A brewing method for reducing the green taste of dry red wine

Abstract

The present application relates to the wine brewing technical field, specifically to a kind of brewing method for reducing green smell of dry red wine, comprising the following steps: 1) removing stem from grape, crushing into tank, adding tannin and oak chips to grape mash in tank;2) adding nitrogen source, mixed bacteria fermentation;3) circulating spray impregnation;4) post-fermentation after seed removal, post-processing.The present application adds oak chips immediately after grape crushing into tank, so that oak flavor components and fruit peel impregnation are synchronized, compared with the traditional process using oak products after fermentation, the flavor fusion of the present application is better, and the masking effect is better;Sequential mixed bacteria fermentation is carried out using del yeast and saccharomyces cerevisiae RC212, which effectively increases the types and contents of esters, alcohols, aromatic compounds and terpenes in dry red wine, and these rich fruity and floral components significantly mask the green smell in sensory, and improve the pleasantness of aroma.

Description

Technical Field

[0001] This invention relates to the field of winemaking technology, specifically to a winemaking method for reducing the raw, grassy taste of dry red wine. Background Technology

[0002] The sensory quality of wine includes its color, aroma, taste, and typography, with aroma being one of the most important sensory indicators. A rich and elegant aroma is essential for a high-quality wine. Aromas originate from the grape berries, fermentation, and aging processes, and are a concentrated expression of grape quality and winemaking techniques. A wine's aroma can provide information about its type, aging time, storage conditions, and even defects. Controlling wine aromas is crucial for producing high-quality wines.

[0003] The quality of raw materials is crucial to the quality of dry red wine production, and these materials are influenced by the terroir of the producing region. Variations in climate between years result in differences in grape quality. If, during the growing season, temperatures are low, sunlight is insufficient, rainfall is excessive, or cultivation management is poor, the grapes may ripen slowly, resulting in a pronounced green, unripe flavor at harvest. This leads to a strong green flavor in the fermented dry red wine, unpleasant aromas, and a lack of harmony. Consumers have low acceptance of this type of dry red wine and are less likely to choose it. Currently, there is no effective solution to the problem of green flavor in dry red wine. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a brewing method for reducing the green odor in dry red wine. This method, through the synergistic effect of multiple steps, can significantly reduce the content of green odor characteristic substances in dry red wine and effectively mask the green aroma sensorily, while greatly enhancing fruit and aging aromas, thereby obtaining a high-quality dry red wine with a rich and complex aroma and a mellow and harmonious taste.

[0005] To achieve the above objectives, the present invention provides a brewing method for reducing the raw, grassy taste of dry red wine, comprising the following steps:

[0006] 1) Remove the stems from the grapes, crush them and put them into a jar. Add tannins and oak chips to the grape must in the jar.

[0007] 2) Add a nitrogen source and perform mixed-culture fermentation;

[0008] 3) Circulating spray impregnation;

[0009] 4) Ferment after seed discharge, followed by post-processing.

[0010] The method of this invention is applicable to grape varieties such as Cabernet Franc, Cabernet Franc, Cabernet Sauvignon, or Merlot. The problem of raw, grassy taste in dry red wines made from grapes of these varieties when they are not fully ripe is particularly prominent, making this method more suitable.

[0011] Preferably, in step 1), the amount of tannin added is 0.15~0.2g per liter of grape must, and the amount of oak chips added is 2~3g per liter of grape must. Adding tannin immediately after crushing and filling the can promotes the oxidation of polyphenols, stabilizes pigments, and promotes the extraction of aroma substances from the grape skins; adding oak chips in advance allows oak flavor substances to be fully integrated into the grape must during the maceration stage, blending synchronously with other aroma components, laying the foundation for masking the raw, grassy taste in the later stages.

[0012] Preferably, in step 2), the nitrogen source is an amino acid or ammonium salt, and the amount of nitrogen added is 200-250 mg per liter of grape must. The mixed-culture fermentation process is as follows: when the grape must temperature reaches above 15°C, inoculate with *Saccharomyces cerevisiae* at a quantity of at least 1 × 10⁻⁶. 6 After 72 hours, inoculate with Saccharomyces cerevisiae RC212 and continue fermentation at 25-27°C.

