01  – Cheese as a living ecosystem: Understanding variability

Cheese is not a fixed recipe, it is a dynamic microbial ecosystem that evolves from the vat to the shelf. The conference opened by mapping the successive microbial phases: acidification, draining, salting, and ripening, each governed by pH, temperature, and microbial balance. A key takeaway was that the same recipe can produce very different results depending on culture selection and process control. Understanding this cascade is the first step to mastering it.

02  – Acidification: The primary control lever

Poorly controlled acidification doesn’t just affect texture at the early stage; it conditions the different phases such as ripening. Two concrete production defects were examined in detail: post-acidification (chalky core, runny under-rind) and early blowing (swollen or cracked curd). Root causes, diagnostic criteria, and culture-based corrective strategies were discussed.

03  – Microbial competition: Protecting your production

Contaminants are inherent to dairy environments present in milk, water, equipment, air, and even among staff. The conference explored the conditions that enable their development, including factors such as pH, moisture, and temperature, and how these are managed through a combination of rigorous hygiene practices, controlled processing conditions, and the targeted use of protective and bioprotective cultures.

A case study on Listeria monocytogenes highlighted why environmental control alone is not sufficient, demonstrating how microbial barriers can strengthen overall protection.

04  – Ripening flora: A lever for differentiation

Surface and ripening cultures are key tools to steer the final profile of a cheese through three main dimensions: aroma, rind texture, and surface colour. Non-starter lactic acid bacteria (NSLAB) such as Lactobacillus spp. drive flavour complexity and proteolysis, while Propionibacteria contribute to typical aromatic profiles and, in some technologies, to eye formation. Geotrichum candidum plays a central role by initiating rind deacidification, enabling the development of secondary flora, and shaping a uniform, supple rind with specific aromatic notes. Finally, red smear bacteria (coryneforms, Staphylococcus spp., Brevibacterium) define pigmentation, rind typicity, and aromatic intensity. Practical approaches were discussed to reproduce these microbial profiles consistently and adapt them to specific production constraints.

05  – Oxygen management: an underestimated factor

Most surface moulds are strictly aerobic: without oxygen, they cannot develop, even if spores contaminate the product. Oxygen absorbers actively remove residual oxygen from the headspace, dissolved in the product and entering through packaging permeability, down to near anoxia (<0.01%). This inhibits spoilage flora such as moulds or aerobic bacteria, prevents lipid oxidation and aroma drift, and stabilises the product over time without altering its intrinsic composition. Beyond microbial control, this approach enables shelf-life extension without chemical preservatives and can reduce or replace technologies such as modified atmosphere packaging (MAP), freezing, or certain additives, while preserving organoleptic and nutritional quality. It also brings operational benefits such as reduced losses, improved production flexibility, and extended distribution range without modifying the process.

Each topic can be explored further in relation to your specific technology, products, and constraints. Don’t hesitate to reach out.