Lagering is the temporary storage of 'young' beer in a barrel or tank, allowing the beer to mature. The beer can then fully ferment and undergoes a second fermentation. The little yeast that is still present and other heavy particles will then settle.

During the lagering process, the beer can ferment and mature at a temperature of 0 to -1 °C. The remaining yeast particles settle and additional carbon dioxide is formed. The remaining yeast particles settle and extra carbon dioxide is formed. Lagering takes 1 to 2 weeks.