CN106967552A - A kind of brew method of purple potato Huangguan Pear compound fruit wine - Google Patents

Abstract

A brewing method of purple sweet potato huangguan pear compound fruit wine, including material selection and raw material pretreatment, enzymatic hydrolysis and saccharification, SO2 sterilization, sugar and _acid adjustment, preparation of yeast seed liquid, inoculation and fermentation, aging fermentation, bottle change and clarification , finished product deployment and diatomaceous earth filtration. In the present invention, the mashed purple sweet potato is first enzymolyzed by amylase and then mixed with pear juice, and then saccharified by pectinase and glucoamylase. It has reached more than 68%, and the saccharification juice yield of purple potato Huangguan pear juice has reached more than 70%; the purple potato Huangguan brewed is made by using the fermentation method of Pichia wisteria and the appropriate fermentation process conditions. The alcohol content of the pear compound fruit wine has reached more than 12% vol. The purple sweet potato and yellow crown pear compound fruit wine prepared by the invention has clear and transparent color, delicate and stable texture, has both the fragrant and fruity aroma and nutritional and health care effects of purple sweet potato and yellow crown pear, has unique flavor, is mellow and refreshing, and is rich in nutrition.

Description

A kind of brewing method of purple sweet potato yellow crown pear compound fruit wine

technical field

The invention relates to the technical field of fruit wine production, in particular to a brewing method of purple sweet potato, yellow crown and pear compound fruit wine.

Background technique

Fruit wine is a low-alcohol beverage wine brewed from plant fruits through fermentation. Compared with white wine, it has the characteristics of low alcohol content, high nutrition, and brain fitness.

Purple potato is also called black potato, and its flesh is purple to deep purple. In addition to the starch, dietary fiber, vitamins and other nutrients contained in ordinary sweet potatoes, it is rich in minerals, rich in anthocyanins, and has high medicinal properties. It is an ideal crop that is easy to cultivate and can be used for both medicine and food. According to test results, purple sweet potato is rich in zinc, calcium, magnesium and other beneficial elements for human body, especially rich in selenium, which has been called the king of anti-cancer by the world medical circle. The anthocyanins it is rich in have been proven to have health effects such as improving human immunity, anti-cancer and anti-cancer, softening blood vessels, lowering blood pressure, and lowering blood lipids.

Huangguan pear is a hybrid of snow pear and Japanese new century pear. After ripening, the fruit has yellow skin, smooth and rust-free surface, small and dense fruit spots, white flesh, fine and crunchy flesh, and rich juice content. The flavor is sour and sweet, and it is one of the main varieties of pears in my country. The nutrients in pears can keep body cells in a healthy state, assist organs to detoxify, purify the body, soften blood vessels, improve blood circulation, and transport calcium to bones to strengthen bone calcium. In addition, the heated pear juice contains a lot of polyphenols, which has good anti-cancer properties.

The patent with the publication number CN105950341A discloses a preparation method of purple sweet potato pear wine with nutritional and health care functions. The preparation method includes the following steps: (1) beating the purple sweet potato, liquefying, saccharifying, and taking its clear juice to obtain the purple sweet potato juice; squeeze pears to obtain pear juice; (2) put purple potato juice and pear juice into a sterile fermenter after mixing, and add activated yeast to ferment, then clarify and filter, and then fill and sterilize. The finished purple potato pear wine was obtained. In this invention, only the purple sweet potato is liquefied and saccharified to obtain purple sweet potato juice, and then the purple sweet potato juice is mixed with pear juice and then aseptically fermented. The obtained purple potato pear compound fruit wine has low alcohol content and opaque color.

Contents of the invention

The object of the present invention is to provide a kind of brewing method of purple sweet potato Huangguan pear compound fruit wine, this method can improve the enzymatic hydrolysis juice yield of purple sweet potato, the saccharification juice yield of purple potato Huangguan pear juice, the alcohol degree of fruit wine and the alcohol content of fruit wine. Color transparency.

