Fish Oil Fish oil, a common lure ingredient and can be made yourself. To make fish oil, use medium sized fresh carp. Gut the fish and remove entrails but leave the head attached. Chop the fish into inch size cubes and place the pieces into a gallon jar. Using a flat lid for the jar, screw the lid on and back off about 1/2 turn. Over the lid and top of the jar place about three layers of broad cloth fabric. (This is to keep out flies and maggots so loosely woven fabric will not work). Hold the layers of cloth in place with a strong rubber band. Over this place a plastic bag and hold in place with a rubber band. Wrap a wire around the neck of the jar and hang up in a isolated place away from residences and where people aren't likely to bother it. Also make sure to hang it well off the ground where animals can't get to it. Locate this jar in a place where the sun will shine on it throughout the days in the summer. Try to prepare this fish oil in April before the fly season and hot weather gets under way. Leave the jars hang in the sun until mid-September. Strain the liquid into separate jars and store in a cool dark place. The clear yellow oil that rises to the top can be skimmed off as it is the best quality, however, all the liquid in the jar can be used.