I heard that the various tastes of red wine include sweet, sour, bitter, astringent, etc. I would like some specific information.

The following is a part of an article about the taste of wine, transcribed for you:

Chapter 4 Taste and Taste Analysis of Wine

Section 2 Wine Flavor substances and their taste

There are a variety of taste substances in wine, which cause people to taste sweet, salty, sour, bitter, etc.; when these taste substances are combined, different proportions and concentrations Changes can also produce taste sensations such as freshness and astringency. ?

4.2.1 Sweet substances and taste?

The sweet substances in wine are mainly sugar, alcohol and glycerin. They are the elements that contribute to the wine’s taste characteristics of softness, body and roundness. ?

4.2.1.1 Sweet substances in wine?

The substances in wine that can make people feel sweet mainly include sugar and alcohol. ?

Sugar: derived from grape berries; found in semi-dry to sweet wines, and also in small amounts in dry wines. ?

Alcohol: It is a fermentation product and is formed during alcohol fermentation.

The main one is ethanol, and other alcohols are about 0.5%. Alcohols have complex and special smells and tastes, and are the carriers of wine aroma components.

Sweet substance sugar: Glucose: dry wine contains 0.2-0.8 g/L; other wines can reach 30g/L

Fructose: dry wine contains 1 -2g/L; other wines contain 60g/L;

Arabinose: 0.3-1g/L;

Xylose: 0.05g/L.

Alcohol: ethanol

Higher alcohol: propanol, butanol, isobutanol, amyl alcohol, isoamyl alcohol, etc.;?

Polyol: glycerin , 2.3 Butanediol, arabitol.

4.2.1.2 What is the taste of sweet substances in wine?

--What are the tastes of different sugars?

--What are the tastes of different alcohols? Differences?

--Ethanol has a dual impact on the taste of wine?

1. Ethanol: mainly comes from the alcoholic fermentation of sugar in grape juice. Its formation is affected by the sugar content of raw materials, yeast types and fermentation conditions. The ethanol content of wine is shown in Table 4-1.

Table 4-1 Chinese wine standards for ethanol content

Project requirements

Alcohol content (20℃) Sweet and aromatic wines 11.0-24.0

% (V/V) Other types of wine 7.0-13.0 Note: The alcohol content is within the range of the above table, the allowable difference is ±1.0% (V/V), 20℃. ?

Ethanol has a complex taste with both taste and mucosal reaction. Therefore, ethanol has a dual impact on the taste of wine: on the one hand, the sweetness of alcohol itself and its ability to significantly enhance the sweetness of sugar can enhance the thickness of wine; the heat and irritating sensation caused by alcohol The comfortable harshness not only complements the taste of the wine itself, but also integrates with other qualitative characteristics to make the wine rich and plump. It should be noted that mellowness and fatness are related to a sufficiently high alcohol content, and can only be clearly displayed when the alcohol content is higher than 11% (v/v). If the ethanol content is less than 10% (v/v), the wine will have a bland taste and will not have fat characteristics. On the other hand, when the alcohol content is too high, if the content is higher than 14%, the "alcohol taste" will be obvious. The undesirable taste of ethanol manifests itself in the form of strong, unpleasant heat, harshness, and bitterness.

Therefore, if the wine is too high in alcohol and creates an imbalance, it will reduce the thickness of the wine and make it thin. The sweet taste of ethanol can be learned through "training". ?

2. Glycerin: a by-product formed during alcohol fermentation; its formation is related to raw materials, yeast, and fermentation conditions. The glycerol content in wine is 5-15g/L. Wines made from grapes suffering from noble rot have a high glycerin content (more than 15g/L). Glycerol has almost the same sweetness intensity as glucose. On the palate, the sweetness of glycerin is immediately apparent; it enhances the body of the wine and gives the wine a soft, fat mouthfeel character. ?

3. Glucose and fructose: Glucose and fructose come from grape berries.

When grape berries are fully ripe, the ratio of fructose to glucose finally approaches 1. During alcoholic fermentation, since yeast preferentially utilizes glucose, the fructose/glucose ratio gradually increases; at the end of fermentation, the sugar in the wine is mainly fructose.

