Dual temperature dual mode fermentation process for making dry red wine and dry red wine

Abstract

This invention relates to the field of winemaking technology, specifically to a dual-temperature, dual-state fermentation method for producing dry red wine and the resulting dry red wine. The alcoholic fermentation of this method includes: inoculating a mixture of grape skins and juice with yeast, and conducting solid-liquid mixed fermentation until the yeast reaches its vigorous fermentation stage, yielding a first fermentation product; separating the first fermentation product into a solid-liquid fermentation mixture and a first fermentation broth; separately fermenting the first fermentation broth in a liquid state to obtain a second fermentation broth; mixing the second fermentation broth with the solid-liquid fermentation mixture, and continuing fermentation at the same temperature as the solid-liquid mixed fermentation to complete the alcoholic fermentation; the temperature of the solid-liquid mixed fermentation is higher than that of the liquid fermentation. This method can control the concentration and types of volatile compounds, increasing or decreasing the concentration of phenolic substances, resulting in a dry red wine with rich aromas, a full body, a deep color, and good aging potential.

Description

Technical Field

[0001] This invention relates to the field of winemaking technology, and more specifically, to a dual-temperature, dual-state fermentation method for making dry red wine and the dry red wine itself. Background Technology

[0002] Current processes or methods in winemaking typically involve controlling the extraction of phenolic substances or the increase or decrease of volatile compounds in a single way, lacking methods for simultaneously controlling multiple compounds and the differential accumulation of multiple compounds.

[0003] Existing fermentation technologies mainly include traditional fermentation, carbon dioxide impregnation, and cold impregnation. Each of these technologies has its own drawbacks, as detailed below:

[0004] (1) Traditional fermentation technology is currently the most widely used winemaking technology. After the grapes are destemmed and crushed, they are placed in a fermentation tank. After a short maceration, yeast is directly inoculated to start fermentation. During the fermentation process, capping and circulation are carried out to ensure that the fermentation liquid is in full contact with the pomace and extract polyphenols from the pomace.

[0005] Traditional fermentation processes use a fixed fermentation temperature, completing the entire fermentation process at 26-30℃, which cannot significantly enhance the aroma of the wine. Furthermore, the maceration time between the fermentation liquid and the pomace is constant, making it impossible to adjust the maceration time to meet the needs of wines from different regions and with different styles.

[0006] (2) Carbonic maceration (CMAC) is a winemaking maceration technique, belonging to the category of "whole-bunch fermentation." The characteristic of CMAC is that the whole bunch of grapes is placed directly into a fermentation tank filled with carbon dioxide. In this anaerobic environment, the grape berries undergo anaerobic metabolism and complex biochemical transformations, such as the conversion of a small amount of sugar into alcohol, the degradation of malic acid, and the generation of secondary metabolites such as phenolic acids and volatile compounds. Typically, after maceration, the grapes are pressed, and alcoholic fermentation is initiated using a clear juice fermentation method. Therefore, CMAC is suitable for producing light-bodied, bright-colored, and fruit-infused fresh dry red wines, rosé wines, and a few high-acidity white wines. The world-famous Beaujolais Nouveau is made using this technique.

[0007] Carbon dioxide maceration technology also extracts the raw, grassy taste and inferior tannins from the fruit stems, affecting the quality of the wine. The extraction of anthocyanins, tannins, and other compounds is relatively low, resulting in dry red wines produced by this process that are light in color and light in body, belonging to the fresh and smooth type of dry red wine, and are not suitable for producing high-quality dry red wines with aging potential.

[0008] (3) Cold maceration is a widely used pre-fermentation maceration technique for producing high-quality dry red wine. Its characteristics are: the raw materials are crushed and placed in tanks, then the temperature is controlled at around 5-8℃, typically maintained for 7 days or even longer. After maceration, the raw materials are warmed up, and yeast is introduced to initiate alcoholic fermentation, usually with the skins. During maceration, due to the low temperature, the raw materials hardly undergo natural fermentation, and the grape juice fully macerates the skins.