[0013] Preferably, in step 3), the circulating spray impregnation operation is as follows:

[0014] 31) Spray the circulating fermentation mash 2-3 times a day, with each spray amount being 1 / 2 to 2 / 3 of the tank volume;

[0015] 32) When the specific gravity of the fermentation broth drops to 1.060~1.040, increase the open spray circulation by 1~2 times per day;

[0016] 33) When the specific gravity of the fermentation broth drops to 1.000, spray and circulate once a day, control the temperature at 20~25℃, and soak for 3~5 days;

[0017] 34) During the vigorous fermentation period, the nighttime circulation adopts a drip-type solid-liquid separation and impregnation process: the last open circulation during the day is changed to drip diversion. First, all the free-flowing juice is separated into an empty tank, so that the peel and residue are dispersed and fall to the bottom of the tank; 30%~50% of the free-flowing juice is sprayed back from the top to the original tank, so that the peel and residue are fully saturated, and the temperature is controlled at 25~27℃; the remaining 70%~50% of the clear juice is fermented at a low temperature of 20~23℃; the next morning, the clear juice is sprayed back from the top to achieve peel and residue spraying again; when the specific gravity drops to 1.040~1.030, the drip separation fermentation is stopped, and the circulation method is changed to conventional circulation impregnation.

[0018] Preferably, in step 4), the seeds are discharged when the specific gravity drops to 1.040~1.030; malic acid-lactic acid fermentation is used.

[0019] The present invention provides a brewing method for reducing the raw, grassy taste of dry red wine, which has the following advantages compared with the prior art:

[0020] 1. In this invention, oak chips are added immediately after the grapes are crushed and put into the jar, so that the oak flavor components are impregnated with the grape skins at the same time. The sweet aromas of vanilla and cream brought by the oak can mask the green taste in the grape skins as early as possible. Compared with the traditional process of using oak products after fermentation, the flavor integration of this invention is better and the masking effect is better.

[0021] 2. By supplementing the grape must with an appropriate amount of nitrogen source, sufficient nutrients are provided for the yeast, ensuring the normal reproduction and vigorous metabolism of the yeast, which is conducive to the generation of more excellent fermentation flavor substances and weakens the perception of raw green taste from a metabolic level.

[0022] 3. Sequential mixed fermentation with Dermal spore-forming yeast and Saccharomyces cerevisiae RC212 effectively increases the variety and content of aroma compounds such as esters, alcohols, aromatics and terpenes in dry red wine. These rich fruit and floral aroma components significantly mask the raw, green aromas, greatly enhancing the pleasantness of the aroma.

[0023] 4. The innovative drip-type solid-liquid separation maceration process of this invention has dual advantages: on the one hand, the process allows the fermented wine to be moderately exposed to oxygen, which helps to reduce the content of precursor substances related to raw grass flavor; on the other hand, the solid-liquid separation reduces the excessive maceration of peels and seeds, thereby reducing the amount of methoxypyrazine compounds, the main contributors to raw grass flavor, dissolved in the wine.

[0024] 5. This invention performs seed removal treatment during the middle stage of fermentation (specific gravity 1.040~1.030), which removes grape seeds in time and effectively avoids excessive leaching of immature and rough tannins from the seeds. This further eliminates the astringency and unpleasant flavor caused by inferior tannins, making the wine more rounded and harmonious. Attached Figure Description

[0025] Figure 1 This is a flavor radar chart of the dry red wine obtained by the method in Example 1.

[0026] Figure 2 This is a flavor radar chart of the dry red wine obtained by the method in Example 2.

[0027] Figure 3 This is a flavor radar chart of the dry red wine obtained by the method in Example 3.

[0028] Figure 4 This is a flavor radar chart of the dry red wine obtained by the method in Example 4.

[0029] Figure 5 This is a bar chart showing the IBMP content. Detailed Implementation

[0030] The present invention will be described below with reference to examples. These examples are only used to explain the present invention and are not intended to limit the scope of the present invention.

[0031] Example 1

[0032] A winemaking method for reducing the raw, grassy taste of dry red wine, applied in the production of Cabernet Gernischt dry red wine, includes the following process steps:

[0033] 1. Sorting and harvesting, completely destemming and gently crushing: After harvesting, the grapes are gently destemmed, crushed and put into jars;

[0034] 2. High-quality oak products and high-quality tannins are added. After the grape must is put into the jar, 2.5g / L of oak chips and 0.175g / L of tannins are added. The oak chips are from the United States, lightly roasted, and have a sweet aroma of ripe fruit, vanilla, cream, etc. The tannins are high-quality tannins from oak, chestnut or hardwood.

[0035] 3. Add a nitrogen source: add 225 mg of amino acids (ammonium salts) per liter of grape must;

[0036] 4. Mixed fermentation: When the grape must temperature reaches above 15℃, inoculate with *Saccharomyces cerevisiae* at a quantity of 1×10⁻⁶. 6 After 72 hours, the yeast was inoculated with CFU / mL and fermented at 26°C.

