Enhancing the Value of Organic Milk

Farming Systems and the Cheese-Making Suitability of Organic Milk: Balancing Farmer Strategies, Technological Processes, and Cheese Quality

Building on insights from the BIOFROM project, URTAL launched the BIOSYLF research project in collaboration with UR ASTER-Mirecourt, UMRF-Aurillac , and a group of organic dairy farmers from the plains of the Western Vosges. These farmers specialize in producing hay milk under the Traditional Specialty Guaranteed "Lait de Foin". BIOSYLF was conducted as part of INRAE’s METABIO MetaProgram, which focuses on scaling up organic agriculture.

The BIOSYLF project, positioned at the intersection of farming activities and cheese-making technologies, pursued two main objectives: (1) to analyze a variety of farming practices and their adaptations to fluctuating environmental resources and (2) to explore innovative cheese-making practices that: (i) enhance the uniqueness and seasonality of organic milk, and (ii) build resilience into cheese-making processes to handle seasonal variations in milk quality. To achieve these goals, the project investigated seasonal changes in the quality of milk (microbiological, physicochemical, and cheese-making suitability) and cheese (microbiological, rheological, and sensory characteristics).

As demonstrated in a previous study, grazing-based organic farming systems are particularly sensitive to environmental conditions such as drought or excessive rainfall. These climatic factors cause fluctuations in the composition of organic milk, affecting cheese-making processes and, ultimately, the characteristics of ripened cheeses.

Milk samples were collected across three periods (spring, summer, and winter) from five participating farms, with three replicates for each period.

The pooled raw milk samples were processed using two cheese-making techniques: cooked pressed cheese (PPC) and uncooked pressed cheese (PPNC). Both techniques were tested with and without the addition of a reductive lactic starter to modulate the milk’s redox potential.

The study tested the following hypotheses: (1) Can the reductive lactic starter enhance the robustness of the cheese-making process while preserving the expression of the milk’s native microflora? (2) If so, does this robustness depend on the cheese-making technique used? The reductive starter was explored as a technological lever to explore how redox modulation could compensate for fluctuations in the composition of organic milk—especially those driven by climatic variability—while ensuring consistent cheese production.

Comprehensive analyses included:

• Physicochemical, microbiological (both cultural and metagenomic), and cheese-making evaluations of milk from individual farms and pooled samples.
• Physicochemical, microbiological (both cultural and metagenomic), rheological, and sensory assessments of ripened cheeses.

An intermediate review was held with all partners and URTAL staff in Poligny on October 6, 2021. Final results (excluding metagenomic data, which are still being processed) were presented during a steering committee meeting at UR ASTER-Mirecourt on October 18, 2022.

The findings will be presented as a poster at the METABIO seminar in Saint-Malo on March 21–22, 2023, and will be discussed in detail in the next episode.

Contact :

• URTAL : eric.beuvier@inrae.fr, odile.rolet-repecaud@inrae.fr
• ASTER : thomas.puech@inrae.fr
• UMRF : celine.delbes@inrae.fr