[0009] It is evident that during cold maceration, only extraction is significant, but no other biochemical reactions occur, making it impossible to effectively adjust the processing techniques according to the target wine type. Cold maceration has little impact on volatile compounds and cannot significantly enhance the aroma of the wine.

[0010] Currently, there is no fermentation method that can regulate the production and accumulation of aroma compounds, anthocyanins, and other substances in wine. Summary of the Invention

[0011] The technical problem to be solved by the present invention is to provide a dual-temperature dual-state fermentation method for brewing dry red wine and the dry red wine itself.

[0012] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0013] This invention provides a dual-temperature, dual-state fermentation method for brewing dry red wine, including alcoholic fermentation, which comprises the following steps:

[0014] S1. Inoculate the mixture of grape skins and grape juice with yeast and carry out solid-liquid mixed fermentation until the yeast enters the vigorous fermentation period to obtain the first fermentation product.

[0015] S2. The first fermentation product is divided into a solid-liquid fermentation mixture and a first fermentation broth;

[0016] S3. Perform liquid fermentation on the first fermentation broth alone to obtain the second fermentation broth;

[0017] S4. Mix the second fermentation liquid with the solid-liquid fermentation mixture, and continue fermentation at the temperature specified in the solid-liquid mixture fermentation to complete the alcohol fermentation;

[0018] The temperature of the solid-liquid mixed fermentation is higher than the temperature of the liquid fermentation.

[0019] Based on the above technical solution, the present invention can be further improved as follows.

[0020] Furthermore, the temperature of the solid-liquid mixed fermentation is 26℃~30℃.

[0021] Furthermore, the temperature of the liquid fermentation is 14℃~16℃.

[0022] Furthermore, the liquid fermentation time is 10 to 14 hours.

[0023] Furthermore, in step S4, the fermentation time at the solid-liquid mixed fermentation temperature is 20 to 30 hours.

[0024] Furthermore, in step S1, when the yeast enters the vigorous fermentation period, the specific gravity of the fermentation product is less than or equal to 1.070.

[0025] Furthermore, in step S2, the volume of the first fermentation broth accounts for 50% to 70% of the total volume of the first fermentation product.

[0026] Furthermore, in step S2, the separated solid-liquid fermentation mixture continues to undergo solid-liquid fermentation.

[0027] Further, repeat steps S2 to S4 until the specific gravity of the fermentation broth is 0.990, thus completing the alcohol fermentation.

[0028] The present invention also provides a dry red wine, which is brewed using the fermentation method described above.

[0029] The beneficial effects of this invention are as follows:

[0030] (1) The dual-temperature dual-state fermentation method for brewing dry red wine of the present invention can not only control the concentration and type of volatile compounds in dry red wine and increase the concentration of phenolic substances to achieve the requirements of enhancing the floral and fruity aroma of wine, strengthening the body, deepening the color and producing high-quality aged dry red wine; it can also reduce the concentration of phenolic substances while controlling the concentration and type of volatile compounds, so as to produce high-quality smooth dry red wine with rich floral and fruity aroma.

[0031] (2) The dual-temperature dual-state fermentation method for brewing dry red wine of the present invention can differentiate the accumulation of volatile compounds and phenolic substances according to different needs, and achieve the purpose of targeted regulation of wine flavor by adjusting different fermentation parameters, so as to realize the brewing of wines of different styles.

[0032] (3) The dual-temperature dual-state fermentation method for brewing dry red wine of the present invention can not only control the extraction of anthocyanins, tannins and other substances during the fermentation process at any time, but also produce unique aroma components and enhance yeast metabolism, thereby increasing its ester production capacity and enhancing the floral and fruity aroma of the wine.

[0033] (4) The dry red wine of the present invention has a significant and rich aroma, and at the same time, it is full-bodied, dark in color, of excellent quality, and has good aging potential. Attached Figure Description

[0034] Figure 1 The heatmap shows the changes in the concentration of each aroma substance in the wine samples of the embodiment and comparative examples of the dual-temperature dual-state fermentation method for brewing dry red wine of the present invention.