The total sugar content of wine is shown in Table 4-2. ?

Table 4-2 Chinese wine standards for total sugar content

Project requirements

Total sugar (measured as glucose) g/L still dry wine ≤4.0

Semi-dry type 4.1-12.0

Semi-sweet type 12.1-50.0

Sweet type ≥50.1

Dry flavored ≤ 50.0

Sweet and aromatic ≥50.1

Sparkling sparkling wine natural ≤12.0

Absolutely dry 12.1-20.0

Dry Type 20.1-35.0

Semi-dry type 35.1-50.0

Sweet type ≥50.1

Different sugars have different sweetness intensities. Suppose the sweetness of sucrose is 100, then the sweetness intensity of different sugars is: the sweetness of fructose (173)>sucrose (100)>glucose (74). Therefore, the wine obtained by artificially stopping fermentation is sweeter than the wine sweetened with grape juice. ?

Sugar is the substance that gives wine its sweetness. Its effect on the taste of wine is the same as the sweet effect of alcohol and glycerin, making the grapes round, integrated, smooth and plump. ?But when there is an imbalance between sugar and other substances, the wine will be weak (low acidity, low alcohol content) or sweet (too much sugar). ?

4.2.2 Sour substances and taste?

The appropriate amount of sour substances in wine is a factor that contributes to the taste characteristics of wine such as crispness and freshness (dry white, fresh red).

Acidity that is too high will make people feel that the wine is rough, pungent, stiff, and sour; acidity that is too low will make people feel that the wine is weak, boring, and flat. When acid and other components are out of balance, wine appears thin, dull, and short-flavored. ?

4.2.2.1 Sour substances in wine?

The substances in wine that can make people feel sour are a series of organic acids that exist in a free state (these substances that exist in a free state Organic acids, which make up the total acidity of wine).

There are 6 main types of these organic acids, divided into two categories:?

Tartaric acid

Original from grape berries

Malic acid< /p>

Citric acid

Succinic acid

Derived from fermentation (formed by alcoholic fermentation and bacterial activity)

Lactic acid

Acetic acid

Different organic acids in wine have different sourness, and the strength of the sourness also changes due to different conditions. ?

--When the concentrations are the same, they are arranged in order of sourness:?

Malic acid>tartaric acid>citric acid>lactic acid?

--Under the same pH value, the order is:?

Malic acid>lactic acid>citric acid>tartaric acid

So, in terms of taste, malic acid It is the most sour acid in wine.

In addition, the sourness of wine is mainly affected by total acidity, which is much greater than the PH value. For example, if we add water to wine to reduce the total acidity without changing the pH value, the acidity of the wine will be significantly reduced.

4.2.2.2 What is the taste of sour substances in wine?

1. Tartaric acid: derived from grape berries. During the ripening period of berries, the temperature needs to reach 35°C for tartaric acid to be converted. Tartaric acid is very sour and tastes harsh and rough. It cannot give people a sense of comfort in wine, causing the wine to have a rough sour taste in the aftertaste. ?

2. Malic acid: Its taste is green and astringent. If the wine contains too much malic acid, it means that the grapes are not ripe properly.

3. Citric acid: its taste is fresh and cool. The International Wine Organization stipulates that the citric acid content in wine cannot exceed 1g/L.

4. Succinic acid: The fermented product has a special taste, and the sourness you feel when you first eat it is lighter than the previous ones. Then the taste becomes thicker, first salty and then bitter, and can trigger salivation. Succinic acid is the most complex substance in wine. It can make wine rich in flavor and enhance its mellowness, but sometimes it can also cause bitterness.

?

5. Lactic acid: The acidity is weak, just slightly sour and slightly frankincense. ?

6. Acetic acid: If it smells like vinegar, it often means acetic acid disease caused by acetic acid bacteria. Pungent acetic acid and its derivatives destroy the freshness and purity of wine. If excess acetic acid and ethyl acetate are formed in wine, it is characterized by a rancid smell and mouthfeel.

