Grain technological quality in winter wheat is influenced by cultivar and growing season conditions. This study characterised selected grain quality traits of four winter wheat cultivars — Glosa, FDL Abund, Python and Promitor — grown at Moara Domnească, Ilfov County, Romania, during the 2022–2023 and 2023–2024 growing seasons. Protein content, wet gluten content and gluten deformation index were determined in composite milled grain samples and expressed on a 14% moisture basis. The two seasons differed in precipitation, with 445.0 mm recorded in 2022–2023 and 623.2 mm in 2023–2024, compared with the multiannual average of 640.6 mm. In 2022–2023, protein content ranged from 12.10% in Promitor to 13.45% in FDL Abund, while wet gluten content ranged from 30.05% in FDL Abund to 40.70% in Promitor. In 2023–2024, protein content increased in all cultivars, reaching the highest value in Python at 15.00%, while Promitor again recorded the highest wet gluten content at 40.85%. Across both seasons, Python recorded the highest mean protein content, Promitor showed the highest wet gluten content and gluten deformation index, while FDL Abund combined above-control protein levels with the lowest gluten-related values. The results suggest that protein content and gluten-related parameters may follow different cultivar-dependent patterns, indicating that the combined evaluation of multiple grain quality indicators may provide a more comprehensive assessment of the technological quality potential of winter wheat.