In order to achieve the above object, the invention provides a kind of brewing method of purple sweet potato huangguan pear compound fruit wine, carry out according to the following steps:

(1) Material selection and raw material pretreatment: select high-quality fresh purple sweet potatoes, wash and cut into pieces, then carry out color protection treatment and blanching treatment successively, remove and cool, then beat to obtain purple sweet potato puree, and set aside; wash fresh Huangguan pears Peel and remove the core, then cut into pieces and press to obtain pear juice, set aside;

(2) Enzymatic hydrolysis and saccharification: Weigh the raw materials respectively according to the weight ratio between the purple potato puree and pear juice is 1:2～2:1, put the purple potato puree in a beaker, add distilled water to rinse it into the conical flask Prepare the enzymatic hydrolysis solution, add 0.1-0.3% of the mass of purple potato mash amylase into the conical flask, place the conical flask in a water bath at 45-55°C, control the enzymatic hydrolysis pH to 5.5-6.5, and enzymatic hydrolysis The time is 25～35min; After adding 0.1～0.3% pectinase of purple potato puree and pear juice total mass and 0.1～0.3% glucoamylase of purple potato puree and pear juice total mass in the Erlenmeyer flask successively, the conical The shaped bottle is placed in a water bath at 45-55°C, the saccharification pH is controlled at 3.5-5.5, and the saccharification time is 85-95 minutes; after the saccharification is completed, suction filtration is performed, and the supernatant liquid is obtained to obtain the saccharification liquid of purple potato Huangguan pear juice , and pump the saccharification liquid of purple sweet potato and yellow crown pear juice into the fermenter, and the loading is 70-80% of the capacity of the fermenter;

( ₃ ) SO2 Sterilization: add the sulfurous acid of concentration 5～8% in fermenter by the weight ratio of 1/1000～1/900 between the saccharified liquid of purple sweet potato Huangguan pear juice and sulfurous acid;

(4) Adjusting sugar and acidity: measure the sugar content and acid content of the saccharified liquid of purple sweet potato, Huangguan and pear juice. %; when the acid content is insufficient, by adding citric acid, the final acid content of the saccharification liquid of purple sweet potato and pear juice reaches 8-12g/L;

(5) Preparation of yeast seed liquid: Screening of Kudriaz Pichia wischler with high ethanol tolerance, high sugar tolerance, high osmotic tolerance, acid _- base tolerance and high SO2 tolerance Yeast is expanded and cultivated to obtain yeast seed liquid;

(6) Centrifuge the yeast seed liquid to obtain solid matter, centrifugation conditions: rotation speed 4000r/min, centrifugation temperature 4°C, centrifugation time 1min, and then resuspend the solid matter through 9% normal saline for multiple elution ;

(7) inoculation fermentation: press 3～6% (v/v) of purple sweet potato huangguan pear juice amount in the fermentation tank, inoculate the yeast seed liquid after step (6) processing to after step (4) processing The main fermentation is carried out in the saccharification liquid of purple sweet potato Huangguan pear juice. The main fermentation adopts closed fermentation. The fermentation time is 11 to 14 days. The fermentation temperature is controlled at 28°C, and the temperature is controlled not to exceed 25°C during the peak fermentation period;

(8) Aging fermentation: After the main fermentation, the bottle is changed for the first time, and post-fermentation is carried out for 7 to 10 days after the bottle is changed;

(9) Re-bottle clarification: change the bottle once every 4-6 days after post-fermentation, and then change the bottle 2-3 times after every 10-15 days; , if the transparency of the compound fruit wine is still not enough, clarify by adding gelatin and tannin; after the clarification is completed, filter to obtain the first wine, seal the first wine and age it below 10°C for at least 6 months;

