CO2 correction factor for the net contents of containers

A new formula to replace the current EBC formula for the correction of net contents in beer containers for the presence of CO2 has been derived from a bibliographic study that reviews the influence of carbonation on beer density determinations. The study reviews the relationship between beer density and CO2 partial molal volume (PMV) as defined by the American Society of Brewing Chemists (ASBC) (ASBC Methods of Analysis Fills-1 formula) and that given by the European Brewery Convention Analysis Committee (EBC) and shows that in the current EBC equation a CO2 PMV of 0.65 mL/g and a residual CO2 content after degassing of 0 v/v or % (m/m) is used. Experimental determination of CO2 PMV gives values of 0.73 +/- 0.01 mL/g for most of the standard European beers as Lager, Pilsener, Premium and Export styles. Residual CO2 levels after decarbonation were quantified for a series of degassing methods and were found to be between 0.20 to 0.50 v/v average 0.40 v/v or 0.08% (m/m). A new equation for determining the CO2 correction was then proposed assuming a PMV of 0.73 mL/g and a beer carbonation level of 0.40 v/v or 0.08% (m/m) after normal degassing. The new formula is recommended for inclusion in Analytica-EBC replacing the current formula.