Do you prefer Ostrea Edulis or Crassostrea Gigas oysters?
Ostrea Edulis: the forgotten oyster
Ostrea Edulis, or European flat oysters, were originally the most common species in our region. Starting in the Quaternary Period, Ostrea Edulis oysters spread along the European fringes of the Atlantic, the coasts of Northern Europe, the Adriatic Sea and the Black Sea. Endemic to the European coastline, Ostrea Edulis was the only oyster species present in France until the end of the 19th century. However, it fell victim to epizootic diseases during the 20th century. Today, production of this species is limited, and flat oysters are rarer than their cupped cousins.
Next came Crassostrea Angulata, or “Portuguese” oysters, which were brought to France at the end of the 19th century by a merchant ship. Caught in a storm, this ship sought refuge in the Gironde estuary, where its cargo of oysters began to rot and stink, eventually being thrown overboard into the mouth of the river. Not all the oysters were dead, however, and this species adapted naturally to its new territory, becoming the main oyster species cultivated in France during the 20th century.
When these oysters were eventually struck by another epizootic disease that destroyed all oyster cultivation on the Atlantic coast in the 1970s, they were replaced by Crassostrea Gigas, or “Pacific Oysters”, imported from Canada and Japan, which today make up the bulk of oyster production in Europe.
You can distinguish Ostrea Edulis specimens from cupped oysters by their appearance. Their shell is more rounded and less ridged. Their flesh is a blond colour with traces of grey or brown. Their shells can come in spectacular shades of yellow, grey, or even purple.
Their body plan is slightly different from that of cupped oysters, which is perhaps what gives them a firmer, more compact texture. Some say they are almost as firm as clams are.
A distinct taste
The other major difference between flat and cupped oysters is the taste. Flat oysters have a bolder taste, with more ocean flavour and bitterness that lingers on the palate. This bitterness is characteristic of Ostrea Edulis oysters.
Flat oyster reproduction is also different to that of cupped oysters, with spawning occurring several months before Crassostrea Gigas, starting in April. It should be noted that, unlike cupped oysters, when flat oysters are “fat”, they do not lose flavour.
A flat oyster is something you earn
Flat oysters take their time, growing more slowly than cupped oysters (taking up to an extra year before they’re ready for harvest), which makes them rarer and more expensive.
In the French system, there are 5 categories of flat oyster:
000 is the largest. These oysters weight between 100-200 g.
00: 90-100 g
0: 80 g
1: 70 g
2: 60 g
3: 50 g
The Les Huîtres de St-Clément Oyster Bar sometimes serves flat oysters depending on availability. These oysters are 100% produced in the Ars-en-Ré salt marsh by Pascal Simaillaud, a claire salt pond aquaculture expert. Their taste is unmatched, lingering on the palate. Their flesh is crisp and firm, with pronounced ocean flavour and a slight bitterness at the end.