(10) Blending of finished products: After the aging is completed, the alcohol content, acidity, sugar content, microbial content and stability of the initial wine are tested; according to the NY/T 1508-2007 green fruit wine standard, the alcohol content (20°C) is 7-18 %, acid (calculated as tartaric acid) is 4.0-9.0g/L, and the standard of semi-dry total sugar is 4.1-12.0g/L to deploy the finished product; when the alcohol content is not up to the standard, the alcohol content is adjusted by adding alcohol, When the acidity is insufficient, the acidity is adjusted by adding citric acid, and when the sugar content is insufficient, the sugar content is adjusted by adding the concentrated juice of Huangguan pear;

(11) Diatomite filtration: the prepared purple sweet potato, Huangguan pear compound fruit wine is filtered with diatomaceous earth, pasteurized after bottled, and finally the purple sweet potato, Huangguan pear compound fruit wine is filled in aseptic glass bottles.

Preferably, the color protection treatment in the step (1) is soaking the purple potato pieces in 1% disodium stannous citrate solution for 4-6 minutes.

Preferably, the blanching treatment in the step (1) is to cut the purple potato pieces that have undergone the color protection treatment into slices and put them into hot water at 95-100° C. for 9-10 minutes.

Preferably, the process conditions for the enzymatic hydrolysis of purple sweet potato in the step (2) are as follows: after adding 0.1% amylase of purple sweet potato puree mass to the conical flask, place the conical flask in a water bath at 50°C, and the enzymatic The hydrolysis pH was controlled at 6.0, and the enzymatic hydrolysis time was 30 minutes.

Preferably, the process conditions for saccharification of purple sweet potato and pear juice mixed fruit juice in the step (2) are: 0.10% pectinase of the total mass of purple potato puree and pear juice and 0.10% of the total mass of purple potato puree and pear juice After the saccharification enzyme, the Erlenmeyer flask was placed in a water bath at 50°C, the saccharification pH was controlled at 4.0, and the saccharification time was 90 minutes.

Preferably, in the step (3), the weight ratio between the saccharified liquid of purple sweet potato huangguan pear juice and sulfurous acid is 1/950, and the concentration of sulfurous acid is 6%.

Compared with the prior art, the present invention first uses amylase to enzymolyze the purple potato mash, then mixes it with pear juice, and then uses pectinase and glucoamylase to saccharify the purple potato and Huangguan pear juice together. Under the condition of hydrolysis and saccharification process, the enzymatic hydrolysis juice yield of purple potato puree reached more than 68%, and the saccharification juice yield of purple potato Huangguan pear juice reached more than 70%; And with proper fermentation process conditions, the alcohol content of the brewed purple sweet potato and yellow crown pear compound fruit wine has reached more than 12% vol. The purple sweet potato and yellow crown pear compound fruit wine prepared by the present invention is clear and transparent in color, delicate and stable in texture, has both the fragrance and fruity aroma and nutritional and health care effects of purple sweet potato and yellow crown pear, and has a full body, unique flavor, round and refreshing taste, and It is mellow and nutritious, and the brewing cost is economical, which can realize large-scale production.

detailed description

The present invention is described in further detail below in conjunction with embodiment.

Embodiment one

A kind of brewing method of purple sweet potato yellow crown pear compound fruit wine is carried out according to the following steps:

(1) Material selection and raw material pretreatment: select high-quality fresh purple sweet potatoes, wash and cut into pieces, soak in 1% stannous disodium citrate solution for 4 minutes for color protection treatment, and put the purple sweet potatoes after color protection treatment Cut the pieces into slices, put them in hot water at 95°C for 10 minutes, remove them and cool them down, and beat them to obtain purple sweet potato mash, which will be used for later use; wash the fresh Huangguan pears, peel and remove the core, cut them into pieces, and press them to obtain mashed potatoes. pear juice, set aside;

