small pieces and freeze them at -8℃ for 20 hours to fully break down the pear cell structure. After freezing, juice them to obtain pear juice. Add 2.5g of gelatin and 1.5g of tannin to every 100L of pear juice for clarification. First, dissolve the gelatin in warm water, and dissolve the tannin in a small amount of alcohol before adding it to the pear juice. Stir well and let it stand for 7 hours to remove impurities while effectively preserving the polyphenols, minerals, and other nutrients in the pear juice.

[0031] (II) First Preparation

[0032] Add the raw materials according to the ratio of 17 catties of purified water and 5 catties of white sugar per 100 catties of pear pulp, stir evenly, and then add fruit koji into the fermentation tank. During the first 1.5 hours of fermentation, stir the mixture using a stirring device, then add 0.3% Rhizopus koji to adjust the pH to 4.3; one hour later, add 0.35% aromatic koji and seal the container. For the first 6 days of fermentation, the micro-aerobic supply is controlled at 0.8 L / hour to promote yeast growth and flavor compound formation; for the middle 8 days, micro-aerobic supply is stopped to allow fermentation to proceed steadily; for the last 4 days, the micro-aerobic supply is adjusted to 0.3 L / hour. When the sugar content in the fermentation liquid drops to 6.5°Bx, start continuously adding pretreated fresh pear juice at a rate controlled at 2% of the fermentation liquid volume per hour. Simultaneously, every 18 hours, add white sugar in batches at a ratio of 0.7 g per liter of fermentation liquid to maintain yeast activity, ensure the sugar is fully converted into alcohol, and preserve the pear's fruity aroma. Add 5.5% white sugar after 72 hours, heat to 32℃ and maintain for 1.5 hours; seal the container after 22 minutes, and distill after 45 days.

[0033] Distillation employs a coupled process of vacuum distillation and rectification, with pressure controlled at 0.06 MPa, temperature at 65℃, and a rectification reflux ratio controlled at 6.5, collecting the distillate with an alcohol content of 40%-60% vol. Simultaneously, a combination of atmospheric distillation and fractional distillation is used. First, atmospheric distillation is performed, collecting the initial fraction with an alcohol content of 30%-50% vol. When the alcohol content drops below 30% vol, the distillation temperature and condensation conditions are adjusted to collect the secondary fraction with an alcohol content of 10%-30% vol. The initial and secondary fractions are blended in different proportions to minimize the damage of heat-sensitive components caused by high temperatures and efficiently preserve nutrients and flavor. 5% of the spirit is used for blending, and the lees are collected for a second preparation.

[0034] (III) Second preparation

[0035] Add the first-prepared lees, pear pulp, white sugar, and fruit koji in a ratio of 25:75:5:0.3. After pretreatment of the lees, place them in a vat. After 1.5 hours, add 0.3% Rhizopus koji, after 1 hour, add 0.35% aromatic koji, and after 72 hours, add 5.5% white sugar. Seal the vat after 22 minutes. After 45 days, transfer to a distillation pot. Take out 10% of the alcohol for later blending. Remove the lees from the distillation pot for use in the third preparation process. Fermentation and distillation conditions are the same as the first preparation.

[0036] (iv) Third preparation

[0037] Add pear pulp, the second batch of prepared distiller's grains, white sugar, and fruit koji in a ratio of 45:55:5:0.25. After placing the mixture in a vat, protect it from light. After one hour, add 0.2% Rhizopus koji, followed by 0.2% aromatic koji one hour later. After 72 hours, add 5.5% white sugar. Seal the vat after 22 minutes. After 45 days, transfer the mixture to a distillation pot. All the spirits are then used for later blending. Fermentation and distillation conditions are the same as the first preparation.

[0038] (v) Fourth preparation

[0039] The spirit is placed in a double-barrel oak barrel structure consisting of an inner and outer barrel. The inner barrel is a standard cylindrical shape, 90cm high and 45cm in diameter. The outer barrel is elliptical, with its major axis coinciding with the central axis of the inner barrel's cylinder. The major axis of the outer barrel is 15cm longer than the inner barrel's diameter, and its minor axis is 9cm longer. A 5cm thick air gap is left between the inner and outer barrels to form an air insulation layer. Every 10 days, 0.75 liters of distilled water filtered after being soaked in oak chips is sprayed on the surface, and the mixture is left to stand for 2.5 days. Simultaneously, an appropriate amount of oak chips is suspended in the inner barrel, 250 grams of toasted chips of the same material as the oak barrel for every 50 liters of spirit. After four years of aging, the finished spirit is blended according to a specific ratio.

