Oysters

They are considered one of the finest delicacies. Their unique flavour is a combination of delicate brininess and light mineral tones. Whether served at a festive dinner or enjoyed simply for the pleasure of it, oysters have always remained a symbol of elegance and luxury.

Where Do They Hide?

Oysters are found in coastal areas around the world, where they live attached to rocks, coral reefs, or special farms. Some of the most well-known oyster farming regions include:

• France's Coastline: Normandy and Brittany are oyster havens with a rich history of cultivation.

• Chesapeake Bay, USA: Home to some of the largest oysters in the world.

• Japan: Known for their sweet and delicate Kumamoto oysters.

• Australia: Sydney rock oysters have a firmer texture and saltier flavour.

  
  

Oysters grow slowly, which is what makes them so valuable. It takes several years for them to reach a size suitable for consumption, and during this time, they acquire their distinct flavour, influenced by the environment in which they live.

How Do They Move?

Although it may not seem like it, oysters are not passively attached to the seabed throughout their entire lives. As larvae, they are active swimmers—moving using tiny cilia that help them search for the perfect spot to attach. Once settled, they stay in the same place for the rest of their lives.

Life and Reproduction

Oysters are hermaphrodites, meaning they can be both male and female at different stages of their life. They feed by filtering algae and other small food particles from the water they almost constantly draw in through their gills.

Reproduction happens when the water warms, with oysters releasing their gametes into the water (a process known as broadcast spawning). Fertilized eggs develop into larvae, which eventually transform into young oysters.

This process is one of the reasons oysters are so sensitive to water cleanliness—any form of pollution can threaten their population.

Water Filtration and Ecological Significance

One oyster can filter up to 190 litres of water per day. Sediment and excessive nitrogen cause problems in the waters.

While nitrogen is an important nutrient for plants and animals, its excess—often from fertilizer runoff and septic systems—promotes the growth of algae, which overwhelms water bodies and reduces oxygen levels.

The Shells

Oyster shells are typically oval or pear-shaped, but their appearance varies greatly depending on the surface they attach to. The exterior is usually a pale grey, while the interior is porcelain white. Oysters have very strong adductor muscles, which allow them to tightly close their shells when threatened.

Oysters and Pearls

When a foreign object, such as a grain of sand, enters an oyster, it starts to protect it by enveloping it in layers of nacre, forming a pearl.

Interestingly, not all oysters create pearls. Those farmed for gastronomy usually do not produce pearls. On the other hand, pearl oysters, a relative of the oyster, are specialized in pearl production. The rarest pearls come from Japan and Tahiti and are prized for their size and intense luster.

Types of Oysters

There are many types of oysters, each varying in size, shape, and flavour. Some of the most popular varieties include:

• Pacific oysters (Crassostrea gigas): The most widespread species globally, known for their buttery and slightly sweet flavour.

• European flat oysters (Ostrea edulis): Popular in Europe, especially France, with a full and subtly nutty flavour.

• Sydney rock oysters: An Australian delicacy with a richer, saltier taste.

• Kumamoto oysters: From Japan, these small, sweet oysters are perfect for beginners.

• Rock oysters: Valued for their firmer texture and mineral flavour.

How Are Oysters Harvested and Imported?

Oysters are harvested in two main ways:

• Natural collection: Divers or fishermen manually collect oysters from the seabed. This process is labor-intensive but gentle on nature.

• Farm cultivation: Oysters are grown on special nets or structures submerged in water. This method is environmentally friendly and allows for quality control.

After harvesting, oysters are carefully sorted and placed in clean water tanks to remove sand and impurities. From there, they are shipped worldwide—either chilled or on ice—to maintain freshness.

Storing and Preparing Oysters

Oysters should be stored in a damp environment at temperatures between 1–4°C. It’s ideal to place them on ice and cover them with a damp cloth.

Opening the Shell: Hold the oyster firmly in your hand. Insert the knife into the joint at the back of the oyster and gently pry it open.

Cleaning: Carefully remove the top shell and gently cut the muscle that connects the meat to the bottom shell. Be careful not to leave any shell fragments inside.

Oysters and Health

Oysters are not only a delicious treat but also a healthy addition to your diet. They are packed with zinc, which supports immunity, and omega-3 fatty acids, which benefit heart health. Oysters are also rich in protein, vitamin B12, and minerals like selenium and iron.