(2) Enzymatic hydrolysis and saccharification: Weigh the raw materials according to the weight ratio of purple sweet potato puree and pear juice as 1:2, put the purple sweet potato puree in a beaker, add distilled water to rinse and wash it into a conical flask to prepare an enzymatic hydrolysis solution , after adding 0.3% amylase of purple potato puree mass to the Erlenmeyer flask, place the Erlenmeyer flask in a water bath at 45°C, control the enzymolysis pH to 5.5, and the enzymolysis time is 35min; After adding 0.3% pectinase and 0.3% glucoamylase in the total mass of purple potato puree and pear juice, the Erlenmeyer flask was placed in a water bath at 45°C, and the saccharification pH was controlled at 3.5 , the saccharification time is 95min; after the saccharification is completed, suction filtration is carried out, and the supernatant liquid is taken to obtain the saccharified liquid of purple sweet potato and yellow crown pear juice, and the saccharified liquid of purple potato and yellow crown pear juice is pumped into the fermenter, and the capacity of the fermenter is 70-80% of capacity;

( ₃ ) SO Sterilization: add the sulfurous acid of concentration 8% in the fermenter by the weight ratio of 1/1000 between the saccharified liquid of purple sweet potato Huangguan pear juice and sulfurous acid;

(4) Adjusting sugar and acidity: measure the sugar content and acid content of the saccharified liquid of purple sweet potato, Huangguan and pear juice. %; when the acid content is insufficient, by adding citric acid, the final acid content of the saccharification liquid of purple sweet potato and pear juice reaches 8-12g/L;

(5) Preparation of yeast seed liquid: Screening of Kudriaz Pichia wischler with high ethanol tolerance, high sugar tolerance, high osmotic tolerance, acid _- base tolerance and high SO2 tolerance Yeast is expanded and cultivated to obtain yeast seed liquid;

(6) Centrifuge the yeast seed liquid to obtain solid matter, centrifugation conditions: rotation speed 4000r/min, centrifugation temperature 4°C, centrifugation time 1min, and then resuspend the solid matter through 9% normal saline for multiple elution ;

(7) inoculation fermentation: press 3～6% (v/v) of purple sweet potato huangguan pear juice amount in the fermentation tank, inoculate the yeast seed liquid after step (6) processing to after step (4) processing The main fermentation is carried out in the saccharification liquid of purple sweet potato Huangguan pear juice. The main fermentation adopts closed fermentation. The fermentation time is 14 days. The fermentation temperature is controlled at 28 ° C, and the temperature is controlled not to exceed 25 ° C during the peak fermentation period;

(8) Aging fermentation: After the main fermentation, the bottle is changed for the first time, and after the bottle is changed, post-fermentation is carried out for 10 days;

(9) Re-bottle clarification: change the bottle once every 4-6 days after post-fermentation, and then change the bottle 2-3 times after every 10-15 days; , if the transparency of the compound fruit wine is still not enough, clarify by adding gelatin and tannin; after the clarification is completed, filter to obtain the first wine, seal the first wine and age it below 10°C for at least 6 months;

(10) Blending of finished products: After the aging is completed, the alcohol content of the initial wine is 12%, the acid (calculated as tartaric acid) is 5.4g/L, and the sugar content is 4.8g/L. The microbial content and stability are in line with NY/T 1508- 2007 Green Fruit Wine Standard;

(11) Diatomite filtration: the prepared purple sweet potato, Huangguan pear compound fruit wine is filtered with diatomaceous earth, pasteurized after bottled, and finally the purple sweet potato, Huangguan pear compound fruit wine is filled in aseptic glass bottles.

The compound fruit wine is clear and transparent in color, delicate and stable in texture, and has the aroma and fruity aroma of purple sweet potato and yellow crown pear. Provisions of the Green Fruit Wine Standard. After testing, in this embodiment, the enzymatic hydrolysis yield of purple potato puree reaches 72.5%, and the saccharification yield of purple sweet potato Huangguan pear juice reaches 75.8%.

