The industrial lager strain (CGMCC No. 4466) was used in the present study. High gravity worts (20 ◦ P, i.e. 12 ◦ P all-malt + 8 ◦ P maltose) and very high gravity worts (24 ◦ P, i.e. 18 ◦ P all-malt + 6 ◦ P maltose) were prepared by adding maltose syrups to the resulting all-malt worts. All worts were sterilized in the autoclave (121 ◦ C, 15 min) prior to fermentation. Proteases supplementations (Neu- trase, Flavorzyme and Protamex, produced by Novozymes A/S) at a final concentration of 100 mg/L were carried out at the begin- ning of fermentations, respectively. Neutrase is a bacterial protease produced by a selected strain of Bacillus amyloliquefaciens with opti- mum activity at pH 5.5–5.7 and 45–55 ◦ C. Flavorzyme is a fungal protease/aminopeptidase mixture produced by a selected strain of Aspergillus oryzae with optimal activity at pH 5.0–7.0 and 50 ◦ C. Pro- tamex is a Bacillus protease complex developed for the hydrolysis of food proteins with optimal activity at pH 5.5–7.5 and 35–60 ◦ C.