[0040] Example 2

[0041] (I) Preparation of pear pulp

[0042] Select smooth-skinned, disease-free late-autumn yellow pears, rinse them thoroughly under running water, remove the cores, and cut them into 2-3 cm pieces. Place them in a -9℃ freezer for 22 hours. After freezing, juice the pears. Then, add 2.3g of gelatin and 1.4g of tannin per 100L of pear juice. Dissolve the gelatin in 40℃ warm water and the tannin in 75% alcohol, then add these to the pear juice. Stir thoroughly and let it stand for 7.5 hours to clarify the pear juice, effectively preserving its nutrients.

[0043] (II) First Preparation

[0044] The raw materials were mixed thoroughly with 16.5 catties of purified water and 5 catties of white sugar per 100 catties of pear pulp. Fruit koji was then added before fermentation in a vat. After 1.8 hours of fermentation, 0.28% Rhizopus koji was added, and the pH was adjusted to 4.25. After 1.2 hours, 0.33% aromatic koji was added, and the container was sealed. For the first 5.8 days of fermentation, the micro-aerobic supply was maintained at 0.75 L / h; for the next 8.5 days, micro-aerobic supply was stopped; and for the last 3.8 days, the micro-aerobic supply was adjusted to 0.28 L / h. When the sugar content in the fermentation liquid decreased to 6.2°Bx, pretreated fresh pear juice was continuously added at a rate of 1.8% of the fermentation liquid volume per hour. Simultaneously, every 16 hours, 0.65 g of white sugar was added in batches per liter of fermentation liquid. After 80 hours of fermentation, add 5.3% white sugar, heat to 31.5℃ and maintain for 1.4 hours; seal the tank after 21.5 minutes, and distill after 45 days.

[0045] Distillation was performed using a combination of vacuum distillation and rectification, with the pressure controlled at 0.058 MPa, the temperature set at 63.5℃, and the rectification reflux ratio at 6.2. Distillates with an alcohol content of 40%-60% vol were collected. Simultaneously, atmospheric distillation and fractional distillation were combined. First, atmospheric distillation was performed to collect the initial fraction of 30%-50% vol. When the alcohol content dropped below 30% vol, the distillation conditions were adjusted to collect the secondary fraction of 10%-30% vol. The different fractions were then blended in specific proportions. 5% of the resulting spirit was used for blending, and the lees were collected for a second preparation.

[0046] (III) Second preparation

[0047] The first batch of distiller's grains, pear pulp, white sugar, and fruit koji were added to a vat in a ratio of 27:73:5:0.3. After pretreatment of the distiller's grains, 0.28% Rhizopus koji was added after 1.8 hours, followed by 0.33% aromatic koji after 1.2 hours, and 5.3% white sugar after 80 hours. The vat was sealed after 21.5 minutes, and the liquor was distilled after 45 days. 10% of the liquor was used for later blending, and the remaining distiller's grains were used for the third batch. The fermentation and distillation conditions were the same as for the first batch.

[0048] (iv) Third preparation

[0049] Pear pulp, the second batch of prepared distiller's grains, white sugar, and fruit koji were mixed in a ratio of 47:53:5:0.24. After being placed in a vat, the mixture was kept in the dark. 0.2% Rhizopus koji was added within one hour, followed by 0.2% aromatic koji one hour later. White sugar was added at 5.3% after 72 hours. The vat was sealed after 21.5 minutes, and after 45 days, the mixture was transferred to a distillation still. All the distillate was then used for later blending. Fermentation and distillation conditions were the same as in the first preparation.

[0050] (v) Fourth preparation

[0051] The spirit is poured into double-barreled oak barrels. The inner barrel is 105cm high and 52cm in diameter. The outer barrel, an ellipse, has a major axis 16cm larger than the inner barrel's diameter and a minor axis 10cm larger. The air insulation layer is 6.5cm thick. Every 12 days, 0.85 liters of distilled water filtered after soaking oak chips is sprayed over the spirit, and the mixture is left to stand for 2.3 days. 240 grams of the same type of toasted oak chips are suspended for every 50 liters of spirit. After four and a half years of aging, the spirit is blended according to the specified proportions.

[0052] Example 3

[0053] (I) Preparation of pear pulp

[0054] Select late-autumn yellow pears of uniform ripeness, wash, core, and cut into chunks, then freeze at -10℃ for 24 hours. After juicing, add 3g of gelatin and 2g of tannin to every 100L of pear juice, clarify using the gelatin-tannin method, stir well, and let stand for 8 hours to obtain clarified pear juice.