Embodiment two

A kind of brewing method of purple sweet potato yellow crown pear compound fruit wine is carried out according to the following steps:

(1) Material selection and raw material pretreatment: select high-quality fresh purple sweet potatoes, wash and cut into pieces, soak them in 1% disodium stannous citrate solution for 5 minutes for color protection treatment, and put the purple sweet potatoes after color protection treatment Cut the pieces into slices and put them in hot water at 98°C for 9.5 minutes, remove and cool, and beat to obtain purple sweet potato mash for later use; wash the fresh Huangguan pears, peel and remove the core, then cut into pieces and press Get pear juice and set aside;

(2) Enzymatic hydrolysis and saccharification: Weigh the raw materials according to the weight ratio between the purple potato puree and pear juice as 3:2, put the purple potato puree in a beaker, add distilled water to rinse it into a conical flask to prepare an enzymatic hydrolysis solution , after adding 0.1% amylase from purple potato puree to the Erlenmeyer flask, place the Erlenmeyer flask in a water bath at 50°C, control the enzymolysis pH to 6.0, and enzymolysis time is 30min; After adding 0.1% pectinase and 0.1% glucoamylase in the total mass of purple potato puree and pear juice, the Erlenmeyer flask was placed in a water bath at 50°C, and the saccharification pH was controlled at 4.0 , the saccharification time is 90 minutes; after the saccharification is completed, suction filtration is carried out, and the supernatant liquid is taken to obtain the saccharified liquid of purple potato, Huangguan and pear juice, and the saccharified liquid of purple potato, Huangguan and pear juice is pumped into the fermenter, and the capacity of the fermenter is 70-80% of capacity;

( ₃ ) SO Sterilization: add the sulfurous acid of concentration 6% in fermenter by the weight ratio of 1/950 between purple sweet potato Huangguan pear juice saccharification liquid and sulfurous acid;

(4) Adjusting sugar and acidity: measure the sugar content and acid content of the saccharified liquid of purple sweet potato, Huangguan and pear juice. %; when the acid content is insufficient, by adding citric acid, the final acid content of the saccharification liquid of purple sweet potato and pear juice reaches 8-12g/L;

(5) Preparation of yeast seed liquid: Screening of Kudriaz Pichia wischler with high ethanol tolerance, high sugar tolerance, high osmotic tolerance, acid _- base tolerance and high SO2 tolerance Yeast is expanded and cultivated to obtain yeast seed liquid;

(6) Centrifuge the yeast seed liquid to obtain solid matter, centrifugation conditions: rotation speed 4000r/min, centrifugation temperature 4°C, centrifugation time 1min, and then resuspend the solid matter through 9% normal saline for multiple elution ;

(7) inoculation fermentation: press 3～6% (v/v) of purple sweet potato huangguan pear juice amount in the fermentation tank, inoculate the yeast seed liquid after step (6) processing to after step (4) processing The main fermentation is carried out in the saccharification liquid of purple sweet potato Huangguan pear juice. The main fermentation adopts closed fermentation. The fermentation time is 11 days. The fermentation temperature is controlled at 28 ° C, and the temperature is controlled not to exceed 25 ° C during the peak fermentation period;

(8) Aging fermentation: After the main fermentation, the bottle is changed for the first time, and after the bottle is changed, post-fermentation is carried out for 7 days;

(9) Re-bottle clarification: change the bottle once every 4-6 days after post-fermentation, and then change the bottle 2-3 times after every 10-15 days; , if the transparency of the compound fruit wine is still not enough, clarify by adding gelatin and tannin; after the clarification is completed, filter to obtain the first wine, seal the first wine and age it below 10°C for at least 6 months;

(10) Blending of finished products: After the aging is completed, the alcohol content of the initial wine is 14%, the acid (calculated as tartaric acid) is 6.8g/L, and the sugar content is 7.5g/L. The microbial content and stability are in line with NY/T 1508- 2007 Green Fruit Wine Standard;

(11) Diatomite filtration: the prepared purple sweet potato, Huangguan pear compound fruit wine is filtered with diatomaceous earth, pasteurized after bottled, and finally the purple sweet potato, Huangguan pear compound fruit wine is filled in aseptic glass bottles.

