If you have a fresh carp, or other large, fresh water fish, you will want to cook it as soon as possible. Sometimes, you can bring a hooked fish home alive, which is the freshest way to cook and eat fish.
If you can obtain a live carp and want to cook it whole, it is best if you let it live in a big tub of fresh water for several days to clean out the "mud vein" and have a better tasting fish. Dissolve one teaspoon of salt in the water every day to help the process. Do not feed the animal.
When it's time for dinner you can pin the carp against the side of the tub with one hand and stun it with a hammer in the other. The carp should then be gutted and scaled to prepare it for cooking. See this step by step guide for gutting bass by Ronnie Garrison.
The carp for this demonstration was given to me by my husband, who shot it with a bow and arrow. I am told that this is a fun pastime in the spring when the reservoir is full and the carp swim up in the grass. It's also full of mosquitoes and ripe for sunburn, so I declare it Man-Time and stay away.
Because of the bow and arrow routine, the carp had been dead about 45 minutes by the time we got started with the prep. It was covered in fish-slime, a polysaccharide gel that the fish exudes. The fish was too large for any pan I had and it had not swum in a tub, so I elected to make the New Year's Carp recipe with filets, removing the "mud vein" as I did so.