Why are oysters green?

115719 Views 11/12/2022 0 comments Posted By: Emmanuel Poulet-Harmel In: Blog of gourmets

 The Fine de Claire Verte Label Rouge oyster has a green color obtained thanks to the presence in the Claires de Marennes of the blue navicule, this micro-algae is filtered by the oyster which retains the color. 

 If there is one specificity of the oysters raised in the Marennes-Oléron basin, it is their green color.  that cannot be found anywhere else. The Seudre marshes, in which oysters are stored after sea farming, are home to a microscopic algae that colors the oyster with its pigment “marennine”. 

 The Marennes oyster was already Louis XIV's favorite dish. Although its green color seemed suspicious to his minister (Seigneley thought the Protestants wanted to poison the king), the Marennes oyster had a place of honor on the royal table. 

 The navicula live in a planktonic state on the coast. They periodically penetrate into the clear according to the tides. 

 These clay basins, which were once salt marshes, offer excellent conditions for the development of diatoms. 

 If the environmental conditions are favorable, the microalgae land on the clayey soil of the clear then multiply, turn blue, and release the marennine which will attach itself to the gills of the oyster. 

 It is therefore impossible to reproduce this phenomenon of greening elsewhere, since it is first of all the clay soil of the Claires which allows the development of this magic algae!