At the beginning of the illness, when the acetic acid formed in the wine is still small (200-300mg/L), the impact on the senses is relatively small; when the acetic acid reaches 700-800mg/L, although the smell is very small , but can have a vinegary taste. ?Derivatives of acetic acid are pungent. Especially ethyl acetate, when the amount reaches 150-180 mg/L, has an obvious rancid smell and spicy, hot taste, making the wine sour or rancid, becoming hot, making the wine appear sour in taste and smell. , causing a sharp tingling sensation in the mouth, which is different from that caused by alcohol. Therefore, acetic acid and its esters have a greater impact on wine than acetic acid. ?

"Volatile acid is always a sign of poor fermentation management and storage management. It also destroys the aroma and taste of wine."

4.2.3 Salty substances and taste?< /p>

4.2.3.1 What are the types of salty substances in wine?

The salty substances in wine mainly come from grape raw materials, soil and technological processing. They are inorganic salts and a small amount of organic acid salts. Their content in wine is 2-4g/L, which varies depending on the variety, soil, and wine type. ?

1. Cations in wine:

Wine contains a variety of cations, the main ones of which are potassium, sodium, calcium, magnesium, and iron (Table 4-3). These ions mainly originate from the soil and enter the wine through raw materials and processing equipment.

Table 4-3 Cation content in wine (mg/L)

Type Potassium Calcium Magnesium Iron Copper

Content 1148 238 80 1.84 0.1

2. Anions in wine:?

The anions present in wine include bromide, phosphate, sulfate, chloride, etc. (Table 4-4). Table 4-4 Anion content in wine g/L

Sulfite bromide chloride sulfate phosphate

0.1～0.4 0.1～0.7 0.02～0.2 <1 0.07～1

3. Neutral tartrates:?

The neutral tartrates in wine mainly include: neutral tartrate, hydrogen tartrate, neutral malate, hydrogen malate Salt, neutral succinate, hydrogen succinate, lactate, etc. ?

4. There are also some trace elements: fluorine, silicon, boron, bromine, zinc, manganese, copper, lead, cobalt, lithium, etc.

4.2.3.2 What impact do salty substances have on the taste of wine?

1. From the perspective of drinking, most inorganic salts are essential elements for human nutrition. ?

2. The salty substances (salt) in wine participate in the taste composition of wine, and they can enhance all other tastes to varying degrees. But different salty substances have different effects on the taste of wine:?

--Some can enhance the refreshing feeling of wine. For example, potassium hydrogen tartrate not only has a salty taste, but also has a sour taste.

--But if you add salt to wine, such as chloride or sulfate, it will only reduce the palatability of the wine.

--Potassium salt also has a certain bitter taste, which can enhance the unpleasant taste. ?

3. Salty substances (inorganic salts) vary due to different varieties, soil, and techniques. ?

--Calcium: comes from soil, in addition to calcium carbonate used to reduce acid, and filtration, auxiliary litter and clarifiers such as bentonite. Calcium in wine mainly exists in the form of calcium tartrate and calcium oxalate. ?

--Potassium is affected by variety, ecological conditions and harvest period. After fermentation and aging, due to the reduced solubility and precipitation of potassium hydrogen tartrate, the potassium content decreases. Generally, the content of white wine is lower than that of red wine. ?

--Magnesium: Generally present in an amount of 50-165 mg/L, the content in juice is greater than that in wine. The magnesium content may have an important impact on the stability and sourness of tartrate. ?

--Iron: The iron in wine mainly comes from soil and processing equipment.

When the iron content is greater than 8 mg/L, if the pH value, tannin, and phosphoric acid content are appropriate, it will cause iron decay in wine. my country stipulates that the iron content in wine cannot exceed 10 mg/L. ?

--Copper: Copper, like iron, can cause wine turbidity, affect yeast activity and reduce wine quality. When the copper content is higher than 0.5 mg/L, copper-related turbidity may occur in wine. Under normal circumstances, grape juice and new wine contain very little copper, about 0.1-0.3 mg/L, and wine rarely exceeds 0.5-1.0 mg/L.

4.2.4 Bitterness, astringency substances and taste?

4.2.4.1 Bitterness, astringency substances in wine?

Bitterness and astringency in wine Flavor substances are mainly phenolic compounds, such as tannins, phenolic acids, and flavonoids. Due to its nutritional, disease prevention, and treatment functions, it can increase the drinking value of red wine.