The compound fruit wine is clear and transparent in color, delicate and stable in texture, and has the aroma and fruity aroma of purple sweet potato and yellow crown pear. Provisions of the Green Fruit Wine Standard. After testing, in this embodiment, the enzymatic hydrolysis yield of purple potato puree reaches 75.5%, and the saccharification yield of purple potato Huangguan pear juice reaches 73.6%.

Embodiment three

A kind of brewing method of purple sweet potato yellow crown pear compound fruit wine is carried out according to the following steps:

(1) Material selection and raw material pretreatment: select high-quality fresh purple sweet potatoes, wash and cut into pieces, soak in 1% stannous disodium citrate solution for 6 minutes for color protection treatment, and put the purple sweet potatoes after color protection treatment Cut the pieces into slices, put them into hot water at 100°C for 9 minutes, take them out and cool them down, and beat them to obtain purple potato mash, which will be used for later use; wash the fresh Huangguan pears, peel and remove the core, then cut into pieces and press to obtain pear juice, set aside;

(2) Enzymatic hydrolysis and saccharification: Weigh the raw materials respectively according to the weight ratio between the purple sweet potato puree and pear juice as 2:1, put the purple sweet potato puree in a beaker, add distilled water to rinse and wash it into a conical flask to prepare an enzymatic hydrolysis solution , after adding 0.2% amylase of purple potato puree mass to the Erlenmeyer flask, place the Erlenmeyer flask in a water bath at 55°C, control the enzymolysis pH to 6.5, and enzymolysis time is 25min; After adding 0.2% pectinase and 0.2% glucoamylase in the total mass of purple potato puree and pear juice, the Erlenmeyer flask was placed in a water bath at 55°C, and the saccharification pH was controlled at 5.5 , the saccharification time is 85min; after the saccharification is completed, suction filtration is carried out, and the supernatant liquid is taken to obtain the saccharified liquid of purple sweet potato and yellow crown pear juice, and the saccharified liquid of purple potato and yellow crown pear juice is pumped into the fermenter, and the capacity of the fermenter is 70-80% of capacity;

( ₃ ) SO Sterilization: add the sulfurous acid of concentration 6% in fermenter by the weight ratio of 1/900 between the saccharified liquid of purple potato Huangguan pear juice and sulfurous acid;

(4) Adjusting sugar and acidity: measure the sugar content and acid content of the saccharified liquid of purple sweet potato, Huangguan and pear juice. %; when the acid content is insufficient, by adding citric acid, the final acid content of the saccharification liquid of purple sweet potato and pear juice reaches 8-12g/L;

(5) Preparation of yeast seed liquid: Screening of Kudriaz Pichia wischler with high ethanol tolerance, high sugar tolerance, high osmotic tolerance, acid _- base tolerance and high SO2 tolerance Yeast is expanded and cultivated to obtain yeast seed liquid;

(6) Centrifuge the yeast seed liquid to obtain solid matter, centrifugation conditions: rotation speed 4000r/min, centrifugation temperature 4°C, centrifugation time 1min, and then resuspend the solid matter through 9% normal saline for multiple elution ;

(7) inoculation fermentation: press 3～6% (v/v) of purple sweet potato huangguan pear juice amount in the fermentation tank, inoculate the yeast seed liquid after step (6) processing to after step (4) processing The main fermentation is carried out in the saccharification liquid of purple sweet potato Huangguan pear juice. The main fermentation adopts closed fermentation. The fermentation time is 13 days.

