Reneris Protein reports 77% casein recovery from discarded milk as fundraising opens

French startup Reneris Protein has opened a funding round after reporting a 77% casein recovery rate from discarded milk, following six processing campaigns conducted with dairy expertise centers. The company is developing a patented process to extract valuable protein from milk rejected because of antibiotic residues, with plans to commercialize the technology through existing dairy infrastructure rather than constructing its own production facilities.

• Reneris Protein reports 77% casein recovery, independently validated following six processing campaigns.
• Its technology targets milk rejected because of antibiotic residues, with technical-grade applications offering an initial commercial route.
• The company has opened fundraising to support commercialization, with ambitions to expand from France into other European dairy markets.

Every year, substantial volumes of milk are removed from the French dairy supply chain before reaching processing facilities. Some contain traces of antibiotics that make them unsuitable for conventional food production, leaving dairy producers with limited options for recovering their value.

Reneris Protein believes the casein contained in this discarded milk represents an opportunity. The Normandy-based startup has developed a process intended to recover the protein for use in industrial applications, while investigating the regulatory requirements for potential food uses.

According to founder Laetitia Tardif, between 450 million and 680 million liters of milk are destroyed annually in France before reaching factories because of antibiotic contamination. These figures have been presented by the company and have not been independently verified for this report.

The potential feedstock is significant, although the volume of recoverable casein will depend on the composition of the rejected milk, collection arrangements and the practical economics of processing it.
Reneris has spent the past several years developing its separation technology. In an October 5 announcement, Tardif confirmed that the company had completed six transformation campaigns in collaboration with dairy expertise centers and achieved a 77% recovery rate validated by third parties.

The company filed a patent application in April 2025 and has since reported reaching Technology Readiness Level 6, indicating that its technology has been demonstrated in a relevant environment. It has also reported validation of industrial drying, an important step in producing casein suitable for transport, storage and use by downstream manufacturers.

Rather than establishing dedicated factories, Reneris intends to license its technology to dairy cooperatives and industrial partners. The approach would allow processing to take place within existing facilities, potentially reducing capital expenditure and avoiding the need to establish an entirely new manufacturing network.

The company has described staged joint development agreements as part of its commercialization strategy, allowing partners to evaluate the process before committing to wider deployment.
Its initial focus is on technical-grade casein, which has established applications outside the food industry. These include adhesives, paper coatings, resins, paints, varnishes and construction materials, where casein can provide binding and other functional properties.

These applications offer a potential route to market without the same regulatory requirements associated with introducing recovered ingredients into food products. However, the suitability of the recovered material for individual industrial uses will still depend on its purity, composition and relevant chemical safety requirements.

The food-grade opportunity presents a different challenge. Milk rejected because of antibiotic residues cannot simply be returned to the human food supply through protein recovery. Reneris would need to demonstrate that its process adequately addresses contamination and that the resulting ingredient meets applicable safety and regulatory standards.

The company has indicated that it is pursuing a consultation with the European Food Safety Authority concerning a potential Novel Food pathway. This does not constitute regulatory approval, and commercial use in food would depend on the applicable legal classification and successful completion of any necessary assessments.

Reneris is initially concentrating on France, which Tardif identifies as Europe's second-largest dairy producer. The company subsequently wants to introduce its technology into other major dairy-producing countries, including Germany, Ireland, the Netherlands and Italy.

The expansion strategy would depend on securing dairy industry partnerships and demonstrating that the process can operate consistently across different facilities and feedstock conditions.

The newly opened funding round is being offered initially to the company's trusted network. Reneris has not publicly disclosed the amount it intends to raise, its proposed valuation or a timetable for closing the investment.

The company has also not released detailed operating costs, casein production volumes or projected revenues from commercial licensing. Those figures will be important in assessing whether the technology can compete with conventional casein supply and established industrial protein alternatives.

For now, the independently validated recovery rate reported by Reneris provides the principal technical milestone behind its fundraising campaign. The next test will be translating those results into operating agreements with dairy processors and establishing a commercially viable supply of recovered casein.

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