This note gives advice on how to choose good quality fish and shellfish and store them at home. Information is given on wet, frozen and smoked fish products. The shopper is advised to make the fullest use of the expertise of the fish seller, and is urged to try less well known species when they are in good supply.
The shop
Fish is a perishable commodity, and the discriminating shopper gets the first pointers about quality from the standard of the shop. Whilst immaculate surroundings are no guarantee, fish that are well presented on ice in a cool, clean display unit are more likely to be of good quality than fish in an untidy heap on a warm and messy open counter.
Most fishmongers and managers of fish departments in larger shops are knowledgeable about their products, and shoppers should not hesitate to seek their advice, not only about quality or choice of cut, but also about the wide choice of species available. Although many customers are familiar with only a handful of names of fish, dozens of varieties are regularly marketed in the UK, and for many dishes there is often a cheaper but equally suitable alternative; shoppers can often be pleasantly surprised if they are more adventurous in their buying. Shellfish offer a wide range of species, from crustaceans such as crab, lobster, scampi and shrimp to molluscs such as oysters, mussels, cockles and squid.
Traditional eating habits die hard, but many shoppers have found that when the family is presented with a new species of fish cooked in an appetising way there is a gratifying response to something that is different and at the same time often more economical.
Shoppers should not forget the frozen food cabinet when buying fish; an ever increasing choice of fish and shellfish and of prepared fish dishes in convenience form is available from the freezer, and quality can be every bit as good as that of fresh unfrozen fish.
Wet fish
The term wet fish means unfrozen fish, normally kept chilled or at close to ice temperature, and sometimes described as 'fresh' fish. The term fresh is better used to describe the eating quality of all forms of fish; whilst wet fish usually is, and certainly ought to be, fresh, by the same token some wet fish on offer can occasionally be stale.
The freshness of wet whole fish can readily be judged by appearance on the display counter. First the eyes should be clear, bright and bulging or flat, not sunken and cloudy. The colour of the gills should be bright red or pink, and any slime present on them should be clear and colourless. The odour of the gills should be sharp and seaweedy. The colour of the skin should be bright, and any slime on it should be clear; yellow slime indicates staleness.
If the fishmonger then fillets the fish in the shop, the flesh of most species of lean or white fish should be white, and almost translucent; there should be no signs of reddening along the backbone, nor discoloration of the flesh. When pressed with the fingertips the flesh should feel firm and elastic; flesh that is limp and soft, and remains indented after pressing, is stale.
Some species have specific telltale signs of staleness; skate and dogfish for example quickly begin to smell strongly of ammonia when they become stale, and small whole fatty fish like herring and sprats, which are normally sold ungutted, often show signs of bursting around the belly when they are kept too long.
Fish displayed as fillets or steaks are more difficult to assess on appearance, because there are fewer characteristics to look for. Again the flesh should be translucent, with no yellow, brown or red discoloration, and should have a clean, sharp smell; any skin on the product should feel smooth, not gritty, and any slime on the skin should be clear, not discoloured. The flesh should feel firm and springy to the touch. There should be no reddening around the bone in a steak.
Prepacked wet fish should display a sell-by or best-before date; the shopper should check this, and not buy packs after their expiry date.
Shellfish quality is more difficult to describe in general terms because of the wide variety of species on offer. Some shellfish, for example lobsters, crabs, oysters and mussels, are often sold live, and furthermore some of these, for example oysters, are brought live to table and eaten raw. It is obvious if a crab or lobster is alive, but less so for molluscs; bivalves like oysters and mussels must have the two halves of the shell tightly closed or, if open, should close immediately when disturbed. Molluscs to be eaten raw must be from clean waters or have been treated by an approved cleansing procedure; the safest way to ensure this has been done is to buy only from a reputable supplier.
Shellfish sold wet but not live should have a wholesome, sharp seaweedy odour. Cooked shellfish, for example crab, shrimp, cockles and mussels, should have a sharp seaweedy or boiled milky odour, and no hint of ammonia. The shell of crustaceans should be free of black discoloration; exceptionally crabs may on occasions have a slight black spotting that does not affect the quality of the meat.
Crustacean meat, apart from the brown meat of crab, does not vary much in quality or yield from season to season, although the meat may be a little soft and watery after the animal has moulted. The brown meat of crab, however, and the meat of molluscs vary considerably in quality according to season, since the edible parts are often roe and liver, which build up periodically. Again, the advice of the fishmonger about seasonality can be a valuable guide to when to buy.
Frozen fish
Because frozen fish and shellfish are usually offered for sale in packs, there is little opportunity for the buyer to inspect for quality, and greater reliance has to be placed on other indicators. First, any sell-by or best-before date on the pack should be checked; packs beyond their expiry date should not be bought. Secondly, the shopper should not buy packs in the cabinet that are stored above the marked load line; the practice of storing above the line means not only are those packs subjected to too high a storage temperature and therefore liable to deteriorate faster but also that shop supervision of frozen products generally is lax. Similarly a glance at the cabinet thermometer will indicate whether good practice is being followed; frozen fish products in a display cabinet should be held at - 18°C or lower, and storage at a higher temperature can only result in rapid deterioration in quality.
Packs of frozen fish should be rejected if they feel in the slightest degree soft, suggesting partial thawing, or if any visible part of the fish has white matt patches indicative of dehydration, or freezer burn as it is called. Packs should be tightly closed, undamaged, and when opened should not contain large quantities of frost or ice crystals.
