Hold the fish by the tail and insert the blade into the anus of the fish. Pull the blade through the belly of the fish, and upwards right through the position where the gill rakers meet (this junction of bony tissues is quite a tough joint). Place the fish on a board and cut through the back of the fish down through the backbone, without cutting the head off and not cutting right through.
Release the knife and holding the fish in one hand and the head in the other tear the head away from the body, which should remove the guts with it.
Using the point of the knife remove the blood in the kidney. This is in small bony cavities in the backbone near the tail and is hard to get at, but do try to remove as much of the blood here as possible.
Remove from the cold running water and allow the water to drain away from the fish. Some people prefer to cook the fish with the head and tail intact, but if you are putting the fish in the freezer, removing them will save space.
The carcass of the fish can be slid into a freezer bag labeled with the weight and date - or it can be cooked immediately (generally preferred to get the best flavour).
REMOVING THE BACKBONE
Lay the trout out as flat as possible and roll a bottle down the backbone. Turn the trout over and repeat. Cut through the backbone at the tail and head of the fish. Carefully remove the backbone.
