Oysters: What are they? And how to cook them?

From opening and frying to grilling them

Never eaten oysters? They take some getting used to, you either like them or you don’t. But what kind of critters are oysters anyway? Are they good for you? And how can you cook them? You can read the answers to these questions and more below.

Chapter 1

What are oysters?

The common oyster is a marine bivalve mollusk and is also known as the flat oyster. The shell consists of two valves, a flat top cover and a curved bottom cover.

On the outside, the shell is rough, gray and hard, and on the inside, the flesh can vary from creamy beige to gray in color.

An oyster has, among other things, a heart, a stomach, blood vessels, muscles, a mouth, kidneys, a mantle and gills. With its gills it sifts small algae particles from the water that it uses as food. With his muscles he opens and closes his two valves to eat or he uses them to protect himself.

There are two types of oysters in the Netherlands: the common and Japanese oysters. The common oysters grow to 5 to 15 cm in size and the Japanese oysters to 40 cm. Growth takes 5.5 years in warm waters and about 4 to 5 years in cooler waters.

Oysters grow on hard surfaces. When they lay eggs, many eggs are released at once. The Pacific oyster can lay 200 million eggs every ten minutes. After fertilization, an oyster larva attaches itself to the hard bottom or sometimes to another oyster. When many oysters grow on top of each other, this is called an oyster bed.

Some oysters are very valuable because they produce pearls. When a grain of sand, a piece of lime or dirt ends up in the shell, this can irritate the oyster considerably. The oyster then coats the unwanted particle with mother-of-pearl, the same substance that makes up the inside of the shell.

However, pearls are very rare. You have to open thousands of oysters before you come across one with a pearl.

Where do oysters come from?

Oysters are mainly found in the edge seas of the Atlantic Ocean from Norway to North Africa. They are also found in the Mediterranean Sea.

Due to overfishing, the natural populations of oysters in the North Sea have virtually disappeared. The Pacific oyster is abundantly present in the Dutch part of the Wadden Sea.

In the Netherlands, oysters are cultivated in the Oosterschelde and in the Grevelingen lake. The temperature, purity and salinity of the water, the soil and sheltered location make these areas the ideal places for oyster farming.

The oyster season for flat oysters in the Netherlands runs from September to April.

How do oysters taste?

Not only the shape and size, but also the taste of oysters depends on the region where they’re from. The aroma of oysters has been compared to melons, citrus fruits, cucumbers or nuts. They have both a salty and a sweet taste, with a slightly metallic aftertaste.

If you don’t like fish, you probably won’t like oysters. If you want to learn to eat fish, start with salmon and try oysters again later.

Are oysters healthy?

Oysters are low in calories and rich in vitamins and minerals. They contain a high content of zinc, magnesium, vitamins B12, B3 and D and omega-3 fatty acids. Zinc and magnesium play an important role in our metabolism. Zinc supports a healthy immune system, stimulates wound healing, strong bones, beautiful hair and a good memory.

Some people are hypersensitive to the proteins in oysters. Eating oysters can lead to skin irritation and nausea in these people, among other things.

Norovirus can occur in raw oysters. Symptoms include nausea, vomiting and diarrhea. You can kill the virus by heating the oysters to a temperature above 70°C.

It is said that oysters are an aphrodisiac and that the high zinc content in oysters stimulates sperm production in men. However, there is no scientific evidence for this. It is said that they contain rare amino acids that may stimulate the production of sex hormones.

Food & wine

The soft and salty taste of oysters, pairs well with a fresh and young white wine that does not have a dominating flavor; a wine that is dry and fresh, with a slightly fruity and mineral taste. The Ayala Brut Majeur Champagne or the Sauvignon Blanc are very suitable.

A dry white Bordeaux can also be paired well with oysters when they are used in a dish.

How do you open an oyster?

Oftentimes, an oyster has already been opened for you. If not, turn the oyster flat side up and insert the oyster knife where the two shells touch. Twist the knife to open the oyster, then cut the sphincter.

How do you eat an oyster?

It is best to eat raw oysters with some lemon juice and a pinch of black pepper. A good oyster is opaque and ivory colored. A fresh oyster has a salty and sea-like smell.

Loosen the oyster with a fork, put the shell to your mouth and let it slide inside. You are not supposed to swallow the oyster right away. Chew well (at least three times) to release all the flavors.

Oysters are still alive when you eat them. By chewing for a long time, you also prevent the oyster from ending up in your stomach alive. That can make you sick.

You can also eat oysters baked, grilled, fried or au gratin.

Chapter 2

How to cook oysters?

If you are going to cook oysters yourself, it is best to buy them from the fishmonger or fish shop where they handle them with care. Oysters need to be kept cold and alive until you eat them. Place oysters in ice to keep them as fresh as possible.

Always use a towel or oyster glove when opening the oysters and use a special oyster knife.

Do not overcook oysters or they will have an unpleasant rubbery texture. They only need to be cooked for a few minutes.

Oysters are already deliciously salty by themselves, so you don’t actually have to add more salt. Herbs like garlic and parsley pair well with oysters.

Chapter 3

Recipe: Grilled oysters in a parsley marinade

Chapter 4

All recipes

Looking for more inspiration? Then see below more recipes with oysters. Or check our fish recipes for even more inspiration.