French start-up tests bacterial spray to shield grapevines from frost

A Strasbourg-based deeptech start-up is developing a bacterial biostimulant designed to help grapevines withstand late spring frost, a climate risk that can wipe out large parts of a harvest and raise costs for growers across Europe.

The company, Pewman, was founded in May 2024 by the Chilean microbiologist Dr. Isaac Bugueno and has been incubated since February 2025 at Quest for Change. It is working on a product built around a naturally occurring microorganism found in extreme environments. The bacterium, named Pseudomonas pewmanensis, is intended to trigger a cryoprotective effect that would make vine buds more resilient when temperatures drop below freezing after bud break.

Early trials in French vineyards have shown signs that treated buds are better able to survive frost episodes. Those results are still preliminary, but they have given the company enough confidence to move ahead with regulatory testing in France with Eurofins, supported by the Grand Est regional government and Bpifrance. Four test groups have been set up with different doses and application schedules, and the treatments were applied during the last week of March. Final results will be assessed at harvest, when the company will be able to measure whether the treatment has had a real effect on yields.

For Pewman, viticulture is the first target market because it is one of the crops most exposed to spring frost. In Champagne alone, some frost events have already cut as much as 40% of production. The company says its broader European market could be worth between 4 billion and 5 billion euros, with vineyards covering about 3.2 million hectares across Europe. It estimates that its product would be applied at a rate of 1.5 to 3 liters per hectare, diluted in several hundred liters of water, at an annual cost of about 200 euros to 300 euros per hectare.

The start-up says it is aiming for its first commercial launch by the end of 2026, pending regulatory approval. That timeline depends on the outcome of the current trials and on the authorization process required before any sale can begin in Europe.

Pewman currently has four operational employees and a broader founding team of about 10 people. The company reported about 65,000 euros in revenue in 2025 from research and development services. It is also preparing for industrial production and is considering setting up a manufacturing unit near Illkirch-Graffenstaden, outside Strasbourg, to support future sales.

The company’s founders say they chose grapes because the crop faces repeated losses from frost and because growers are looking for practical tools that can reduce weather-related damage. Pewman says it plans to extend the technology to other crops vulnerable to climate stress if the vineyard product reaches the market successfully.