Determination of the total oxygen content (dissolved and in the headspace) in filled containers
The bottled or canned beer is brought to 20 °C and mechanically shaken, thereby achieving equilibrium between the oxygen dissolved in the beer and the oxygen present in the headspace (Henry’s and Dalton’s laws). By directly measuring either the oxygen in the beer or in the headspace, the total oxygen can be calculated through referencing a table of values, which includes the headspace volume as a percentage of the fill volume.
Cloudy beers
The shelf-life test involves direct incubation of the untreated, sealed sample with accompanying visual inspection of the biological states of a beverage (slime formation, creamy skin, agglomerates) and a final microscopic analysis.
Filtered beer
Testing for microbiological shelf life involves direct incubation of the untreated sealed sample as well as a visual inspection of the biological condition of a beverage (medium) and a final microscopic analysis in the event of positive visual findings.