Baijiu tasting: Why is Baijiu bitter?
When it comes to the bitterness of alcohol, I believe you will think of beer. It is normal for beer to have a bitter taste, mainly caused by hops.
But the bitterness of Baijiu is problematic. So, what is the reason for the bitter taste of Baijiu?
The acidity, sweetness, bitterness, spiciness and saltiness in Baijiu are closely related to the quantity ratio of various trace components such as acids, esters, aldehydes, ketones and phenols. If the ratio is appropriate, the bitterness will not appear, but if the ratio is not balanced, there will be bitterness.
At the same time, it is also closely related to the raw materials, process conditions, and operational management used by each factory for brewing.
There are three reasons for the bitter taste of Baijiu.
The imbalance in the proportion of raw materials or accessories caused by unclean or improper selection of raw materials or accessories.
Use moldy raw materials and spoiled koji, if the raw materials or excipients are not thoroughly shelled or steamed, if the steaming is not thorough, use high ester content raw materials.
The Baijiu produced from raw materials with high tannin content has bitter, musty or other odor, which is mainly caused by the decomposition of tannin into some ester compounds during fermentation, because the raw materials used for brewing are polluted by harmful microorganisms, and the fat in the raw materials is oxidized.
In addition, the shell of auxiliary materials contains more pentosan, which will produce furfural with scorched bitterness under the action of microorganisms, which is one of the reasons why Baijiu brings bitterness.
Too much koji or poor quality koji, unreasonable mix of new and old koji, more shells in raw materials, unreasonable water consumption, large gap in cellar, excessive yeast reproduction, etc. will lead to bitter taste of Baijiu.
Take Maotai flavor Baijiu as an example. Maotai flavor Baijiu has strict control standards for raw materials and koji. For example, Daqu is a high-temperature starter made from wheat, which requires the wheat particles to be neat, free from mold, odor, and pesticide pollution, and kept dry.
If the temperature of entering the cellar is too high, the raw materials or koji are crushed too fine or too thick, the cellar is not tightly sealed, and the dross is stored for too long, Baijiu will have inverted burning, bitter, spicy, musty, etc. during fermentation.
The high temperature of entering the cellar makes it difficult to control the early fermentation temperature, resulting in a sharp increase in early temperature and a high temperature of the waste, which lasts for a long time. High fermentation temperature is conducive to the deamination of amino acids by yeast.
The high temperature of the dregs results in rapid aging of yeast, and the amino acids produced after autolysis increase the content of alcohol and tyrosol. The resulting Baijiu has a serious and lasting bitter taste.