the chemical composition of liquor is 98% water and ethanol, and 1% ~ 2% trace components (alcohols, esters, acids and aldehydes and ketones) with fragrance and taste, among which trace components determine the flavor and style of liquor.
liquor blending is the root of the whole liquor production process. The aroma production depends on fermentation, and the aroma blending depends on blending. It is for the traditional liquor technology. The traditional liquor blending method is a means to ensure the consistency of products and the coordination of wines. Different wines with different ages, different cellars and different flavors learn from each other to blend, so as to achieve the purpose of coordinated flavor, outstanding style and uniform product quality. The blending of new-type liquor is often the blending of alcohol, purified water, mixed liquor, solid-state liquor and flavors and fragrances, thus making this kind of product a new-type liquor with uniform quality, harmonious flavor and outstanding style.
Good liquor has a tangy aroma. Many kinds of aroma components in liquor have been identified. At present, there are 136 kinds of aroma components in liquor (9 kinds quantitatively) confirmed by the analytical techniques or means that China can master, including 25 kinds of acids, 42 kinds of esters, 3 kinds of alcohols, 1 kinds of aldehydes, 4 kinds of polyols, 4 kinds of sulfides and free ammonia, and the total number that has not been confirmed is more than 15. According to foreign reports, the aroma-producing components in alcoholic beverages are composed of hundreds of different compounds, including 28 alcohols, 8 acids, 118 esters, 41 carbonyl compounds, 17 acetals, 41 phenols, 11 hydrocarbons, 18 nitrides, 11 sulfides, 17 lactones, 4 sugars, and 11 inseparable compounds.
The content of these aroma components in liquor is very small, but in a proper proportion, liquor has a beautiful and special aroma. The aroma characteristics of various wines are the balanced expression of the amount of its aroma components. No matter how complex the aroma components in liquor are, there is always a main aroma and additional aroma components in every type and style of liquor, which together form the typical aroma of liquor. The sensory quality of liquor aroma should be harmonious aroma, pleasant feeling and prominent main aroma. At the same time, its fragrance overflow, fragrance spraying and fragrance retention are considered. The wine with good fragrance (that is, the wine with good smell), when the wine is poured out, the aroma is overflowing and fragrant, indicating that the wine has more aroma. The wine with good fragrance (that is, imported wine with good fragrance) is full of aroma in the mouth as soon as it is imported, which shows that the wine contains many low-boiling aroma substances. The wine with good aroma retention (that is, the wine with good aftertaste) still has a lingering aroma after swallowing, and it burps after drinking, which also has a particularly comfortable aroma, indicating that its ester content is more, especially high-boiling aroma substances. These aroma components are esters, acids, alcohols and carbonyl compounds.
(1) Esters: The amount of aroma substances in liquor is the largest, and esters have the greatest influence. Esters are volatile compounds with aromatic odor, which are the main substances that constitute the aroma of wine and play a decisive and key role in the formation of typical bodies of various wines.
The average ester content of high-quality liquor, aromatic liquor or famous liquor is .2 ~ .6%, that of Daqu liquor is .2 ~ .3%, and that of ordinary liquor is below .1%, but the total ester content must be not less than .5 ~ .8%.
