Cooking
Freezing and Cold Storage

Cooking

All lobsters should be kept alive until processing begins.

If lobsters are to be quick frozen, then it is better to cook them first. They give a product that undergoes less change in cold storage than the raw lobster.

Live lobsters should be plunged into boiling salt water.

Note: The Universities Federation for Animal Welfare recommend that live lobsters should be killed painlessly before cooking, either by immersion for two hours in cold fresh water, or by splitting them in half down the centre line using a large French cook's knife.

The water should contain about the same amount of salt as sea water, that is about two to three per cent salt.

In most commercial operations the lobsters are lowered into the water in some form of open mesh wire basket. The addition of a large quantity of lobsters to the water lowers its temperature below boiling point and cooking time should be measured from the time that the water temperature returns to boiling point.

A thermometer should again be used to check this, as judgment by eye is unreliable, particularly if live steam is used to heat the water.

The cooking time should be from fifteen to twenty five minutes depending on the size and thickness of the lobsters, and on the time that the water takes to reach boiling point again, which will in turn depend a great deal on the total weight of lobsters in the load. If too great a weight is put in at a time, the water may be cooled so much that the time taken to return to boiling point will be so long that the total cooking time will be excessive, resulting in some toughening of the meat. Care should be taken therefore not to overload the boiler.

A clock should be used to note boiling times accurately, once suitable times have been established by experiment for each size of lobster.

A load of lobsters of large size will take longer to cook properly than the same weight of small ones, since the heat will take longer to penetrate to the centres of the thicker fish.

Special care should be taken when processing ripe female lobsters. If these are inadequately cooked in water that is below boiling point, there is the likelihood that the ovary of the lobster will remain black. At or near to boiling point, the ovary will change in a few minutes to the red colour of the 'coral' familiar to the trade, but at about 70°C it may take more than half an hour to change, and at temperatures lower than that may not change colour at all.

Weight loss during cooking may be anything from 5 to 25 per cent of the live weight, with an average loss of about 14 per cent. The amount of weight lost does not necessarily bear any relation to size.

When cooking is complete, the lobsters should be left to cool and drain before shelling or wrapping. Cold running water may be used to accelerate the cooling if required. At all events, the cooked lobster should be spread out to cool, and not allowed to remain in a full basket, since cooling is then very slow, and quality may in consequence suffer.

Careful attention must be paid to hygiene throughout the process, all equipment being kept scrupulously clean, if the lobster meat is not to become a potential source of food poisoning. Your local health inspector will always be pleased to advise you on how to handle your product hygienically.

Freezing and Cold Storage

If lobsters are quick frozen raw, the flesh upon subsequent cooking is often soft and shrunken, and very difficult to remove from the shell without breakage. Flavour is usually poorer than for precooked lobsters.

Cooked lobsters may be frozen whole, wrapped individually in polythene. Large ones, usually those heavier than the popular range of from 1 1/2 to 4 kilos weight, may be opened and the loose meat packed into polythene bags or waxed cartons for freezing in weighed lots.

Air blast freezing is probably the most suitable method for irregularly shaped whole lobsters. A large lobster in a refrigerated air stream at minus 34°C is unlikely to take longer than two hours to freeze.

In cold storage at minus 30°C, quick frozen lobsters will keep in first class condition for at least six months.

Store temperatures above minus 18°C cannot be recommended, and the limit of storage at about minus 20°C would seem to be about three months.

The whole lobster appears to keep better than packaged loose meat, the storage life in good condition for the latter being limited to about three months.

Shelf life in good condition at chill temperatures 0° to 2°C of thawed, cooked lobsters after correct low temperature storage is about four to five days.

Loss in weight during freezing and storage may amount to about one or two per cent of the live weight.