Why do some beers "go up" after drinking

 The definition of beer "go up" 

★Sometimes, after drinking beer, people will have a "headache" phenomenon, commonly known as "go up", "up head" is a physiological reaction of the human body, and there are many reasons for "up head" after drinking, but beer is in the fermentation process. The trace by-products produced in the

 The main substances that cause "go up"

The main substances that cause the "go up" after drinking are higher alcohols, acetaldehyde, alcohol-ester ratio in beer, and bacterial contamination during fermentation. The above substances enter the brain along with the blood circulation, causing the brain nerve cells to contract and spasm, thus causing discomfort such as bloating and headache—that is, "go up".

★The main higher alcohols in beer are isoamyl alcohol, active amyl alcohol, isobutanol, n-propanol, etc. A moderate amount of higher alcohol can make the wine plump and harmonious in aroma, but the content of higher alcohol in the beer fermented below is too high (such as more than 120mg/L), especially the isoamyl alcohol content exceeds 50mg/L, and the isobutanol content exceeds 10mg/L. When it is L, it will not only have obvious peculiar smell when drinking, but also cause the beer to "go up".

★Acetaldehyde in beer has a great influence on the flavor of beer, and it is one of the main substances that constitute the green flavor of beer. When the acetaldehyde content in beer exceeds this value by 10 mg/L, the beer will have a spicy rotten grass flavor. Acetaldehyde is strongly irritating to the human body. It can stimulate the vomiting nerve center of the human body, causing nausea and vomiting; it can promote the contraction of cranial nerves and cause headaches, and it can also stimulate the peripheral blood vessels of human nerves, especially the capillaries of the face, eyeballs and ears. "Blushing in the face" appears.

★ The ratio of alcohol to ester refers to the ratio of total alcohol to total ester in beer. A high alcohol to ester ratio indicates that the content of higher alcohol is too high, or that the content of ester is too low; reducing the content of higher alcohol may reduce the ratio of alcohol to ester. On the one hand, it is to increase the content of ester, and it is also possible to reduce the ratio of alcohol to ester. Esters are essential flavor substances for beer flavor. Relevant experts have found that the "top" after drinking beer is not only related to the high content of higher alcohol, but also related to the "alcohol ester ratio" in the beer. Generally, it is more appropriate to control the "alcohol-ester ratio" between 3.5 and 4.5:1 after the beer is mature. Because higher alcohols stimulate the cranial nerves in the blood and make them contract, while esters in the blood make the cranial nerves stretch, so alcohol with a low "alcohol-to-ester ratio" is not easy to "go up" after drinking.

★ Contamination of spoilage bacteria and wild yeast during fermentation will significantly increase the content of higher alcohols, especially isoamyl alcohols. Practice has proved that beer that is seriously polluted during the fermentation process will be unpleasant after drinking and will "go up".

 How to prevent beer "go up" 

1. Saccharomyces cerevisiae with low production of higher alcohol is preferred (controlling a reasonable ratio of alcohol to ester);

2. Control the appropriate pH value of wort;

3. Control the appropriate wort concentration;

4. Provide proper wort α-amino nitrogen level and balance of amino acids, magnesium ions, pantothenic acid, biotin and other nutrients;

5. Appropriately increase the yeast inoculation amount and reduce the yeast inoculation temperature;

6. Reduce the fermentation temperature in the main fermentation period, and control the yeast multiplication factor to be less than 4 times;

7. The main fermentation is fermented under pressure, and the pressure is 0.04-0.08MPa (control a reasonable ratio of alcohol to ester);

8. Properly control the fermentation degree of beer;

9. Maintain the freshness of beer;

10. Strictly control microbial contamination during fermentation.