How to Reduce Higher Alcohols in Homebrewed Beer

The proper amount of higher alcohol in beer can make the beer plump and harmonious in aroma, but if the content is too high, in addition to the obvious peculiar smell when drinking, it will also cause dizziness and headache after drinking, which is commonly known as "top head". , so it is a very important step to reduce the higher alcohol in beer in the beer brewing process. The following DEGONG beer equipment will show you how to reduce the higher alcohol in the beer brewing process.

1. Reasonable control of wort components

The production of higher alcohols increased with the increase of wort concentration, and the content of α-amino acids in wort was very important for the formation of higher alcohols in the fermentation process.

When the amino acid content is low, the yeast will generate the amino acids needed by itself through the anabolic pathway, forming more α-keto acid intermediates, resulting in an increase in the production of higher alcohols; when the wort concentration decreases, the α-keto acid in the wort The content of amino acids is bound to decrease, and the higher alcohols produced during beer fermentation are less.

When the content of α-amino acid is high, the reproduction amount of yeast increases, the metabolic by-products increase, and more higher alcohols are also produced. Generally, the content of α-amino acid in 12°P wort should be controlled at 140-160mg/L, which is beneficial to the overall flavor of beer. , and does not affect the growth and reproduction of yeast.

Therefore, the α-amino acid content of the wort should not be too high, otherwise, more higher alcohols will be formed. Adjusting the appropriate level of α-amino acid in wort is an important technological measure to reduce the content of higher alcohol.

2. The dissolved oxygen content of wort should be stable

The higher the oxygen content in the wort, the greater the proliferation of yeast, the more vigorous the fermentation, and the more the production of higher alcohols will be; on the contrary, the less proliferation of yeast is not conducive to the progress of fermentation.

Generally, the oxygen content in wort should be controlled at 6-10mg/L. Using the wort that is filled in two pots, the last pot of wort can be deoxygenated to prevent the oxygen content of the wort in the fermentation tank from being too high, the proliferation of yeast is too large, and more higher alcohols are produced.

3. Control of wort entering temperature and filling time

After the conical tank is scrubbed, the temperature control of the empty tank should be consistent with the main fermentation temperature to avoid the effect of the tank temperature on the yeast start-up temperature.

The initial inoculation temperature of wort is to control the temperature of the yeast breeding stage in the early stage of fermentation. Generally, it should be 2-3°C lower than the main fermentation temperature, and the full tank temperature should be 1°C lower than the main fermentation temperature. The temperature of the wine body is naturally heated to the main fermentation temperature by the heat generated by the fermentation and metabolism of the yeast, so the cooling temperature of the wort should follow the principle of first low and then high, and finally reaching the full tank temperature.

4. Strictly control the fermentation temperature and pressure

In general, 0.1Mpa pressure has no effect on yeast cells, but has a greater impact on yeast metabolites, cell reproduction and fermentation speed.

The pre-fermentation period does not affect the cell reproduction rate, and the pressure rises when the sugar content drops to 4.5°P. The level of fermentation temperature directly affects how much higher alcohol content is produced.

The higher the fermentation temperature, the faster the fermentation speed and the higher the production of higher alcohols. After using low temperature yeast, the fermentation temperature was reduced to 10°C. The higher alcohol content is controlled within an appropriate range.

5. Strengthen sanitation management to prevent bacterial contamination

Beer fermentation should be carried out in a relatively "pure" environment. Any invasion of miscellaneous bacteria will affect the normal progress of fermentation, especially if the fermentation broth contaminated with wild yeast will significantly increase the content of higher alcohols in beer.