(8) Aging fermentation: After the main fermentation, the bottle is changed for the first time, and after the bottle is changed, post-fermentation is carried out for 8 days;

(9) Re-bottle clarification: change the bottle once every 4-6 days after post-fermentation, and then change the bottle 2-3 times after every 10-15 days; , if the transparency of the compound fruit wine is still not enough, clarify by adding gelatin and tannin; after the clarification is completed, filter to obtain the first wine, seal the first wine and age it below 10°C for at least 6 months;

(10) Blending of finished products: After the aging is completed, the alcohol content of the initial wine is 15%, the acid (calculated as tartaric acid) is 6.4g/L, and the sugar content is 6.2g/L. The microbial content and stability are in line with NY/T 1508- 2007 Green Fruit Wine Standard;

(11) Diatomite filtration: the prepared purple sweet potato, Huangguan pear compound fruit wine is filtered with diatomaceous earth, pasteurized after bottled, and finally the purple sweet potato, Huangguan pear compound fruit wine is filled in aseptic glass bottles.

The compound fruit wine is clear and transparent in color, delicate and stable in texture, and has the aroma and fruity aroma of purple sweet potato and yellow crown pear. Provisions of the Green Fruit Wine Standard. After testing, in this embodiment, the enzymatic hydrolysis yield of purple potato puree reaches 74.2%, and the saccharification yield of purple potato Huangguan pear juice reaches 74.1%.

Claims (6)