Liquor generally contains ethyl formate, ethyl acetate, isoamyl acetate, ethyl propionate, ethyl butyrate, ethyl valerate, ethyl caproate, ethyl heptanoate, ethyl octanoate, ethyl decanoate, ethyl laurate, and ethyl lactylate. Esters in alcohol are mainly C1 ~ C14 straight-chain fatty acid esters. Fatty acid esters with 1 ~ 2 carbons have weak aroma and short duration; Esters of fatty acids with 3 ~ 5 carbons have fatty odor, so the content of wine should not be too much; Fatty acid esters with 6 ~ 12 carbons have strong aroma and last for a long time, while fatty acid esters with more than 12 carbons have almost no aroma. The main esters in liquor are ethyl acetate, ethyl caproate and ethyl lactate, and the sum of them accounts for more than 85% of the total esters in liquor. Therefore, it is called the three major esters. The change of ester content in the three major esters has a decisive influence on the flavor of wine. When ethyl acetate is thick, it smells like apples and bananas, and when it is thin, it smells like pears and pineapples. Ethyl hexanoate is spicy and smelly when it is thick, and gives liquor a special cellar flavor when it is thin. Ethyl lactate has the characteristics of no fragrance, and it has a strong sweet feeling to the taste of wine, and it has a astringent taste when it is strong. In common liquor, the ratio of ethyl acetate to ethyl lactate is 2∶1, which are the main components representing the style of liquor. In particular, ethyl lactate is the main aroma of old white dry taste, and even in Luzhou-style liquor with ethyl caproate as the main aroma, ethyl lactate and ethyl acetate occupy an important position. Liquor loses its own flavor without ethyl lactate, but when the content is too high, it is grassy and astringent. In Luzhou-style liquor, besides ethyl hexanoate as the main aroma, there is another main aroma component, namely ethyl butyrate. When ethyl butyrate is strong, it is unpleasant, slightly smelly, and when it is thin, it is rum-flavored. Ethyl butyrate is one of the aroma components of the old cellar in the liquor, and its content should not be too high, otherwise it will bring fat odor.
(2) Acids: Acids are important flavor substances in liquor, and together with other flavor substances, * * * constitute the unique aroma of liquor. The wine with less acid content has weak taste and short flavor; If the sour taste is strong, the wine tastes rough. Proper amount of acid can play a buffering role in wine, which can eliminate the phenomenon of disharmony in taste after drinking. Acid can also promote the sweetness of wine, but the sweetness of excessively acidic wine is reduced, which also affects the taste. Generally, the acid content of high-quality liquor is high, which is about twice as high as that of ordinary liquor and twice as high as that of ordinary liquid liquor. Insufficient acid content will make the wine lack the inherent flavor of liquor, but excessive acid will cause evil odor and reduce the quality of liquor, so some provinces stipulate that the highest acid content in liquor should not exceed .1%. However, the acid content in general liquor should be about .1g/1ml. Among the components of acid in wine, there are mainly acetic acid, caproic acid, lactic acid and butyric acid, and their sum is 9 ~ 98% of the total acid. At the same time, the proportion of different wines is also different. For example, the content of acetic acid is the highest in the total acid of Fen-flavor, and the content of hexanoic acid is the highest in Luzhou-flavor, followed by lactic acid.
The acids in liquor can be divided into volatile acids and non-volatile acids. Volatile acids include formic acid, acetic acid, propionic acid, butyric acid, hexanoic acid and octanoic acid. Formic acid has the strongest irritation, but its content is very small, while acetic acid has strong irritation and high content, which brings pleasant sour flavor and sour taste to the wine. However, if the content is too high, the wine will have a sharp sour taste, while butyric acid has a pit mud flavor and is slightly sweet. Some unsuccessful Luzhou-style wines contain more butyric acid, and the odor is prominent. However, if the content is thin, it may be mixed with other aroma substances, which may also form aroma and aroma components. The caproic acid has pit mud flavor and spicy taste, so Luzhou-style wine must have a certain amount of caproic acid, and if it is excessive, it will have fat odor. Propionic acid smells bitter and sweet, and it is soft to import, and it is astringent in excess. Octanoic acid and fatty acids with longer carbon chains are oily, but the content is not high.
Non-volatile acids include lactic acid, malic acid, gluconic acid, tartaric acid, citric acid and succinic acid. Lactic acid is soft, which brings good flavor to liquor. Lactic acid has a weak aroma, which makes the liquor mellow and strong, while excessive lactic acid has a astringent taste. Succinic acid harmonizes the taste of wine and is beneficial to the body. Limoncello, tartaric acid, has a long sour taste, and makes the wine refreshing, with excessive biting. In short, these nonvolatile organic acids play a role in flavoring and relieving violence in wine. As long as the content ratio is appropriate, people will feel refreshing, smooth and soft after drinking. If the content is too high, it is sour and pungent.
