In order to be in line with international standards, the national standard GB4927-200 1 changed the measurement unit of beer alcohol content from [%(m/m)] to [%(v/v)]. Therefore, the national standard for beer analysis (GB/T4928-200 1) retains the gravimetric method and adds the volumetric method to the arbitration method for alcohol determination. The alcohol content [%(m/m)] obtained by gravimetric method is used to calculate the original wort concentration, but it cannot be used to represent the alcohol content [%(v/v)] of beer, while the alcohol content obtained by volumetric method is a sample.

Alcohol [%(v/v)]. Adding volumetric method not only means adding a distillation weighing process to the old standard, but also requires more stringent requirements for washing, drying and constant volume temperature of 100 ml volumetric flask than gravimetric method. Obviously, the workload has obviously increased, and the determination time of each sample has also increased by 40-70 minutes, which has affected the timeliness of service for production. So I sorted out the comparison table of relative density (specific gravity) and alcohol content (alcohol content) to provide a quick look-up table method for the majority of beer chemists.

In this method, the volume percentage of alcohol content [%(v/v)] can be obtained by directly looking up the table with the relative density obtained by gravimetric method instead of volumetric method. The following example illustrates the usage:

The relative density of the distillate of the sample (20℃) is 0.99539 by gravimetric method, and the alcohol content of the sample is 3. 17[%(v/v)] directly from the fifth column of the table.

After more than one year's trial, it is proved that this method is accurate, reliable, convenient and feasible, and it is an important tool for beer analysis.