[0037] 5. Circulating soaking: Spray the fermented mash 2-3 times a day, each time spraying 2 / 3 of the tank volume of fermentation liquid; when the specific gravity is 1.050 during the vigorous fermentation period, increase the open spraying circulation by 1 time a day; when the specific gravity drops to 1.000, spray and circulate once a day, control the temperature at 23℃, and soak for 4 days.

[0038] Leakage-type solid-liquid separation impregnation: During the vigorous fermentation period, normal circulation is carried out during the day, with two spray cycles, each spraying 1 / 2 tank volume of fermentation liquid. At night, the circulation is changed to solid-liquid separation impregnation, that is, the last open circulation of the day is changed to leaching, first separating all the free-flowing juice into the prepared empty tank, allowing the peel and residue to fall to the bottom of the tank, and then spraying 40% of the free-flowing juice back into the original tank from the top, so that the peel and residue are fully leached, and the temperature is controlled in the range of 26℃; the remaining 70~50% of the clear juice is fermented at a low temperature in the range of 21.5℃; the next morning, the clear juice is sprayed back from the top, and the peel and residue are sprayed again. When the specific gravity drops to 1.035, leaching separation fermentation is stopped, and the circulation method is changed to conventional circulation impregnation.

[0039] 6. Seed removal process: When the specific gravity drops to 1.035, grape seeds are removed to the maximum extent possible using a special seed removal machine.

[0040] 7. Malic acid-lactic acid fermentation, clarification, storage, sterilization, and filling.

[0041] The brewing method of the control group dry red wine in Example 1 is as follows:

[0042] 1. Sorting, harvesting, destemming, crushing, and bottling;

[0043] 2. Fermentation: When the temperature of the grape must reaches above 15℃, inoculate with brewer's yeast RC212, and the fermentation temperature is 25~27℃;

[0044] 3. Circulating soaking: Spray the fermented mash 2-3 times a day, each time spraying 2 / 3 of the fermentation liquid volume; when the specific gravity of the fermentation liquid drops to 1.000, spray and circulate once a day, control the temperature at 20-25℃, and soak for 3-10 days;

[0045] 4. Malic acid-lactic acid fermentation, clarification, storage, sterilization, and filling.

[0046] According to sensory evaluation by 10 professional wine tasters, the Cabernet Sauvignon dry red wine produced using this method has a significantly weaker raw, grassy, ​​and bell pepper flavor compared to the control group. Figure 1 The sensory comprehensive score of the control group was significantly higher than that of the control group, as shown in Table 1.

[0047] Table 1. Sensory evaluation results

[0048]

[0049] Example 2

[0050] A method for reducing the grassy taste in dry red wine was applied to the production of Cabernet Franc dry red wine. After the grapes were destemmed, crushed, and placed in the tank, 2 g / L of lightly toasted American oak chips and 0.2 g / L of high-quality tannins from oak (chestnut or hardwood) were added. The nitrogen source supplement was 200 mg. Other processes were the same as in Example 1. The control group followed the same process as the control group, except that oak chips and tannins were not added; conventional processes were used. Sensory evaluation by professional wine tasters showed that the grassy taste (green, grassy, ​​green pepper) was significantly weaker than the control group. Figure 2 As shown.

[0051] Example 3

[0052] A winemaking method to reduce the green, grassy taste of dry red wine has been applied to the production of Cabernet Sauvignon dry red wine. After the grapes are destemmed, crushed, and placed in tanks, mixed fermentation is carried out, inoculated with *Delta yeast* at a quantity of 1.5 × 10⁶. 6 After 72 hours, the wine was inoculated with *Saccharomyces cerevisiae* RC212 at a concentration of cfu / mL and fermented at 25°C. The control group was inoculated with only commercial *Saccharomyces cerevisiae* RC212, and otherwise treated the same as in Example 1. Sensory evaluation by professional wine tasters showed that the raw wine had a significantly weaker grassy or green flavor (green, grassy, ​​and bell pepper-like) than the control. Figure 3 As shown.

[0053] Example 4

[0054] A method for reducing the grassy taste in dry red wine was applied to the production of Merlot dry red wine. When the specific gravity was reduced to 1.040, seeds were removed using a specialized seed-removing machine. The control group did not remove seeds; other steps were the same as in Example 1. Sensory evaluation by professional wine tasters showed that the grassy taste (green, grassy, ​​green bell pepper) was significantly weaker than the control. Figure 4 As shown.

[0055] Figure 5 A comparison of the content of 3-isobutyl-2-methoxypyrazine (IBMP), the main contributor to the green flavor in grapes, between the dry red wine obtained in Example 1 (this method) and the control group (control) shows that the content of IBMP in the Cabernet Gernischt dry red wine produced by this method is reduced by 17% compared with the control.