Volatile fatty acids have a peculiar smell from propionic acid. Butyric acid is sweaty when it is too concentrated, while valeric acid, hexanoic acid and heptanoic acid have strong sweaty smell, but this smell will gradually weaken with the increase of carbon atoms, and the odor of octanoic acid is less, but it is weak. Acids with more than 8 carbon atoms have a light acid gas and a slight fat smell.
volatile acetic acid and non-volatile lactic acid are the two most abundant acids in liquor. They are not only important flavor substances in liquor, but also precursors of many flavor substances. The content of acetic acid in general liquor is close to that of lactic acid, while the content of lactic acid in high-quality liquor is greatly increased.
in a word, organic acids have both aroma and taste, and organic acids with less carbon atoms can help fragrance, which is an important fragrance-assisting substance. Acids with more carbon atoms, or non-volatile acids, are important flavoring substances, which play a role in flavoring and relieving violence in wine. However, attention should be paid to their content and the proportional relationship between them.
(3) Alcohols: Alcohols play an important role in liquor. They are the main substances of alcohol sweetness and aroma AIDS in liquor, and also the precursors of aroma substances. Alcohol reacts with acids to form various esters, thus forming the special aroma of liquor.
besides ethanol, there are the following main alcohols in liquor: methanol, propanol, tertiary butanol, sec-butanol, isobutanol, tertiary amyl alcohol, secondary amyl alcohol, isoamyl alcohol, n-amyl alcohol, hexanol, heptanol, octanol, n-butanol, glycerol, isopropanol, 2.3-butanediol, etc. Liquor contains a small amount of higher alcohols, which endow liquor with special aroma, set off the ester aroma and make the aroma more complete. These higher alcohols are both aromatic components and flavor substances in liquor, and most of them smell like alcohol, which lasts for a long time and has stamina, and have a certain effect on liquor flavor. The content of these higher alcohols in liquor and the proportion of various alcohols have an important influence on the flavor of liquor.
these higher alcohols are not good in taste. except for isoamyl alcohol, which is slightly sweet (slightly astringent), all the other alcohols are bitter, and some of them are bitter and long. Therefore, their content must be controlled within a certain range. Too little content will lose the traditional liquor style; Too much will lead to bitterness and bitterness, which will have a bad effect on wine, and it is easy to get drunk. Wine with high alcohol content often brings unbearable bitter and strange taste, which is called "fusel oil taste".
on the one hand, these higher alcohols are harmful components in liquor, and only when they are excessive, they will have a bad flavor. On the other hand, an appropriate amount of higher alcohols is an indispensable aroma and taste component in liquor. If the liquor base is treated very cleanly, and no higher alcohols are added, that is to say, these higher alcohols are absent or very lacking in liquor, the taste of liquor will be very weak. If .3% higher alcohols are added to diluted alcohol, liquor will produce a certain fragrance, so it is also a substance that plays an important role in the composition and style of liquor. The key is that their content must be appropriate, not too much. At the same time, the ratio of fusel oil to acids and esters, as well as the ratio of various types in fusel oil, also have an important influence on the flavor of liquor. If the ratio of alcohol to ester is high, the fusel oil will be unpleasant, while if the ratio of alcohol to ester is moderate, even if the fusel oil content is slightly higher, it will still be unpleasant. The ratio of alcohol to ester in liquor should be less than 1; For example, the ratio of acid: ester: higher alcohol = 1: 2: 1.5 is more suitable. If higher alcohols are higher than esters, the bitter taste of fusel oil in liquid liquor will appear. Conversely, if the higher alcohol is lower than the ester, the taste of the wine tends to be mild and the bitterness is reduced. In addition, if the ratio of isobutanol to isoamyl alcohol in wine is appropriate (1: 2 ~ 2.5), the odor caused by fusel oil can be obviously reduced.
In addition to the above-mentioned higher alcohols, there are also some polyols in liquor, such as glycerol, 2,3-butanediol, cyclohexanol, mannitol and so on, which are sweet substances in liquor. Glycerol has a sweet taste, which makes the wine feel natural. If it is added in a proper amount, it will make the wine feel soft and strong. The sweetness of pentaerythritol (erythritol) is twice that of sucrose, pentanol (arabitol) is also a sweet substance, and hexanol (mannitol) has a strong sweetness, which makes the wine have the sweetness of fruit. These polyols are all viscous liquids, which can bring a full and mellow feeling to liquor.