[0055] (II) First Preparation

[0056] For every 100 catties of pear pulp, mix 18 catties of purified water and 5 catties of white sugar thoroughly, then add fruit koji and ferment in a vat. After 2 hours, add 0.4% Rhizopus koji and adjust the pH to 4.5; after 1.8 hours, add 0.4% koji and seal the container. For the first 7 days of fermentation, the micro-aerobic rate is 1.0 L / hour; for the next 10 days, micro-aerobic supply is stopped; for the last 5 days, the micro-aerobic rate is 0.5 L / hour. When the sugar content of the fermentation liquid drops to 8°Bx, add fresh pear juice at a rate of 3% of the fermentation liquid volume per hour, while adding white sugar in batches every 24 hours at a ratio of 1 g per liter of fermentation liquid. After 96 hours, add 6% white sugar, heat to 35°C and maintain for 2 hours, seal the vat after 25 minutes, and distill after 45 days.

[0057] During distillation, the pressure was controlled at 0.08 MPa, the temperature at 70℃, and the reflux ratio at 8. 40%-60% vol fraction was collected, and the distillate was also fractionated at atmospheric pressure. 5% of the distillate was used for blending, and the lees were collected for subsequent preparations.

[0058] (III) Second preparation

[0059] Add the first batch of prepared lees, pear pulp, white sugar, and fruit koji in a ratio of 30:70:5:0.3. After 1.8 hours, add 0.4% Rhizopus koji, after another 1.8 hours, add 0.4% aromatic koji, and after 96 hours, add 6% white sugar. Seal the container after 25 minutes and distill after 45 days. Take 10% of the alcohol to blend, and keep the lees.

[0060] (iv) Third preparation

[0061] Mix pear pulp, second-prepared lees, white sugar, and fruit koji in a ratio of 50:50:5:0.3, put it into a vat and cover it from light. Add 0.2% Rhizopus koji within 1 hour, add 0.2% aromatic koji after 1 hour, add 6% white sugar after 72 hours, seal the vat after 25 minutes, and distill and blend the liquor after 45 days.

[0062] (v) Fourth preparation

[0063] The spirit is placed in double-barreled oak barrels. The inner barrel is 120cm high and 60cm in diameter, while the outer barrel's long axis is 20cm larger than the inner barrel's diameter, and its short axis is 12cm larger. The insulation layer is 8cm thick. Distilled water is sprayed on the barrel every 14 days (1 liter per square meter), and the mixture is allowed to stand for 3 days. 300 grams of oak chips are suspended for every 50 liters of spirit. The mixture is then aged for five years and blended according to specific proportions to produce the final spirit.

[0064] A comparative sample was added, using late-autumn yellow pears, which were washed and juiced directly. Five kilograms of white sugar were added per 100 kilograms of pear juice, along with fruit koji, and the mixture was fermented in vats. No staged micro-aeration or supplementary feeding was performed during fermentation. After fermentation, the mixture was directly distilled at atmospheric pressure, collecting the fraction with an alcohol content of 30%-50% vol as the base spirit for the finished product, without repeated processing and recycling of the lees. The spirit was then stored in ordinary oak barrels for three years before blending into the final product.

[0065] According to relevant testing methods, the relevant physicochemical indicators of Examples 1-3 and comparative examples were tested, and the results are shown in the table below:

[0066] Table 1: Relevant Physicochemical Indicators of Examples 1-3 and Comparative Examples

[0067] The nutrient content of Examples 1-3 and the comparative examples was tested according to relevant testing methods, and the results are shown in the table below:

[0068] Table 2: Nutritional content data of Examples 1-3 and comparative examples

[0069] The wines prepared in Examples 1-3 and the comparative examples were tasted and then sensory evaluated. Specifically, the sensory evaluation rules were as follows: an evaluation group composed of 15 brewing professionals was formed, and the sensory requirements of GB / T11856—2008 "Brandy" were used as the sensory evaluation reference standard. The samples were scored from four aspects: appearance, aroma, taste and style. The full score was 100 points, and the average score of the 15 people was taken.

