ISO 27205:2010

Overview

ISO 27205:2010 (IDF 149:2010) defines a standard of identity for industrial bacterial starter cultures used in the manufacture of fermented milk products (yoghurt, sour cream, cultured butter, cheese). It specifies characteristics, grouping, microbiological criteria, quality and food-safety management, labelling and recommended methods of analysis. The standard covers principally lactic acid bacteria (LAB) and also includes bifidobacteria and propionibacteria, but it does not apply to cultures used solely for probiotic labelling.

Key topics and technical requirements

• Scope and definitions
  • Clear definitions for starter cultures, LAB, propionibacteria and bifidobacteria and related terms.
• Grouping of cultures
  • By composition: single-strain, single-species multiple-strain, multi-species.
  • By application temperature: mesophilic (~18–37 °C) and thermophilic (~30–45 °C) starters, with example species listed (e.g., Lactococcus, Lactobacillus, Streptococcus thermophilus).
  • By physical form: liquid, frozen, dried.
• Essential composition
  • Viable cell concentration must meet the minimum specification claimed by the manufacturer; alternative functional tests (acidification, texture, optical density, flow cytometry) may be used where appropriate.
• Microbiological specifications
  • Contaminant limits for product and process hygiene (examples from the standard):
    • Non-lactic acid bacteria: < 500 CFU/g (liquid and frozen); relevant for LAB-only cultures.
    • Yeasts and moulds: <1 CFU/g (liquid/frozen), <10 CFU/g (dry).
    • Enterobacteriaceae and coagulase-positive staphylococci: low-level limits with stricter values for liquid/frozen forms.
    • Salmonella spp. and Listeria monocytogenes: absence in 1 g.
• Quality and food-safety management
  • Requires manufacturers to implement quality systems and HACCP-based control measures to prevent contamination.
• Product information
  • Labelling and technical data requirements to support correct use and traceability.
• Analytical methods
  • Annex A lists recommended methods for assessing compliance (microbiological testing and functional assays).

Applications and practical value

• Provides a harmonized benchmark for:
  • Starter culture manufacturers setting product specifications and shelf-life.
  • Dairy processors selecting and validating starter cultures for yoghurt, cheese and other fermented milks.
  • Quality assurance and regulatory bodies auditing microbiological safety and labelling compliance.
  • Testing laboratories implementing recommended methods of analysis.
• Helps ensure consistent fermentation performance, product safety, and regulatory compliance across the dairy supply chain.

Related standards and provenance

• Published jointly by ISO and the International Dairy Federation (IDF); developed by ISO/TC 34 SC5 and IDF expert groups. This edition replaces earlier IDF guidance and refers to established HACCP and food-safety frameworks for process controls.

Keywords: ISO 27205:2010, bacterial starter cultures, fermented milk products, lactic acid bacteria, starter culture specifications, microbiological criteria, mesophilic, thermophilic, dairy quality management.