β-phenylethanol in alcohol is an essential component of liquor flavor, which brings a rose-like fragrance to liquor, and has strong durability, and brings a bitter taste when it is excessive. Alcohols can also combine with fatty acids to form esters, which more or less increase the aroma of wine.
the content of higher alcohols in liquor should be below .3g/1ml, and the total amount of fusel oil should not exceed .15g/1ml according to the physical and chemical indexes of national standards. The higher alcohols mentioned above actually refer to alcohols with -OH groups with more than 2 carbon atoms in the carbon chain. Fusel oil sometimes refers to higher alcohols in a general sense, and the analysis index actually refers to the amount of isobutanol and isoamyl alcohol. Polyol refers to alcohols with more than two -OH groups in the molecule, which are sweet and slightly bitter, and are very stable in wine, making the wine sweet and soft.
Isoamyl alcohol, isobutanol, n-butanol and hexanol are commonly used in blending wine, and a small amount of glycerol and 2.3-butanediol are often added to improve the quality of wine and increase the sense of nature. In addition to the above alcohols, there is also a kind of methanol with only one carbon atom in liquor. Methanol is very toxic, which can cause serious poisoning when eaten in 4 ~ 1g. It is harmful to the blind spots of human nervous system and optic nerve, and it is accumulated in the body, so it is not easy to be excreted. Its metabolites in the human body are formic acid and formaldehyde. The toxicity of formic acid is 6 times greater than that of methanol, and the toxicity of formaldehyde is 3 times greater than that of methanol. Therefore, a very small amount of methanol can cause chronic poisoning, making it difficult for people to get rid of it. According to the national standard, the methanol content in cereal grain liquor should be .4g/1ml, and the methanol content in liquor with dried melons and substitutes as raw materials should be .12/1ml.
in liquor, besides the above alcohols, ethanol is the main component, and ethanol is slightly sweet. The alcohol content determines the alcohol content, and the higher the alcohol content, the stronger the alcohol content. The degree of liquor varies with drinking habits and manufacturing habits in different places. In the north, the alcohol content is above 6 degrees, and in the south, it is 46 ~ 55 degrees. Some people mistakenly think that the higher the alcohol content, the better the quality. This is a wrong view. From the perspective of wine quality, at 53 ~ 54 degrees, the affinity between alcohol molecules and water molecules in wine is the strongest, the alcohol content of wine is good, the taste of wine is the most harmonious, and it is also the most refreshing to people's taste. Maotai liquor has skillfully achieved this point. Hard liquor with high alcohol content is also quite harmful to people, especially if it is drunk all the year round, it is easy to cause chronic alcoholism, and it can cause diseases to nervous system, stomach, duodenum, liver and blood vessels. For the sake of people's health, reducing alcohol content is a problem worthy of attention. Therefore, one of the development directions of liquor is to reduce the alcohol content. Of course, this is still a complicated problem. To reduce the alcohol content, we should not only overcome the turbidity problem caused by low alcohol content, but also have a series of problems to be studied and solved in order not to affect the inherent flavor of liquor. In addition, consumers also have a gradual adaptation process. At present, the alcohol content of Fen-flavor liquor is generally 62-65 degrees, that of Luzhou-flavor liquor is 6 degrees, and that of Maotai-flavor liquor is 52-55 degrees.
(4) Flavor characteristics of carbonyl compounds Aldehydes with carbonyl groups play a certain role in forming the main aroma of wine, and the aroma of wine is closely related to the content and types of aldehyde compounds. Aldehydes have strong fragrance. Aliphatic lower aldehydes have pungent odor, and the length of carbon chain increases, and the fragrance intensity reaches the highest value from C8 to C12, and then decreases sharply with the increase of carbon chain. In liquor, even carbon atoms are more important than adjacent odd carbon atoms.