[0070] The sensory evaluation criteria are shown in the table below:

[0071] Table 3: Detailed Rules for Sensory Evaluation Criteria

[0072] Sensory evaluations were conducted on Examples 1-3 and the comparative examples according to the above evaluation criteria and rules, and the results are shown in the table below:

[0073] In summary, this invention utilizes recycled distiller's grains in three stages (ratios of 30:70, 25:75, and 45:55) to gradually extract residual nutrients (such as vitamin C and various minerals). Table 2 shows the dry extract data: Examples 1-3 showed 2.0-2.3 g / L, and the comparative example showed 1.6 g / L, indicating more complete extraction of soluble substances.

[0074] Nutritional content retention: The potassium (K) content in the examples was 17.2-18.5 mg / L, while the comparative example was only 13.1 mg / L; the total polyphenol content in the examples was 8.3-9.2 mg / L, while the comparative example was only 4.1 mg / L. Multiple distillations can selectively retain trace elements and antioxidants in pear juice.

[0075] Further details can be found by referring to... Figure 5 As shown, when the number of times the preparation process is recycled is changed from 1 to 5, it is found that the wine obtained by recycling the preparation process 3 times has the highest content of nutrients (vitamin C, total sugar, potassium and total polyphenols, etc.).

[0076] Furthermore, this invention precisely controls flavor compounds through staged micro-oxygen fermentation and feeding. Specifically, micro-oxygen control is implemented in the early and middle stages: micro-oxygen (0.5-1.0L / h) is introduced 5-7 days before fermentation to promote yeast proliferation and the synthesis of flavor compounds such as esters; oxygen is stopped in the middle stage to avoid excessive oxidation; and low oxygen (0.2-0.5L / h) is used in the later stage to maintain yeast activity.

[0077] Feeding strategy: When the sugar content drops to 5-8°Bx, add fresh pear juice (1%-3% / hour) and white sugar (0.5-1g / L·time) to extend the fermentation cycle, increase alcohol content, and retain fruit aroma. Specific implementation is as follows:

[0078] In terms of sensory quality, the aroma scores of Examples 1-3 reached 28-29 points (out of 30) and the taste scores reached 32-33 points (out of 35), which were significantly higher than the 25 points (aroma) and 27 points (taste) of the comparative examples. This indicates that micro-aerobic fermentation effectively improved the harmony between pear aroma and aged aroma and reduced spiciness.

[0079] Regarding alcohol content and sugar conversion: the alcohol content of the example was 44.3-46.8% vol, while that of the comparative example was only 41.2% vol; the total sugar (reducing sugar) of the example was 1.4-1.6 g / L, while that of the comparative example was 0.8 g / L, indicating that the feeding process promoted the full conversion of sugar into alcohol, while avoiding excessive residual sugar that would affect the taste.

[0080] This invention also retains heat-sensitive nutrients by coupling vacuum distillation and rectification. Specifically, the vacuum distillation pressure is controlled at 0.05-0.08 MPa and the temperature is 60-70℃, which significantly reduces the temperature compared to traditional atmospheric distillation (usually >90℃), thereby reducing the degradation of heat-sensitive components such as vitamin C and volatile esters.

[0081] Specifically, the results are as follows: taking vitamin C content as an example, Examples 1-3 showed 10.8-12.1 mg / 100mL, close to the upper limit of typical pear juice (10 mg / 100mL), while the comparative example showed only 6.3 mg / 100mL, proving that the low-temperature process effectively preserved vitamin C.

[0082] Regarding antioxidant properties: Polyphenol content (calculated as gallic acid) data: Examples 1-3 showed 8.3-9.2 mg / L, while the comparative example showed 4.1 mg / L (lower detection). Analysis:

[0083] Polyphenols are natural antioxidants, and their content directly affects the antioxidant capacity of the wine. The total polyphenol content of the example is 2-2.2 times that of the comparative example, indicating that the present invention effectively preserves polyphenols in pear juice through low-temperature freezing to break cells (-8°C to -10°C) and gelatin-tannin clarification processes. In contrast, the comparative example, which did not employ freezing and precise clarification, suffered significant polyphenol loss.

[0084] Furthermore, the present invention also improves flavor purity by controlling the distillation reflux ratio. Specifically, the distillation reflux ratio is controlled at 5-8. By using a high reflux ratio, low-boiling-point irritating substances (such as aldehydes) are separated, while high-boiling-point esters (such as ethyl acetate) and terpenes are retained.

[0085] Specifically, the total ester content in Examples 1-3 was 0.62-0.72 g / L, while the comparative example was only 0.35 g / L (close to the lower limit of the standard), indicating that the distillation process significantly increased the concentration of flavor substances.

