There are several telltale signs that will help you to identify a fresh fish:
When buying fish, pay attention to the smell above all. A fresh fish has a pleasant, neutral smell reminiscent of the sea. It's important that it doesn't smell at all unpleasant. An unpleasant smell is a sure sign of an old or incorrectly stored fish.
The fish meat should compact, firm and elastic to the touch. To determine whether the meat is firm and elastic, press down on the fish firmly with your finger. If the fish is fresh, the meat will spring back into its original position and your finger won't leave a hollow.
The eyes should be moist, taut and clear, with translucent, full and convex pupil. The eyes should never be sunken or opaque.
The gills should be a bright, light red colour. Individual gill filaments should be clearly visible; they should not be stuck together, slimy, light yellow or, worst of all, brown in colour.
The skin should be soft and moist, with a natural colour and silky sheen. The thin layer of mucus on the skin should be undamaged and translucent. Old fish are often covered in a grey, yellow, greenish or brownish layer of mucus.
The fins should lie firmly along the body. They should never be stuck together or dried out. Damaged fins are a sign of incorrect fishing or long transport. Pay attention to the fins and make sure they're well preserved and shiny.
When you open the fish, the interior walls of the stomach cavity should be a light rainbow colour (in some herbivorous fish, the stomach walls are entirely covered with a black membrane, which can be removed with a finger or knife) and firm to the touch. Bones should stick to the flesh, there should be a lot of light red blood, the liver should be an even shade of light brown and there should be no bile leaks. An unpleasant smell, bones coming away from the flesh or dark and dried blood are sure signs of an old fish.
When making raw fish dishes, it is particularly important that the fish is fresh. Since some species of fish are often plagued by parasites than can be harmful to human health, the whole fish or fish fillet should be frozen quickly before it is used in raw fish dishes. Leave the fish in the freezer for at least 28 hours to make sure that any parasites are killed. Then you can defrost the fish and use it safely.
Use a sharp knife or tweezers to remove the bones. Run your fingers along the entire length of the fillet to make sure that you've removed every last bone.
How to make sea bass carpaccio:
Do not remove the skin from the fillet. Place the fillet skin down on the cutting board and slice it very thinly in a diagonal direction from head to tail. You can also use a prosciutto knife to cut thin slices along the entire length of the fillet. Place the slices on a plate and season them just before serving with flower of salt, mild olive oil and freshly ground pepper to taste.
If preferred, the fish slices can be briefly marinated in citrus juice (orange, lemon, lime and/or grapefruit). To reduce the intensity of the fruity flavour, you can drizzle the slices with olive oil first. If you prefer the fruity flavour, marinate the fish slices first, then add some olive oil and flower of salt. We recommend that you try the flower of salt and olive oil method first and turn your hand to marinades later.
How to make sea bass sashimi:
As in Japanese cuisine, remove the skin, place the fillet on a cutting board with the outside part facing down and cut it in a diagonal direction from tail to head into slightly thicker slices (0.5 cm). Since you're cutting across the muscle fibres, the fish slices will be very tender and soft. Serve seasoned with flower of salt and olive oil, with wasabi and soy sauce, on rice balls, etc.
How to make sea bass tartare:
Remove the skin and place the fillet on a cutting board with the outside part facing down. Slice lengthways into thin ribbons, then slice across from tail to head so you're left with more or less even cubes. Season with flower of salt and olive oil. If preferred, add some soy sauce, thinly sliced organic lemon zest and strings of courgette peel. Prepare the latter by peeling the courgette and finely chopping the peel.
Fish stock is made from fish heads, bones and skin left over after filleting. If available, you can enrich the stock with other types of fish (grey mullet, sardine, monkfish, etc.), a few mussels, pieces of a whole prawn or leftover prawn shells.
Fill a pot with about 1 l of cold water. Place the fish bones, heads and skin in the pot and add about 200 g of cleaned, washed soup vegetables, a bay leaf, 2 tablespoons of olive oil and some salt. Gently simmer for about 1 hour. Mush or blend the stock thoroughly and strain. The fish stock can be used for cooking immediately or divided into smaller containers and frozen for later use.
If you're planning to make a dish that requires steamed mussel meat, the mussels can be prepared in advance and kept in the refrigerator or freezer until needed.
Take a pot (preferably wide and not too tall) and fill it with just enough water to cover the bottom. Bring to the boil and fill the pot halfway up with mussels rinsed under cold running water. Cover with a lid and steam the mussels for 5 to 10 minutes or until all the shells have opened. While the mussels are cooking, stir or shake the pot occasionally. Leave to cool slightly and separate the meat from the shells. This is easily down using a spoon, an empty mussel shell or your fingers – squeeze your thumbs between the shells to reach the meat. Don't forget to remove any byssal threads that didn't fall off during cooking. Be sure to discard any mussels that didn't open during cooking.
If you're planning to freeze the mussel meat, divide it into containers of a suitable size (e.g. glass jars), add the water they released while cooking, close the containers and freeze them.