Crustaceans may be Australia’s favourite seafood. They’re easy to prepare, so tasty and versatile too. Most of these recipes could be made with any crustacean: prawns, bugs, rock lobsters, marrons or yabbies.
Shellfish is a general term for all aquatic creatures other than fin fish. It includes crustaceans and molluscs/mollusks which are further categorised into bivalves (such as clams), univalves (such as abalone) and cephalopods (such as squid).
Crustaceans, such as prawns (shrimp), are shellfish with a hard outer shell which they shed and replace as they grow. They have ten limbs (their Latin name is decapod, meaning ten-footed).
The most common crustaceans are prawns (shrimp), crabs, lobsters and rock lobsters, crayfish and bugs.
Prawns (also called shrimp) are the most commonly eaten crustacean, popular in cuisines across the globe. Crabs and lobsters, in many different sizes and shapes, are also popular crustaceans.
The most important thing when cooking crustaceans is not to overcook them. They can be briefly boiled or poached and served with a sauce, or split and grilled.
Raw crustaceans are called ‘green’, meaning ‘uncooked’ rather than as a reference to their colour. They vary in colour from species to species when raw, though all turn red when cooked.
Except for prawns, most crustaceans are often sold live, which gives rise to the problem of how to kill them humanely. Animal protection societies (such as the RSPCA in Australia) issue guidelines for the humane killing of live crustaceans.
My advice is to buy crustaceans already humanely killed by a fishmonger. If you must buy a live crustacean chill it in the freezer for 30-60 minutes (depending on size) until it becomes insensible (but not long enough to freeze it solid). Then place it into a large saucepan of rapidly boiling water, putting the lid on to return it to the boil as quickly as possible. It can then be boiled until cooked, or removed and prepared according to any recipe. It is neither humane nor good cooking practice to put an animal that hasn’t first been well chilled into boiling water as the animal will suffer and the stress will render the meat tough.
Despite being various colours in their raw state, all crustaceans turn red when cooked because their shells contain a carotenoid pigment called astaxanthin (like carotene, which gives carrots their bright orange colour). Astaxanthin’s colour isn’t obvious in live or raw shellfish because it’s bound with a protein that usually creates a blue-green colour. Astaxanthin is heat-stable but the protein isn’t, so when heat is applied the protein is destroyed, releasing the pigment and giving the typical red colour of cooked shellfish.
My advice is to buy crustaceans already humanely killed by a fishmonger. If you must buy a live crustacean chill it in the freezer for 30-60 minutes (depending on size) until it becomes insensible (but not long enough to freeze it solid). Then place it into a large saucepan of rapidly boiling water, putting the lid on to return it to the boil as quickly as possible. It can then be boiled until cooked, or removed and prepared according to any recipe. It is neither humane nor good cooking practice to put an animal that hasn’t first been well chilled into boiling water as the animal will suffer and the stress will render the meat tough.