Smoked fish
The shopper inspecting unfrozen smoked fish should look for the following signs. The cut surface of the fish should be smooth and glossy, free from smuts, dirt or fragments of blood or guts, and the flesh should have few gaps or holes in it. A dull matt surface and badly gaping flesh are often signs of poor quality fish having been used for smoking, and debris on the surface indicates lack of care during processing. Patches of crystallized salt on the surface suggest the fish have been too heavily brined and that they are likely to prove too salty when eaten. Colour is not a particularly useful guide to quality of smoked fish; permitted dyes are used on many smoked fish products to meet the preferences of particular markets, and there can be considerable variation in the colour of both dyed and undyed smoked fish from one part of the country to another. Whatever the colour, it should be uniform and free from blemishes.
The flesh of smoked fish should feel firm and springy to the touch, and the surface should not be sticky; smoked fish with soft flabby flesh and a sticky surface are stale. The odour should be fragrantly smoky; smoked fatty products such as kippers often develop rancid, linseed-oil-like odours when stale.
The display of smoked fish in a shop should be separate from the wet fish. Where ice is being used to keep the display cool, smoked fish should be in trays on ice; smoked fish laid directly in ice becomes soggy and loses its smoky flavour.
Wet fish
Wet fish of good initial quality can be kept loosely wrapped in polyethylene film in a domestic refrigerator for 1-2 days. If it has to be kept unrefrigerated, wet fish should be wrapped in a clean damp cloth and put in the coolest part of the larder, preferably in a draught, and used within 24 hours. Wet fish should always be kept apart from other foodstuffs to avoid tainting.
Crabs and lobsters bought alive should be cooked on the day of purchase. Molluscs to be eaten raw should be covered with a clean damp cloth in a refrigerator; oysters should be stored with the cupped half of the shell downwards to retain the liquor. They can be kept for 2-3 days.
All other shellfish bought raw should be stored in a refrigerator in the same manner as wet fish. Cooked shellfish, especially extracted meats, should be handled very carefully and preferably eaten the same day; otherwise food poisoning may result.
Frozen fish
Frozen fish can be kept in the icemaking compartment of a refrigerator for 3-4 days. If a freezer compartment of a refrigerator has a star marking, frozen fish can be kept for 1 week in a one-star *, 1 month in a two-star ** and 3 months in a three- star *** compartment. Most domestic freezers have a three-star rating and will keep properly wrapped frozen fish products in good condition for 3 months.
The icemaking compartment of a refrigerator should never be used in an attempt to freeze unfrozen fish; freezing will be far too slow and the fish will spoil. Fish can be frozen in small batches in a home freezer provided the maker's instructions are followed, but thawed frozen fish should not be frozen again or there will be considerable loss of quality.
Many frozen fish products do not require to be thawed before cooking them; instructions on the pack should be followed carefully to achieve a satisfactory result. Cooked frozen fish should be sweet, meaty and succulent, and free from taint. Products that taste sour, bitter or rancid should be rejected, and the remainder of the fish or package returned to the supplier with a complaint.
__________________
If you have any enquiries, write, 'phone, or call at any of the addresses below:
|
|
The Director, |
The Officer in Charge, |
|
|
Torry Research Station, |
Humber Laboratory, |
|
|
PO Box 31, |
Wassand Street, |
|
|
135 Abbey Road, |
Hull, |
|
|
Aberdeen AB9 8DG |
HU3 4AR |
|
|
Tel. 0224 877071 |
Tel. 0482 27879 |
61 Gaping of fillets, by R. M. LOVE.Earlier notes in the series, most of which are still available, are summarized in:
62 The freezing time of fish, by F. J. NICHOLSON.
63 Fishing ports in the UK, by J. J. WATERMAN.
64 Fish silage, by I. TATTERSON and M. L. WINDSOR.
65 Fishworking machinery, by S. MAIR.
66 Handling and processing mackerel, by J. N. KEAY.
67 The haddock, by J. J. WATERMAN.
68 Icemaking plant, by J. GRAHAM.
69 Cook-freeze fish products, by J. N. KEAY.
70 Advice for the fish industry; who does what, by J. J. WATERMAN.
71 Processing cod; the influence of season and fishing ground, by R. M. LOVE.
72 Reducing odour in fish meal production.
73 Stowage of fish in chilled sea water, by J. H. KELMAN.
74 Handling and processing rainbow trout, by A. MILLS.
75 Freezing small pelagic fish, by I. MCDONALD.
76 Dark colour in white fish flesh, by R. M. LOVE.
77 Squid, by G. D. STROUD.
78 Health hazards of handling industrial fish, by A. WARD.
79 Minced fish, by J. N. KEAY.
80 Round worms in fish, by R. WOOTTEN and D. C. CANN.
81 Handling and processing blue whiting.
82 Hot smoking of fish, by A. MCK. BANNERMAN.
83 Fish smoking: a dictionary, by J. J. WATERMAN.
84 Handling and processing oysters, by G. D. STROUD.
85 Chilled and frozen fish: a dictionary, by J. J. WATERMAN.
60 Key to Advisory Notes 1-59, by J. J. WATERMAN.
Crown Copyright Reserved
Printed in Scotland by Her Majesty's Stationery Office at
HMSO Press, Edinburgh
Dd 8210470 10,000 4/81 (17789)
