Control measures for carbon dioxide in beer

The dissolved carbon dioxide in beer is conducive to the foaming property of beer, giving beer a killing feeling, which is conducive to preventing the oxidation of beer and making the bitterness of beer softer. The production of beer by the high-concentration dilution method can increase production capacity and reduce costs. However, improper control will cause the problem of insufficient CO2 content. CO2 solubility increases due to temperature decreases and storage pressure increases in the late fermentation stage, and CO2 changes due to pressure changes during sake filtration and CO2 supplementation during dilution will cause changes in CO2 solubility.

Expressed by the formula: finished carbon dioxide = dissolved saturation in the fermentation process + carbon dioxide saturated with diluted water + carbon dioxide replenishment in the fermentation broth during the filtration process - filtration loss - packaging loss.

1. Affects carbon dioxide

Solubility factors

The reason for the insufficient carbon dioxide content of beer is due to the insufficient carbon dioxide content of the wine itself and the insufficient saturation of carbon dioxide in the dilution water.

1.1 The relationship between carbon dioxide solubility and temperature: Experiments have shown that the higher the temperature control, the lower the carbon dioxide solubility, and under isobaric conditions, the carbon dioxide content decreases by 0.01% for every 1 degree increase in temperature.

1.2 The relationship between carbon dioxide solubility and wine storage pressure: The size of wine storage pressure directly affects the solubility of carbon dioxide, and the relationship between the two is directly proportional. When the fermentation temperature is 10 °C, the correspondence between the two is shown in Table 2.

1.3 Carbonic acid can react with alcohol to form esters, and the higher the alcohol content. The more converted into esters, the greater the CO2 loss. The correspondence between alcohol content and carbon dioxide content is shown in Table 3.

1.4 The storage time of wine fermentation time is long, the solubility of carbon dioxide is good, the more stable the dissolution, so when the wine is tight in the peak season, it is also necessary to ensure the storage time of the wine, which is not only good for the dissolution of carbon dioxide, but also for the stability of the wine.

1.5 high concentration dilution method production, dilution water carbon dioxide saturation, to strictly control carbonation, the content of carbon dioxide in water should be controlled at 0.35~0.50%. To add CO2, under the condition of low temperature and certain pressure, CO2 is reversed into the wine and quickly forms a tiny air flow, which is mixed with the wine and evenly distributed in the wine.

2. Improve in the production process

Measures for carbon dioxide solubility

2.1 Appropriately increase the pressure of the fermenter during zero storage to 0.13~0.15MPa, and increase the carbon dioxide content in the fermentation broth. The temperature is low in winter, the fermentation wine is long, and the pressure control at each stage can be 0.01~0.02Mpa lower in peak season.

2.2 Maintenance personnel regularly check the tightness of the tank top safety valve, vacuum valve, and various valve gaskets and the condition of the pressure gauge.

2.3 Control tank pressure should consider the change of pressure when yeast is discharged. After the fermentation broth drops to 0 °C, the CO2 content is tested in the laboratory. According to the inspection results, the workshop timely carries out pressure draining and pressure replenishment operations.

2.4 Considering the pressure of the fermenter's own liquid column, the amount of wort fed into each tank is different, and the controlled pressure should also be different.

2.5 The fermentation broth is stored at 0~1 degrees for at least five days to fully dissolve carbon dioxide at low temperature and pressure.

2.6 Increase the carbon dioxide content in deaerated water.

2.6.1 Instead of flushing the sake pipe in the filter room, the sake pipe is flushed by a carbon dioxide adder in front of the sake tank.

2.6.2 From the original partial period of carbon dioxide, to the current whole process of the whole filter wine, the operator is required to reasonably control the opening of the carbon dioxide valve to ensure that the carbon dioxide and sake in the filtration process are fully in contact and evenly mixed.

2.6.3 Strictly control the temperature of the diluted water at 0~2 degrees, and the pressure of carbon dioxide is higher than the pipeline pressure of 0.05Mpa.

2.6.4 In the process of replenishing carbon dioxide, in order to increase the contact area of carbon dioxide with water, venturi tubes are used. The larger the contact area between carbon dioxide and water, the finer the distribution in water, and the longer the contact time, the stronger the adsorption effect of the wine on carbon dioxide, the more carbon dioxide content, and the more uniform it is.

2.6.5 The purity of carbon dioxide added during the filtration process should meet the requirements, and if the purity does not meet the requirements, sometimes the pressure of the sake tank is very high, but the carbon dioxide of the finished wine is not high, indicating that the purity of the gas does not meet the requirements.

2.7 The operator is required to check the carbon dioxide content once when the sake is half a can, and adjust the opening of the carbon dioxide valve again according to the carbon dioxide situation of the first half of the can.

2.8 It is required to control the pressure of the empty tank at 0.10~0.13MPa, and the sake tank is too low to make a large amount of carbon dioxide overflow from the liquor. Before the filtration begins, the sake tank should be empty and backpressed to prevent the gushing of the can, which will lose a large amount of carbon dioxide when the filtration begins.

2.9 Control the temperature of sake before filling to 0~4 degrees, if the temperature is too high, the dissolved carbon dioxide is easy to escape.

2.10 When the sake tank is full, if the operator detects that the carbon dioxide content meets the standard, the pressure of the sake tank needs to be slowly unloaded to 0.1~0.15MPa, and the pressure must not be quickly relieved, and the carbon dioxide must be strung into the recovery system when the pressure is unloaded, and it shall not be emitted into the air, and the sake will be stable for 12 hours under the pressure of 0.1~0.15Mpa after testing, and the carbon dioxide content of sake will not increase.

2.11 Effect of analysis and detection of sake carbon dioxide reagents on test results:

The reagents that affect the test results are mainly Ba(OH)2, Ba(OH)2 solution has a long use time, repeatedly opening the reagent bottle cap, causing carbon dioxide in the air to enter, producing BaCO3 precipitation, resulting in low carbon dioxide content of the measured sake, and increasing the deviation between the finished carbon dioxide test results. The use of a combination of pressure gauge and reference reagent methods in production reduces the impact of measurement tests on the final result.

2.12 Do a good job of insulating the pipeline, especially the pipe from the sake tank to the filling machine.

2.13 If the pressure of delivering wine is too large, the wine liquid of the wine tank of the wine filling machine is unstable, the wine in the bottle is fast, and it is easy to foam, when the wine bottle comes down from the wine filling machine, due to the sudden decrease in pressure, the phenomenon of drinking will occur.

2.14 Bottles washed by the bottle washing machine should have low alkali residue. The outlet temperature of the bottle washing should be low, and the bottle temperature should be high, which will cause the wine temperature to rise and make carbon dioxide lost.

2.15 The filling system should be stable, and during operation, it should not shake to cause the loss of carbon dioxide.

2.16 The reasonable arrangement of the pipeline ensures the finish of the inner wall and does not produce turbulence.

3 Conclusion

Carbon dioxide is closely related to the quality and taste of beer, and the more stable carbon dioxide is in beer, the better it is for the quality of beer. In order to ensure that the carbon dioxide content index in the finished wine is more stable and uniform, strict control is carried out from the above aspects, so that the carbon dioxide content of the final product can be controlled to 0.48%~0.52%.