Discovering Yeast in Paradise
In the heart of the Indian Ocean, on the island of La Réunion, sits a small craft brewery with a big idea. More than 500 miles (800 km) east of Madagascar, this French island is a true tropical paradise — home to pristine beaches, towering waterfalls, highland plateaus, lush rain forests, and dramatic volcanic mountain ranges. For local wildlife and plant life, it’s an extraordinary playground.
Tucked away in the hills above the capital city of Saint-Denis, two college friends and I founded Brasserie Artisanale Dalons in 2018 after years of brewing together in a garage. From those humble beginnings, the brewery has built a strong reputation across the island for its hop-forward beers and vibrant fruit-forward creations. But this isn’t a story about the brewery’s beer. From the very beginning, we shared a larger vision. Living on an island means that most brewing ingredients must be imported. Determined to gain greater independence and reduce our environmental footprint, Dalons launched an ambitious R&D project to discover and isolate a native strain of Saccharomyces cerevisiae on the island.
La Réunion’s biodiversity offered the perfect starting point. In August 2023, we traveled to the highlands of the island, more than 3,200 feet (1,000 m) above sea level, to the region known as Plaine des Cafres. There, we collected samples from a yellow endemic flower growing in the wild. That single sample would ultimately lead to the isolation of a remarkable yeast strain.
Back in the brewing lab, we began a meticulous microbiological isolation protocol. The process included selective culturing on YPD and Sabouraud media, incubation at 82 °F (28 °C), morphological observation, biochemical testing, and fermentation trials on sterilized wort. Our goal was simple but challenging: Identify one unique strain among multiple active colonies.
After extensive testing, one candidate clearly stood out. It demonstrated strong fermentation kinetics, solid alcohol yield, balanced flocculation, and — most importantly — a distinctive aromatic profile. Wild yeasts often struggle to match the performance of commercial brewing strains, but nature had delivered something special. We named the strain Fleur Jaune (Yellow Flower), honoring its botanical origin. Its brewing properties proved exceptional.
Once the initial lab trials were complete, samples were sent to WHC Lab in Dublin, Ireland, a company specializing in yeast identification, propagation, and commercialization for professional brewers. After analysis, WHC recognized the strain’s unique fermentative and sensory potential and offered to bring it to market, initially in liquid form.
At the same time, Fleur Jaune was put to the test in six collaborative brews with European craft breweries. These real-world trials confirmed the yeast’s adaptability to hop-forward and aromatic styles — particularly IPA, pale ale, and expressive top-fermented beers.
What truly sets Fleur Jaune apart is its remarkable ability to biotransform hop compounds. In practical terms, it enhances and amplifies fruity and floral characteristics in hop-forward beers. Brewers who have worked with the strain consistently describe its profile as striking, expressive, and difficult to replicate with conventional yeasts.
From a wild flower in the highlands of La Réunion to fermentation tanks across Europe, the journey of Fleur Jaune is a rare example of a tropical indigenous yeast discovered, selected, and tested locally — before finding its place on the international brewing stage.
To date, Fleur Jaune is available in liquid form across much of Europe and Canada. We hope it will be available in dry form worldwide in the near future.