[0035] Figure 2 This is a comparison chart showing the content of volatile compounds with significant differences in the wine samples from the examples and comparative examples of the dual-temperature, dual-state fermentation method for brewing dry red wine according to the present invention. Figure 2 In this context, 'a' represents decanoic acid. Figure 2 In this context, b represents ethyl laurate. Figure 2 c represents guaiacol. Figure 2 In this context, d represents isobutanol. Figure 2 In this context, 'e' represents ethyl octanoate. Figure 2 f is caprylic acid. Figure 2 The middle g is citronellol. Figure 2 h represents pentanol. Figure 2 In this context, i represents linalool. Figure 2 J represents 3-methylthiopropanol. Figure 2 In this context, k represents 1-octen-3-ol. Figure 2 In this context, l represents ethyl 2-methylbutyrate;

[0036] Figure 3 This is a comparison chart showing the content of volatile compounds with significant differences in the wine samples from the examples and comparative examples of the dual-temperature, dual-state fermentation method for brewing dry red wine according to the present invention. Figure 3 In this context, 'a' represents n-propanol. Figure 3 In this context, b represents ethyl isovalerate. Figure 3 In this context, c represents ethyl isobutyrate. Figure 3 In this context, d represents isoamyl acetate. Figure 3 In this context, 'e' represents ethyl acetate. Figure 3 f represents isoamyl octanoate. Figure 3 g represents ethyl butyrate. Figure 3 In this context, h represents n-hexanol;

[0037] Figure 4 Radar charts of aroma sensory evaluation of wine samples from the dual-temperature dual-state fermentation method for brewing dry red wine according to the present invention, including examples and comparative examples.

[0038] Figure 5 This is a comparison chart of phenolic compound concentrations in wine samples from the dual-temperature, dual-state fermentation method for brewing dry red wine according to the present invention, including examples and comparative examples. Figure 5 In this context, 'a' represents Vit isin, pi not in, FA / AF, A-vF, and AeF. Figure 5 In the text, b represents dimethyl charantin, methyl charantin, charantin, methyl anthocyanin, and anthocyanin. Figure 5In this context, c represents hydroxybenzoic acid, hydroxycinnamic acid, flavanols, and flavonols;

[0039] Figure 6 Sensory radar images of wine samples from examples and comparative studies of the dual-temperature, dual-state fermentation method for brewing dry red wine according to the present invention.

[0040] Figure 7 This is a comparison chart of the polysaccharide and mannoprotein content in wine samples from the examples and comparative examples of the dual-temperature dual-state fermentation method for brewing dry red wine according to the present invention.

[0041] Figure 8 This is a color comparison diagram of wine samples from the embodiments and comparative examples of the dual-temperature dual-state fermentation method for brewing dry red wine according to the present invention. Detailed Implementation

[0042] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0043] The present invention provides a dual-temperature, dual-state fermentation method for brewing dry red wine, comprising alcoholic fermentation, which includes the following steps:

[0044] S1. Inoculate the mixture of grape skins and grape juice with yeast and carry out solid-liquid mixed fermentation until the yeast enters the vigorous fermentation period to obtain the first fermentation product.

[0045] S2. The first fermentation product is divided into a solid-liquid fermentation mixture and a first fermentation broth;

[0046] S3. Perform liquid fermentation on the first fermentation broth separately to obtain the second fermentation broth;

[0047] S4. Mix the second fermentation liquid with the solid-liquid fermentation mixture, and continue fermentation at the temperature of the solid-liquid mixture to complete the alcoholic fermentation;

[0048] Among them, the temperature of solid-liquid mixed fermentation is higher than that of liquid fermentation.

[0049] This invention discloses a dual-temperature, dual-state fermentation method for brewing dry red wine. The alcoholic fermentation process is divided into two parts: solid-liquid fermentation and liquid fermentation. First, solid-liquid fermentation is carried out at room temperature. Then, a portion of the fermented liquid is separately fermented at a low temperature. Finally, the fermentation products from the low-temperature fermentation are mixed with the remaining solid-liquid fermentation mixture, and solid-liquid fermentation continues at room temperature. This method can form an adjustable and controllable "dual-temperature, dual-state" fermentation mode. Temperature changes can effectively improve the aroma, color, and taste of the wine. It not only allows for the timely control of the extraction of anthocyanins and tannins during fermentation but also produces unique aroma components and enhances yeast metabolism, increasing its ester production capacity, thereby strengthening the floral and fruity aromas of the wine.