[0056] The types and contents of aroma compounds in the dry red wine were tested. The results showed that the Cabernet Gernischt dry red wine produced in Example 1 had 7 more esters than the control group, including methyl decanoate, ethyl 9-decenoate, ethyl 3-methylbutyrate, ethyl salicylate, ethyl phenylpropionate, ethyl myristate, and ethyl palmitate; 8 more alcohols, including cis-2-pentenol, 3-methyl-1-pentanol, 3-ethoxy-1-propanol, 2-ethylhexanol, 2-nonanol, 10-undecenol, cis-3-nonen-1-ol, and trans-5-decen-1-ol; and 1 more terpene and 1 more aromatic compound, including acetoin and β-ionone.

[0057] Table 2. Aroma substance content

[0058]

[0059] As shown in Table 2, compared with the control group, the total amount of esters in this method was 1887.52 mg / L, which increased by 124%, the total amount of alcohols increased by 19%, the total amount of aldehydes and ketones increased by 604%, the total amount of terpenes increased by 119%, the total amount of aromatics increased by 114%, and the total amount of aroma increased by 69%.

[0060] The dry red wine produced using the method in Example 1 contained high levels of 14 substances, including isobutyl acetate, isoamyl acetate, hexyl acetate, ethyl lactate, methyl octanoate, ethyl octanoate, isoamyl lactate, methyl decanoate, ethyl decanoate, diethyl succinate, phenylethyl acetate, ethyl laurate, ethyl myristate, and ethyl palmitate, which imparted a rich aroma of citrus, apple, banana, strawberry, and cherry to the wine sample, consistent with the sensory evaluation results.

[0061] The dry red wine produced using the method of Example 1 shows a significant increase in the types and contents of aroma substances such as esters, alcohols, aromatic compounds, and terpenes, which mask the "green" smell in terms of sensory perception.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for reducing the raw, grassy taste of dry red wine, characterized in that, Includes the following steps: 1) Remove the stems from the grapes, crush them and put them into a jar. Add tannins and oak chips to the grape must in the jar. 2) Add a nitrogen source and perform mixed-culture fermentation; 3) Circulating spray impregnation; 4) Ferment after seed discharge, followed by post-processing.

2. The method according to claim 1, characterized in that, The grape variety is one of Cabernet Franc, Cabernet Sauvignon, or Merlot.

3. The method according to claim 2, characterized in that, In step 1), the amount of tannin added is 0.15~0.2g per liter of grape must; the amount of oak chips added is 2~3g per liter of grape must.

4. The method according to claim 2, characterized in that, In step 2), the nitrogen source is amino acids or ammonium salts, and the amount of nitrogen added is 200-250 mg per liter of grape must.

5. The method according to claim 2, characterized in that, In step 2), the mixed-culture fermentation operation is as follows: when the grape must temperature reaches above 15°C, inoculate with *Saccharomyces cerevisiae*, at a quantity of at least 1 × 10⁻⁶. 6 After 72 hours, inoculate with Saccharomyces cerevisiae RC212 and continue fermentation at 25-27°C.

6. The method according to claim 2, characterized in that, In step 3), the circulating spray impregnation operation is as follows: 31) Spray the circulating fermentation mash 2-3 times a day, with each spray amount being 1 / 2 to 2 / 3 of the tank volume; 32) When the specific gravity of the fermentation broth drops to 1.060~1.040, increase the open spray circulation by 1~2 times per day; 33) When the specific gravity of the fermentation broth drops to 1.000, spray and circulate once a day, control the temperature at 20~25℃, and soak for 3~5 days; 34) During the vigorous fermentation period, the nighttime circulation adopts a drip-type solid-liquid separation and impregnation process: the last open circulation during the day is changed to drip diversion. First, all the free-flowing juice is separated into an empty tank, so that the peel and residue are dispersed and fall to the bottom of the tank; 30%~50% of the free-flowing juice is sprayed back from the top to the original tank, so that the peel and residue are fully saturated, and the temperature is controlled at 25~27℃; the remaining 70%~50% of the clear juice is fermented at a low temperature of 20~23℃; the next morning, the clear juice is sprayed back from the top to achieve peel and residue spraying again; when the specific gravity drops to 1.040~1.030, the drip separation fermentation is stopped, and the circulation method is changed to conventional circulation impregnation.

7. The method according to claim 2, characterized in that, In step 4), the seeds are discharged when the specific gravity drops to 1.040~1.030; malic acid-lactic acid fermentation is adopted.

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