ABSTRACT We compared acidified and lactic acid fermented silage approaches for the preservation of blue‐jack mackerel. Silages acidified with formic and propionic acids had stable pH (3.8) and low (19 mg/g N) levels of volatile nitrogen compounds (total volatile basic nitrogen, TVBN), but relatively high (82 g/100 g) final non‐protein‐nitrogen (NPN) values. The silage was fermented with Lactobacillus plantarum LU853, a homofermentative lactic acid bacterium with a high growth (0.51/h) and acidification rate at 37C (optimum temperature), able to grow in the presence of 40 g/L NaCl and to ferment sucrose and lactose. The silages at 37C reached safe pH