1. Tannin:

Tannin is composed of colorless anthocyanins derived from the seeds and peel of grape berries. The fruit stems also contain a large amount of colorless anthocyanins. Another source of tannin is artificially added (tannin processing) or leached in oak barrels.

The taste of tannin is related to its degree of polymerization. According to the taste performance of tannins, they can be divided into the following categories:?

High-quality tannins: derived from ripe berries of fine and valuable grape varieties. Shows good structure and richness in mature wines.

Bitter tannins: derived from common grape varieties and found in some wines with very low acidity. ?

Sour tannins: found in lean, pungent wines. ?

Rough tannins: tannins contained in raw and pressed wines. ?

Wood tannin: Tannin derived from oak barrels. ?

The tannin content in red grapes is about 1-3g/L. There is a certain relationship between the total tannin content in white wine and the intensity of astringency. However, some aged wines, although they have higher tannin content, have lost their astringency and their taste has become harmonious and soft. In aged red wines, these compounds give the wine a brick red color, thus replacing the free anthocyanins. Bright red. ?

2. Phenolic acid: Phenolic acid exists in grape berries in the form of ester, and is hydrolyzed into free acid when exposed to alkali. During the brewing and storage process, part of it will be slowly hydrolyzed. Therefore, both free and bound phenolic acids are often found in wine. ?

3. Flavonoids:

Flavones are a type of pigments that have a chemical structure similar to anthocyanins and are found almost everywhere. They are yellow crystals. The content of flavonoids in wine is small. The darker color of white wine is mainly caused by the darker color of flavonoid polyphenols. Some flavonoids (such as d-catechin, hesperidin) have vitamin P-like effects. Can reduce blood vessel fragility and abnormal permeability.

4.2.4.2 What is the taste of bitter substances?

The taste of the above-mentioned polyphenolic compounds is very complex. Their bitterness is often combined with astringency (sharpness). The complex taste of wine Taste is mostly associated with their presence. The difference in taste between red wine and white wine is caused by these phenolic substances. ?Red wine, rosé or white wine, can all exhibit a surprising bitterness in the aftertaste. In addition, the persistence of wine taste is often based on bitterness. Some red wines will exhibit bitterness that becomes a defect, that is, the bitterness is too prominent and dominates the aftertaste.

Tannin is the muscle that makes up wine. High enough tannin content can make the wine thick, plump, rich, structured, abundant and long-flavored. It is the guarantee of wine’s storage characteristics. However, too much tannin can make the wine stiff, rough, and heavy. ?

The bitter taste of tannin is more prominent in slightly alkaline or neutral solutions. Under the acidity conditions of wine, the bitterness of tannins is impure and confused with astringency. Astringency (sharpness) is often the main manifestation, and the bitterness is even masked by astringency?

In high-quality products In red wine, tannin quality is closely related to aroma quality, and elegance of taste and elegance of aroma always appear together. During the maturation process of wine, high-quality tannins appear and become stronger as the mellow aroma appears. This type of tannin not only softens, but also participates in the composition of the mellow aroma. on the contrary. Rough and impersonal wines are inferior wines, which generally originate from areas with poor growing conditions for inferior grape varieties.

?

4.2.5 Effect of carbon dioxide on sensory quality?

At the end of fermentation, the CO2 concentration can reach 2g/L. When bottling, the concentration should be less than 100mg/L. Because the taste of CO2 is difficult to coordinate with the tannin structure of red wine. ?

The CO2 produced during the fermentation process is basically saturated in the newly brewed wine. Due to the aging and processing of wine, it is impossible to completely remove CO2, so even old wine still contains a small amount of CO2. Therefore, CO2 can be regarded as a normal component of wine. (At the end of fermentation, the CO2 concentration can reach 2g/L. When bottling, the concentration should be lower than 100mg/L.) CO2 is soluble in wine, but it is volatile, so its content gradually decreases in the wine , especially when the wine comes into contact with air, the amount of loss is greater. The aging method also affects the CO2 content. For example, the CO2 content of wine stored in large-capacity sealed metal containers is much higher than that of wine stored in small wooden barrels, while there is no CO2 loss when stored in bottles. Therefore, at the time of consumption, the CO2 content in wine varies greatly and is in an uncontrolled state in most cases. We can completely remove or add part of the CO2 through appropriate methods. Keep its content within the optimal range. ?