1. a kind of brewing method of purple sweet potato yellow crown pear compound fruit wine is characterized in that, carries out according to the following steps: (1) Material selection and raw material pretreatment: select high-quality fresh purple sweet potatoes, wash and cut into pieces, then carry out color protection treatment and blanching treatment successively, remove and cool, then beat to obtain purple sweet potato puree, and set aside; wash fresh Huangguan pears Peel and remove the core, then cut into pieces and press to obtain pear juice, set aside; (2) Enzymatic hydrolysis and saccharification: Weigh the raw materials respectively according to the weight ratio between the purple potato puree and pear juice is 1:2～2:1, put the purple potato puree in a beaker, add distilled water to rinse it into the conical flask Prepare the enzymatic hydrolysis solution, add 0.1-0.3% of the mass of purple potato mash amylase into the conical flask, place the conical flask in a water bath at 45-55°C, control the enzymatic hydrolysis pH to 5.5-6.5, and enzymatic hydrolysis The time is 25～35min; After adding 0.1～0.3% pectinase of purple potato puree and pear juice total mass and 0.1～0.3% glucoamylase of purple potato puree and pear juice total mass in the Erlenmeyer flask successively, the conical The shaped bottle is placed in a water bath at 45-55°C, the saccharification pH is controlled at 3.5-5.5, and the saccharification time is 85-95 minutes; after the saccharification is completed, suction filtration is performed, and the supernatant liquid is obtained to obtain the saccharification liquid of purple potato Huangguan pear juice , and pump the saccharified liquid of purple sweet potato and yellow crown pear juice into the fermenter, and the filling capacity is 70-80% of the capacity of the fermenter; ( ₃ ) SO2 Sterilization: add the sulfurous acid of concentration 5～8% in fermenter by the weight ratio of 1/1000～1/900 between the saccharified liquid of purple sweet potato Huangguan pear juice and sulfurous acid; (4) Adjusting sugar and acidity: measure the sugar content and acid content of the saccharified liquid of purple sweet potato, Huangguan and pear juice. %; when the acid content is insufficient, by adding citric acid, the final acid content of the saccharification liquid of purple sweet potato and pear juice reaches 8-12g/L; (5) Preparation of yeast seed liquid: Screening of Kudriaz Pichia wischler with high ethanol tolerance, high sugar tolerance, high osmotic tolerance, acid _- base tolerance and high SO2 tolerance Yeast is expanded and cultivated to obtain yeast seed liquid; (6) Centrifuge the yeast seed liquid to obtain solid matter, centrifugation conditions: rotation speed 4000r/min, centrifugation temperature 4°C, centrifugation time 1min, and then resuspend the solid matter through 9% normal saline for multiple elution ; (7) inoculation fermentation: press 3～6% (v/v) of purple sweet potato huangguan pear juice amount in the fermentation tank, inoculate the yeast seed liquid after step (6) processing to after step (4) processing The main fermentation is carried out in the saccharification liquid of purple sweet potato Huangguan pear juice. The main fermentation adopts closed fermentation. The fermentation time is 11 to 14 days. The fermentation temperature is controlled at 28°C, and the temperature is controlled not to exceed 25°C during the peak fermentation period; (8) Aging fermentation: After the main fermentation, the bottle is changed for the first time, and post-fermentation is carried out for 7 to 10 days after the bottle is changed; (9) Re-bottle clarification: change the bottle once every 4-6 days after post-fermentation, and then change the bottle 2-3 times after every 10-15 days; , if the transparency of the compound fruit wine is still not enough, clarify by adding gelatin and tannin; after the clarification is completed, filter to obtain the first wine, seal the first wine and age it below 10°C for at least 6 months; (10) Blending of finished products: After the aging is completed, the alcohol content, acidity, sugar content, microbial content and stability of the initial wine are tested; according to the NY/T 1508-2007 green fruit wine standard, the alcohol content (20°C) is 7-18 %, acid (calculated as tartaric acid) is 4.0-9.0g/L, and the standard of semi-dry total sugar is 4.1-12.0g/L to deploy the finished product; when the alcohol content is not up to the standard, the alcohol content is adjusted by adding alcohol, When the acidity is insufficient, the acidity is adjusted by adding citric acid, and when the sugar content is insufficient, the sugar content is adjusted by adding the concentrated juice of Huangguan pear; (11) Diatomite filtration: the prepared purple sweet potato, Huangguan pear compound fruit wine is filtered with diatomaceous earth, pasteurized after bottled, and finally the purple sweet potato, Huangguan pear compound fruit wine is filled in aseptic glass bottles. 2. the brewing method of a kind of purple sweet potato huangguan pear compound fruit wine according to claim 1, is characterized in that, in the described step (1), the color protection treatment is that purple sweet potato pieces are put into 1% citric acid sub- Soak in tin disodium solution for 4-6 minutes. 3. the brewing method of a kind of purple sweet potato huangguan pear compound fruit wine according to claim 1 or 2, is characterized in that, the blanching treatment in the described step (1) is the purple sweet potato block after the color protection treatment Cut into flakes and blanch in hot water at 95-100°C for 9-10 minutes. 4. the brewing method of a kind of purple sweet potato yellow crown pear compound fruit wine according to claim 1 or 2 is characterized in that, the process condition of purple sweet potato enzymolysis in the described step (2) is: in conical flask After adding 0.1% amylase by the mass of purple potato puree, the Erlenmeyer flask was placed in a water bath at 50°C, the pH of the enzymolysis was controlled at 6.0, and the enzymolysis time was 30 minutes. 5. the brewing method of a kind of purple sweet potato and yellow crown pear compound fruit wine according to claim 1 and 2, is characterized in that, the processing condition of purple sweet potato and yellow crown pear mixed fruit juice saccharification in the described step (2) is: After the pectinase of 0.10% of the total mass of purple potato puree and pear juice and the saccharification enzyme of 0.10% of the total mass of purple potato puree and pear juice, the Erlenmeyer flask was placed in a water bath at 50°C, the saccharification pH was controlled at 4.0, and the saccharification The time is 90 minutes. 6. according to the brewing method of a kind of purple sweet potato Huangguan pear compound fruit wine described in claim 1 or 2, it is characterized in that, in described step (3), the weight between purple sweet potato Huangguan pear juice saccharification liquid and sulfurous acid The ratio is 1/950 and the concentration of sulfurous acid is 6%.