[0050] Compared to traditional fermentation processes, the present invention allows for variations in fermentation temperature, which is beneficial for the generation and accumulation of aroma compounds. Furthermore, the maceration time is adjustable, allowing the method to be tailored to specific grape varieties and winemaking needs.

[0051] Compared to carbon dioxide maceration, this invention mixes the low-temperature fermented grape juice with the grape skins and pomace again, i.e., performs a "reverse mixing" operation, which helps to accumulate substances such as anthocyanins.

[0052] Compared to cold maceration, the fermentation process of this invention produces more volatile compounds, significantly enhancing the aroma of the wine.

[0053] The method of the present invention is specifically an alcoholic fermentation method. After the alcoholic fermentation of the present invention is completed, conventional malolactic fermentation is carried out to complete the winemaking process.

[0054] In the method of the present invention, the grape pomace used is specifically grape pomace obtained by destemming and crushing.

[0055] The method of this invention is suitable for any dry red wine that requires alcoholic fermentation, and the grape varieties include, but are not limited to, Cabernet Sauvignon, Pinot Noir, Marselan, etc.

[0056] Preferably, the mass ratio of yeast to the volume ratio of the mixture of grape skins and grape juice is 0.1–0.3 g / L. More preferably, the mass-to-volume ratio is 0.2 g / L.

[0057] The specific method of yeast inoculation is as follows: weigh commercially available yeast powder according to the above mass-volume ratio, activate it with 6 to 10 times its mass of softened water at 37°C to obtain a yeast solution, and then add it to the mixture of grape skins and grape juice and stir evenly.

[0058] Preferably, the temperature for solid-liquid mixed fermentation is 26℃~30℃.

[0059] Preferably, the temperature for liquid fermentation is 14℃~16℃.

[0060] Preferably, the liquid fermentation time is 10 to 14 hours.

[0061] Preferably, in step S4, the fermentation time (skin-cap mixed fermentation) continues at the solid-liquid mixed fermentation temperature for 20 to 30 hours.

[0062] Preferably, in step S1, when the yeast enters the vigorous fermentation period, the specific gravity of the fermentation product is less than or equal to 1.070.

[0063] Preferably, in step S2, the volume of the first fermentation broth accounts for 50% to 70% of the total volume of the first fermentation product; wherein, the amount of the remaining solid-liquid fermentation mixture needs to be sufficient for the liquid to be able to be normally circulated and sprayed.

[0064] Preferably, in step S2, the separated solid-liquid fermentation mixture continues to undergo solid-liquid fermentation.

[0065] Repeat steps S2 to S4 until the specific gravity of the fermentation broth is 0.990, then stop the repetition and continue to step S5.

[0066] Preferably, the number of repetitions is 1 to 4.

[0067] The dry red wine of the present invention is brewed using the fermentation method described above, which results in a rich content of flavor compounds and thus exhibits excellent sensory quality.

[0068] The dry red wine of this invention has a significant and rich aroma, as well as a full body, deep color, excellent quality, and good aging potential.

[0069] Example

[0070] This embodiment uses the method of the present invention to brew Marselan dry red wine. The specific steps are as follows:

[0071] The grape raw materials undergo pretreatment such as destemming and crushing before being placed in a fermentation tank to begin alcoholic fermentation. Yeast is inoculated into the fermentation tank, and solid-liquid mixed fermentation begins at a temperature of 28°C.

[0072] When the specific gravity of the fermentation product is less than or equal to 1.070, the fermentation product is divided into a solid-liquid fermentation mixture and a first fermentation broth; in this embodiment, the volume of the first fermentation broth accounts for 60% of the total volume of the fermentation product.

[0073] The first fermentation broth was subjected to liquid fermentation alone to obtain the second fermentation broth. In this embodiment, the liquid fermentation temperature was 15°C and the liquid fermentation time was 12 hours.