CO2 content has an important impact on the sensory quality of wine. Depending on the CO2 content and the type of wine, CO2 can have completely opposite effects. ?

1. In aqueous solution, as long as its concentration reaches 200mg/L, we can feel its simple slightly sour taste. ?

2. If the concentration increases, a pinprick sensation can be produced on the surface of the oral cavity mold due to its release. It is through this pinprick sensation that we identify CO2. But in wine, only when the CO2 content is higher than 500mg/L can you feel its acupuncture sensation.

3. Although the lower CO2 content cannot be perceived, it plays an important role in the balance of the wine:?

--Below the concentration that causes a pinprick sensation, CO2 behaves as an acidifier in wine, participating in the formation of the impression of acidity and intensifying this impression. ?

--CO2 can enhance the unbalanced impression of a sour or lean wine. And these wines may be balanced if they don't contain CO2;?

--On the contrary, CO2 can make bland wines with too low acidity fresh and refreshing. For example, the taste quality of some dry white or semi-dry white wines with too low acid content can be improved by 500-700mg/L CO2. But if the acid content of wine reaches 5g/L (H2SO4), adding CO2 will only reduce its quality, because it already contains enough acid.

--CO2 can enhance the taste of tannins and weaken the sweetness. 400-500mg/L CO2 can improve the quality of fresh red wine with low tannin content. But for red wine that should be matured in the bottle, its CO2 content should be lower than 200mg/I, or even preferably lower than 100mg/I. Because for this type of wine, CO2 can reduce its softness and enhance the roughness of the tannins. Similarly, for liqueurs and sweet wines, the lower the CO2 content, the stronger the fatness. ?

Ribereau-Gayon's research results show that wine tasters are more sensitive to changes in CO2 content than to changes in acidity. He artificially adjusted the CO2 of the same red wine to three groups of 20g/L, 360g/L and 620mg/L, and then invited 50 tasters to taste them in any order. The results are: ?

--73% of the tasters identified the pinprick sensation produced by the wines of the third group on the tip of the tongue; ?

--53% of the tasters distinguished Out of the first two groups of wines, although their CO2 content did not produce a pinprick sensation.

The same group of tasters tasted the same wine with total acid artificially adjusted to 3.3g/L, 3.8g/L and 4.5g/L (H2SO4).

The results are:?

--38% of the tasters did not give any correct answers;?

--32% of the tasters ranked the three groups of wines Arrange in order of total acidity.

4.2.6 What are the taste changes of wine in the mouth?

Wine contains a variety of taste substances, which have sweet, salty, sour, bitter and other flavors respectively; they make people produce There are four basic tastes: sweet, salty, sour, and bitter. ?Due to the different sensitivity and reaction speed of the tongue area to the above-mentioned substances, the changes in the mouth after the wine is entered and the stimulation it gives people are also different. ?During the tasting process, it is very important to analyze the alternating changes in various flavors in the mouth after the wine enters the mouth to understand its flavor composition and taste quality.

1. When the wine enters the mouth?

The main feeling is sweetness and softness?

↓?

2. In the mouth feeling changes. ?

(A change can have different situations)?

↓?

For softer new wines or in other cases, certain modifications?

For high-quality wines that have matured well, the comfort of the wine will decrease:?

The sweetness intensity in the mouth will decrease quickly

The feeling lasts longer. The sourness also appears quickly and intensifies.

(Such a wine is said to have a long taste) (Such a wine is said to have a short taste)?

↓?

3. Aftertaste (tail taste) (in the last few seconds of tasting)?

The bitterness associated with sourness appears and intensifies. ?

If the wine is coarser, its bitterness will dominate the aftertaste. ↓?

4. Aftertaste (the feeling after swallowing or spitting out the wine)?

The persistence of taste and aroma?

5. The gradual disappearance of the feeling Aftertaste