|Small-Scale Processing of Fish (ILO - WEP, 1982, 140 p.)|
|CHAPTER II. SALTING - DRYING - FERMENTING|
|I. FISH PREPARATION|
It is usual to split lean fish from the belly side, a method known as cod splitting, although all large round-bodied fish can be processed in a similar way.
Plate II.1. Cutting knives and sharpening tools
1. Oilstone (in protective box)
3. Or skinning
5. Block fillet knife
6. Kippering (herring splitting) knife
7. Gutting knife
8. Cod splitting knife
9. Large broad-
10. bladed knives
Plate II.2. Protective clothing and filleting table
Figure II.1. Fish filleting table
This method can only be practised if the fish has been gutted before splitting. In some fisheries, however, splitting from the back is the usual practice. This latter method of splitting is known as mackerel splitting. Whatever the method, all cuts should be made with a clean sweep of the knife as ragged cuts spoil the appearance of the fish and salt penetration and drying are likely to be uneven. Cod-style splitting of a large fish is illustrated in the sequence of Plates II.3 to II.10.
To gut the fish, prior to splitting, a single cut should be made from the vent to the throat. The guts should be pulled out in one piece and cropped into a barrel or other suitable container.
After splitting and if the flesh is thicker than about 2 cm, scoring cuts should be made along the length of the fish at intervals of 2-4 cm depending on the flesh thickness. These scores should not be so deep as to cut through the skin.
All black membranes should be removed from the inside of the fish. It is important that no pieces of gut remain. The fish should then be carefully washed.
Back or mackerel splitting is commonly used with smaller and fatty fish. The head is invariably left on. The method is illustrated in Plates II.11 to II.15 in the case of herring. After splitting, the guts, gills and hearts should be removed and, using a small brush, the dark coloured blood next to the backbone cleaned out. The fish should then be washed thoroughly.