[0074] The second fermentation liquid is mixed with the solid-liquid fermentation mixture and fermented at the same temperature as the solid-liquid mixture. After 24 hours of fermentation, alcoholic fermentation is completed, and conventional brewing steps such as malolactic fermentation are carried out to obtain Marselan dry red wine.

[0075] Comparative Example

[0076] This comparative example uses traditional fermentation methods to produce Marselan dry red wine, employing the same grape varieties, quality, and pre-treatment processes. The specific fermentation method involves placing the treated grapes in fermentation tanks and initiating the process. Yeast is then inoculated into the tanks to begin alcoholic fermentation, which continues until completion at a temperature of 28°C.

[0077] The Marselan dry red wines produced in the above embodiments and comparative examples were tested for aroma, color, and taste to compare the quality of the two wines. The specific testing methods, procedures, and results are as follows:

[0078] (1) Aroma quality evaluation

[0079] The concentrations of aroma compounds (volatile compounds) in wine samples from the examples and the comparative examples were analyzed and determined. Three samples of each wine sample were taken as parallel samples for the experiment.

[0080] The heatmap of the concentration changes of each aroma substance is shown below. Figure 1 As shown. According to Figure 1 As can be seen, in the Marselan dry red wines (MLF-BW-1, MLF-BW-2, MLF-BW-3) produced by the dual-temperature dual-state fermentation process of the present invention, the concentrations of volatile compounds, mainly contributing to floral and fruity aromas, such as esters, terpenes, and norisoprene, are higher than the concentrations of volatile compounds in the control group (MLF-CK-1, MLF-CK-2, MLF-CK-3).

[0081] In the wine sample from the dual-temperature, dual-state fermentation of the example, the concentrations of 20 substances with OAV > 0.1 showed varying degrees of increase compared to the comparative wine sample. Specifically, as follows... Figures 2-3 As shown in the figure, "Control" refers to the comparative example, and "Variable Temperature Fermentation" refers to the example. These substances are 1-octen-3-ol, 3-methylthiopropanol, linalool, pentanol, citronellol, octanoic acid, ethyl octanoate, isobutanol, guaiacol, ethyl laurate, n-decanoic acid, n-propanol, n-hexanol, ethyl isovalerate, ethyl isobutyrate, isoamyl acetate, ethyl butyrate, isoamyl octanoate, and ethyl 2-methylbutyrate. The concentrations of 3-methylthiopropanol, octanoic acid, isobutanol, n-decanoic acid, n-propanol, ethyl isovalerate, and ethyl isobutyrate in the dual-temperature, dual-state fermentation group samples were 1.4 to 1.5 times higher than those in the control group samples.

[0082] Sensory evaluations were conducted on the dry red wines produced using two different fermentation processes in the examples and comparative cases. The results are as follows: Figure 4 As shown in the figure, "Control" refers to the comparative example, and "Variable Temperature Fermentation" refers to the example. It can be seen that the wine sample made using the dual-temperature dual-state fermentation process has a richer aroma of fresh fruit than the sample made using the traditional process, while the animal, herbal, earthy, and dried fruit flavors are reduced.

[0083] The experimental results above show that the dual-temperature, dual-state fermentation method of the present invention can significantly increase the content of the above substances, thereby improving the aroma and quality of dry red wine.

[0084] (2) Color quality evaluation

[0085] The wine samples from the examples and comparative examples were tested using the CI ELAB method, and the results are shown in Table 1.

[0086] Table 1. Effects of different winemaking processes on wine color parameters

[0087]

[0088] The content of anthocyanin derivatives in the wine samples of the examples and comparative examples was determined and compared. The results are as follows: Figure 5 As shown, the legend in the figure refers to the comparative example "Control" and the example "Variable Temperature Fermentation". According to... Figure 5 As can be seen, in the wine samples after the dual-temperature dual-state fermentation process in the examples, the content of anthocyanin derivatives increased significantly, especially the content of vitamins and acetaldehyde-bridged polymers. The concentration of vitamins reached 28.45 mg / L, which was about 1.33 times higher than that of the control group, thus enhancing the stability of the pigments. The content of auxiliary color components such as flavanols also increased, showing excellent color protection effect, resulting in a deeper color and increased chroma of the wine samples.

