Microbiological safety of feta PDO cheese matured in an aged beech wood barrel

The production of traditional feta cheese of protected designation of origin (feta PDO) involves the use of traditional wooden barrels or large tins. Increasingly, studies have highlighted the beneficial role of wooden dairy equipment in enriching milk microbiota and enhancing acidification processes. The present study aimed to assess the hygiene, processing conditions and microbiological quality of feta PDO produced traditionally. Samples were collected at various stages of ripening. These samples included pasteurised milk, biofilm, feta cheese and brine. The present study focused on the hygiene and safety aspects of the production process, including the microbial populations present on the internal surfaces of the wooden barrels used in cheese production. The analysis confirmed that the barrels met safety criteria, as no major pathogenic microorganisms were detected in compliance with legislative standards. The low microbial content of the cheese samples, particularly the absence of Salmonella spp., Listeria monocytogenes and Staphylococcus aureus, reflected excellent hygienic practices throughout the production process. Factors contributing to this outcome included effective heat treatment, proper refrigeration and rigorous hygiene during maturation and storage. On the whole, these findings suggest that feta PDO cheese production follows a well‑established, standardised process that is fully compliant with current national legislation.