[0086] Methanol control: The methanol content in the example was 1.1-1.3 g / L, and in the comparative example it was 1.8 g / L, indicating that vacuum distillation combined with rectification can effectively reduce harmful substances such as fusel oils and improve safety.

[0087] It is worth mentioning that, referring to Figure 2This invention, by adjusting the alcohol content of the initial and secondary fractions collected during distillation, significantly alters the taste, aroma, and other parameters of the resulting spirit. The sensory score is also affected by varying the collected alcohol content, as shown in Figure 2. From the peak region of the surface in the figure, it can be inferred that the sensory score reaches its highest when the initial and secondary fraction alcohol contents are in a specific combination. Assuming the peak is reached when the initial fraction alcohol content is approximately 40% vol and the secondary fraction alcohol content is approximately 20% vol, this indicates that under this combination, the product retains sufficient aroma components while effectively removing undesirable flavor substances, achieving an optimal balance between aroma and taste.

[0088] In addition, refer to Figure 3 This invention, by improving relevant process parameters, can produce wine with a concentration of 40%-60% vol. Testing revealed that the content of various nutrients did not change significantly at different alcohol concentrations within this range. For example, while the vitamin C content showed an upward trend as the alcohol concentration gradually increased from 40% vol to 50% vol, the increase was relatively gradual. At 50% vol, the vitamin C content was approximately 8.10 mg / 100 mL, and at 60% vol, it was approximately 8.04 mg / 100 mL, with a maximum variation of only about 0.06 mg / 100 mL throughout the entire range. This indicates that within the 40%-60% vol alcohol concentration range, despite variations in alcohol concentration, the vitamin C content did not fluctuate drastically; the contents of total sugar, potassium, and total polyphenols remained relatively stable. Figure 3 The changes shown are not significant.

[0089] And reference Figure 4 This invention, during the fermentation process, allows for adjustments to the oxygenation levels during the first 5-7 days and the last 3-5 days, thereby altering the final appearance, taste, and style scores of the resulting wine. Specific results are shown in Figure 4. When the oxygenation level remains relatively stable during the last 3-5 days, increasing the oxygenation level during the first 5-7 days gradually raises the sensory score. This is because, in the early stages of fermentation, appropriately increasing the oxygenation level promotes aerobic respiration of the yeast, accelerates yeast proliferation, and provides a sufficient number of yeast cells for subsequent alcoholic fermentation. This facilitates smooth fermentation, resulting in better aroma, taste, and overall sensory performance, thus improving the wine's sensory score. For example, when the value of A is low, yeast proliferation may be insufficient, leading to incomplete fermentation and poor aroma and taste, resulting in a lower sensory score. Conversely, as A increases, yeast metabolism becomes more efficient, improving the wine's quality.

[0090] When the initial oxygenation level is fixed for 5-7 days, increasing the oxygenation level in the last 3-5 days also improves the sensory score. In the later stages of fermentation, appropriate oxygenation can promote the oxidation and synthesis of some flavor compounds, improving the aroma and taste of the wine. For example, adequate oxygen can promote the formation of aroma compounds such as esters, making the wine more aromatic and full-bodied, thus improving the sensory score. At the top of the fermentation curve, the oxygenation level is 1.0 L / h for 5-7 days and 0.47 L / h for the last 3-5 days. At this point, the wine may have a clear and bright appearance, a mellow and harmonious taste, and a unique and distinctive style, achieving the highest sensory score. This demonstrates the technical effect of this invention in effectively improving wine quality by adjusting the oxygenation level.

[0091] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A brewing process for high-proof brandy made from late autumn yellow pears, characterized in that, The process includes the following steps: S1. First Preparation: Add raw materials according to the ratio of 15-20 catties of purified water and 5 catties of white sugar per 100 catties of pear pulp. After stirring evenly, add fruit koji and ferment in a vat. During fermentation, use a stirring device to stir the mixture. After 1-3 hours, add 0.2-0.4% Rhizopus koji and adjust the pH to 4.0-4.

5. After 40 minutes to 2 hours, add 0.3-0.4% aromatic koji and seal the container. After 72-96 hours, add 5-6% white sugar and heat to 30-35℃ and maintain for 1-2 hours. After 20-25 minutes, seal the vat. After 45 days, distill and take 5% of the alcohol for blending. Collect the lees for the second preparation. S2. Second preparation: Add the lees, pear pulp, white sugar, and fruit koji from the first preparation in a ratio of 30:70:5:0.

