Why do some liquor turn yellow? Does liquor turn yellow over time?

Liquor will produce complex glycolysis reaction under the action of microorganisms, some substances in the wine will undergo color reaction, so it will become yellow, with the passage of time, the yellow will become heavier and heavier, under normal circumstances, after a period of storage, it should be pure grain wine or sauce-flavored liquor is more likely to appear yellowing, and the aroma liquor, strong flavor liquor will also appear in this situation, and the fragrant liquor, rice-flavored liquor, will not change and turn yellow, otherwise there will be unqualified productsAt the same time, the yellowing of liquor may also occur due to improper operation in the production process, if this is the case, it is recommended to use activated carbon filtration, but in most cases, yellowing of liquor is normal, so don't worry too much.

The liquor will turn yellow after a long time because the liquor will produce redox reaction and esterification reaction during storage, and the redox reaction is mainly due to the oxidation of some alcohols in the liquor into aldehydes, and the oxidation of aldehydes into acids, and the total ester content of the liquor increases due to the increase of storage time.

There are two reasons for the yellowing of liquor, one is that the normal and qualified liquor with better quality produces light yellow due to a long storage time. The other situation is caused by the fact that the distillation itself is not pure, and the wine contains more impurities.

The former phenomenon is that the liquor will produce redox reaction and esterification reaction during storage, and the redox reaction is mainly due to the oxidation of some alcohols in the liquor to aldehydes, and the oxidation of aldehydes to acids; The slow esterification reaction of alkyd makes the total ester content of liquor increase due to the increase of storage time, and with the increase of ester substances, the color of the liquor will be deepened, and the liquor will produce a richer aroma. In this way, the color of the normally produced liquor will turn slightly yellow with the extension of storage time.

The latter situation is caused by improper operation in the production process, if you want to remove the color, there are two ways for reference: one is to meet the production requirements of the operation process, and then carry out a distillation; The second is to remove color through activated carbon adsorption. Although the effect of using activated carbon adsorption to remove color is very good, it is easy to remove a large part of the flavor substances in the wine.

Please handle it differently for different situations.

The color of the liquor changes to yellow and is closely related to the raw materials selected during brewing, the brewing process, the environment in which the liquor is stored, the time of storage of the liquor and the aroma of the liquor. Theoretically, under the action of microorganisms, complex digestion and polysaccharide reactions will occur in liquor, and some substances in liquor will undergo color reactions, resulting in yellowish liquor. And if the liquor is stored for too long, this color reaction will be more obvious, so tomorrow there is also a saying that the longer the liquor is stored, the more yellow the color of the liquor.

But not all liquor will turn yellow after being stored for a long time. Generally speaking, strong aroma liquor, light aroma liquor, sauce-flavored liquor, and aromatic liquor can easily cause the color to turn yellow, and the common one is Moutai, and the yellowish color of Moutai after being stored for a long time is his signature feature. If the color of Moutai does not appear yellow, it makes people suspect that it is not Moutai.

It is precisely because of this that some merchants do not grasp this characteristic and add caramel color to ordinary sauce-flavored liquor to blend fake Moutai, and some unscrupulous merchants use infused colored substances to increase the yellow color of liquor. The color of sauce-flavored liquor is generally slightly yellow, and after this liquor is stored for a long time, the color of the liquor will become more and more panicked. It is followed by aromatic liquor, strong aroma liquor, and special aroma liquor.

With the increase of storage time and the different storage environment, the degree of yellowing of liquor is also different. What is more obvious is that even if it is the same brand, the same batch of liquor, and the same original box, the degree of yellowing and so on is not the same. Of course, not all flavored liquor will turn yellow, for example, rice-flavored liquor will not turn yellow after being stored for a long time.

There are some fragrant liquors, even if they are stored for a long time, the color of the wine is colorless and transparent.

Reasons for the yellowing of liquor: the iron-containing container will bring a yellowish color to the wine due to the peeling off of the paint; If the ceramic jar or canned wine is too long, the wine will be slightly yellow due to the dissolution of the substances in the jar or jar into the wine; Long-term use of inferior containers or pipeline transportation also causes the color of the wine to be yellowish. In addition, after a long period of natural storage, the wine becomes slightly yellow due to a series of redox reactions between the trace flavor components in the wine.

Relevant knowledge. The color substances produced during the fermentation process are mostly found in soy sauce wine and wine with flavor. Due to the high temperature accumulation and fermentation, the koji and the grain undergo enzymatic browning and non-enzymatic browning reactions, both of which will produce a yellow substance, which will be integrated into the wine body and bring a hint of burnt yellow to the wine.

In addition, due to repeated fermentation and distillation in the brewing process, a very large amount of koji is used, which makes the color content of the grain loss too large, and it may also be due to improper control of the temperature and heat in the process of distilling the liquor, which missteamed the color quality in the grain loss. It is also possible that the temperature is not properly grasped during the saccharification and fermentation process, which may turn yellow soon after storage, or it may be yellow when it is distilled.

Precautions. A lot of liquor is stored properly, and over time, it will indeed become more and more mellow, the taste will become better and better, and the color will turn yellow. But it can't be said that all yellowish liquor is good wine, and this is not an inevitable relationship.