[0089] (3) Taste quality evaluation

[0090] During fermentation, the dual-temperature, dual-state fermentation process directly affects the composition and content of phenolic compounds through temperature changes, thus influencing the taste. QDA experiments were conducted on wine samples from the examples and comparative samples, and the results are as follows: Figure 6 As shown in the figure, "Control" refers to the comparative example, and "Variable Temperature Fermentation" refers to the example.

[0091] according to Figure 6As can be seen, the dual-temperature, dual-state fermented wine sample of the embodiment has a higher overall score and a smoother taste compared to the comparative sample. This is related to the increase in phenolic substances and yeast polysaccharides. The wine sample of the embodiment shows an enhanced persistence and finish, reduced bitterness, and better overall harmony.

[0092] Figure 7 This is a comparison chart of polysaccharide and mannose protein content, comparing the polysaccharide and mannose protein content (AF) during alcoholic fermentation and the polysaccharide and mannose protein content (MLF) during the later stages of apple-milk fermentation in both the examples and comparative examples. According to... Figure 7 It can be seen that, compared to the conventional fermentation method in the comparative example, the method of the present invention in the examples has a significant promoting effect on the accumulation of yeast polysaccharide mannoprotein (MP) content, regardless of the fermentation stage. As for glucose polysaccharides (PRAGs) rich in arabinose and galactose, although the content in the examples is lower than that in the comparative example during the alcoholic fermentation stage, its content is significantly higher than that in the comparative example at the end of fermentation.

[0093] The differences in the aforementioned content are related to temperature changes during fermentation. Temperature changes damage the yeast cell walls, leading to the release of more yeast polysaccharides, and also affect the interaction of yeast metabolites, resulting in the release of more glucose polysaccharides, thus increasing the overall polysaccharide content. The smoother and fuller taste is related to the increased polysaccharide content, resulting in reduced bitterness, better persistence, and better overall harmony.

[0094] 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 dual temperature and dual regime fermentation process for the production of dry red wine, including an alcoholic fermentation, characterised in that, The alcoholic fermentation includes the following steps: S1. Inoculate the mixture of grape skins and grape juice with yeast and carry out solid-liquid mixed fermentation until the yeast enters the vigorous fermentation period to obtain the first fermentation product; the temperature of the solid-liquid mixed fermentation is 26℃~30℃. S2. The first fermentation product is divided into a solid-liquid fermentation mixture and a first fermentation broth; S3. Perform liquid fermentation on the first fermentation broth alone to obtain the second fermentation broth; The temperature of the liquid fermentation is 14℃~16℃, and the time of the liquid fermentation is 10~14 hours; S4. Mix the second fermentation liquid with the solid-liquid fermentation mixture, and continue fermentation at the temperature of the solid-liquid mixture fermentation for 20 to 30 hours to complete the alcohol fermentation.

2. A dual temperature and dual mode fermentation process for the production of dry red wine as claimed in claim 1 wherein, In step S1, when the yeast enters the vigorous fermentation period, the specific gravity of the fermentation product is less than or equal to 1.

070.

3. A dual temperature and dual mode fermentation process for the production of dry red wine as claimed in claim 2, wherein, In step S2, the volume of the first fermentation broth accounts for 50% to 70% of the total volume of the first fermentation product.

4. A dual temperature and dual mode fermentation process for the production of dry red wine as claimed in claim 1 wherein, In step S2, the separated solid-liquid fermentation mixture continues to undergo solid-liquid fermentation.

5. The dual-temperature, dual-state fermentation method for brewing dry red wine according to claim 1, characterized in that, Repeat steps S2 to S4 until the specific gravity of the fermentation broth is 0.990, thus completing the alcoholic fermentation.

6. A dry red wine, characterized in that, The fermentation method described in any one of claims 1 to 5 is used for brewing.

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