3. After pretreatment of the lees, put them into a vat. After 1-3 hours, add 0.2-0.4% Rhizopus koji. After 40 minutes to 2 hours, add 0.3-0.4% aromatic koji. In the fourth step, after 72-96 hours, add 5-6% white sugar. After 20-25 minutes, seal the vat. After 45 days, put it into a distillation pot. Take out 10% of the liquor for later blending. Take out the lees from the distillation pot for the third preparation process. S3. Third preparation: Pear pulp, second preparation lees, white sugar, and fruit koji are added in a ratio of 50:50:5:0.2-0.

3. After being placed in a vat, the mixture is protected from light. After 1 hour, 0.2% Rhizopus koji is added. After another 1 hour, 0.2% aromatic koji is added. After 72 hours, white sugar is added at 5-6%. The vat is sealed after 20-25 minutes. After 45 days, the mixture is transferred to a distillation pot, and 100% of the alcohol is taken out for later blending. S4. Fourth preparation: Store for three to five years, then blend the finished wine according to the specified proportions.

2. The brewing process for high-proof brandy made from late autumn yellow pears according to claim 1, characterized in that, The method for preparing pear juice is as follows: Select high-quality late autumn yellow pears, wash, remove the cores, cut into pieces, and freeze at -5℃ to -10℃ for 12-24 hours. After juicing, clarify the pear juice using the gelatin-tannin method. During the clarification process, add 2-3g of gelatin and 1-2g of tannin per 100L of pear juice. First, dissolve the gelatin in warm water, and then dissolve the tannin in a small amount of alcohol before adding it to the pear juice. Stir well and let it stand for 6-8 hours.

3. The brewing process for high-proof brandy made from late autumn yellow pears according to claim 1, characterized in that, During the fermentation process of each preparation process, the micro-oxygen supply is 0.5-1.0 liters / hour for the first 5-7 days, stops for the middle 7-10 days, and is 0.2-0.5 liters / hour for the last 3-5 days. When the sugar content in the fermentation broth drops to 5-8°Bx, pretreated fresh pear juice is continuously added, with the addition rate controlled at 1%-3% of the fermentation broth volume per hour. At the same time, every 12-24 hours, 0.5-1g of white sugar is added in batches according to the ratio of 0.5-1g of white sugar per liter of fermentation broth.

4. The brewing process for high-proof brandy made from late autumn yellow pears according to claim 1, characterized in that, During the distillation process of each preparation process, the pressure of vacuum distillation is controlled at 0.05-0.08 MPa, the temperature is 60-70℃, the rectification reflux ratio is controlled at 5-8, and the distillate with an alcohol content of 40%-60% vol is collected. At the same time, a combination of atmospheric distillation and fractional distillation is adopted. First, atmospheric distillation is carried out to collect the initial fraction with an alcohol content of 30%-50% vol. When the alcohol content drops below 30% vol, the distillation temperature and condensation conditions are adjusted to collect the secondary fraction with an alcohol content of 10%-30% vol. The initial fraction and the secondary fraction are mixed and blended according to different proportions.

5. The brewing process for high-proof brandy made from late autumn yellow pears according to claim 1, characterized in that, In the fourth preparation process, the wine is placed in oak barrels and sprayed with distilled water that has been soaked and filtered through oak chips every 1-2 weeks, at a rate of 0.5-1 liter per square meter, and left to stand for 2-3 days.

6. The brewing process for high-proof brandy made from late autumn yellow pears according to claim 5, characterized in that, The oak barrels used to hold the wine have a double-barrel structure consisting of an inner barrel and an outer barrel. The inner barrel is a conventional cylindrical shape used to hold the wine, while the outer barrel is elliptical with its major axis coinciding with the central axis of the inner barrel's cylinder. A gap is left between the inner and outer barrels to form an air insulation layer. The height of the inner barrel can be 60-120cm and its diameter can be 30-60cm. The major axis of the outer barrel's ellipse is 10-20cm longer than the diameter of the inner barrel, and the minor axis is 6-12cm longer than the diameter of the inner barrel. The thickness of the air insulation layer between the inner and outer barrels is 3-8cm.

7. The brewing process for high-proof brandy made from late autumn yellow pears according to claim 5, characterized in that, Hang an appropriate amount of oak chips in the inner barrel containing the wine. The oak chips are thin slices made of the same material as the oak barrel and have been toasted. Hang 200-300 grams of oak chips for every 50 liters of wine.

8. A high-proof brandy produced using the high-proof brandy brewing process of late autumn yellow pears as described in any one of claims 1-7.

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