Abstract The aim of the study was to examine the release of angiotensin-converting enzyme (ACE)-inhibitory peptides in Cheddar cheeses made with starter lactococci and Bifidobacterium longum 1941, B. animalis subsp. lactis LAFTI ® B94, Lactobacillus casei 279, Lb. casei LAFTI ® L26, Lb. acidophilus 4962 or Lb. acidophilus LAFTI ® L10 during ripening at 4 and 8 °C for 24 weeks. ACE-inhibitory activity of the cheeses was maximum at 24 weeks. Cheeses made with the addition of Lb. casei 279, Lb. casei LAFTI ® L26 or Lb. acidophilus LAFTI ® L10 had significantly higher ( P < 0.05) ACE-inhibitory activity than those without any probiotic adjunct after 24 weeks at 4 and 8 °C. The IC 50 of cheeses ripened at 4 °C was not significantly different ( P > 0.05) to that ripened at 8 °C. The lowest value of the IC 50 (0.13 mg mL −1) and therefore the highest ACE-inhibitory activity corresponded to the cheese with the addition of Lb. acidophilus LAFTI ® L10. Several ACE-inhibitory peptides were identified as κ-CN (f 96–102), α s1-CN (f 1–9), α s1-CN (f 1–7), α s1-CN (f 1–6), α s1-CN (f 24–32) and β-CN (f 193–209). Most of the ACE-inhibitory peptides accumulated at the early stage of ripening, and as proteolysis proceeded, some of the peptides were hydrolyzed into smaller peptides.