Ageing is a key post-mortem process affecting beef quality; however, alternative fat-coating methods remain insufficiently understood. This study compared wet ageing (WA), dry ageing (DA), butter ageing (BA), and tallow ageing (TA) in terms of their effects on physicochemical, technological, and sensory characteristics. Longissimus lumborum muscles from Fleckvieh heifers were aged for 50 days under controlled conditions: WA samples were vacuum-packed, DA samples were stored bone-in, and BA and TA samples were coated with butter or rendered tallow. Instrumental quality analyses and descriptive sensory evaluation by a trained panel were performed. Ageing significantly improved tenderness in all treatments, reducing the Warner–Bratzler shear force (WBSF) from 55.8 N in fresh meat to 35.1–39.9 N after 50 days of ageing. However, tenderness did not differ significantly among the ageing methods. Meanwhile, pH increased and myofibrillar fragmentation progressed during ageing. The BA and TA samples exhibited higher scores for sour and atypical sensory notes. DA samples were also perceived as juicier than the other treatments. Overall, although all methods produced acceptable tenderness, conventional ageing, particularly dry ageing, provided superior sensory quality. Utilising butter or tallow coating during beef ageing did not enhance flavour development, and may negatively affect sensory profiles.