Fresh gutted medium-sized hake (Merluccius merluccius) (400–500 g) caught in Galician waters either by bottom-set or long-line were purchased from the retail market in Vigo (Spain) during the first 24 h after slaughtering. Hake was transferred to the laboratory within 30 min in expanded polysterene boxes with ice. Once in the lab, three-four specimen were analyzed to assess initial quality. Ice was completely removed and boxes containing hake were sealed and stored under refrigeration conditions during 5–12 days either on an incubator (Model EC-570, Radiber S.A.) for experiments at T ≥ 5 °C, or on a KIDE universal cold room for experiments at T < 5 °C. Four experiments were performed using gutted hake captured by bottom-set nets. In these experiments, the refrigeration temperature was fixed to 1 °C, 3 °C, 5 °C and 7 °C. Samples from experiment at 3 °C were used for validation and the remaining were employed in the parameter estimation procedure. Also, hake captured by long-line gear was stored at 3 °C and used for another validation experiment. A last validation experiment was carried out by using ungutted and gutted hake stored at 2.5 °C. A thermocouple, inserted within the abdominal cavity of one fish, recorded the temperature every 5 min throughout the storage period. Fish (3–4 specimen) were taken out of refrigerated storage on a daily basis (except on weekends). 3–4 samples per specimen were employed for microbiological analyses.