Q: I catch thousands of pounds of scrap fish each year. I would like to know how to process fish to get the oil from them. I would also like to know how I can preserve scrap fish and package it to sell for trap bait. — S.B., Tennessee
Dave Morelli Responds:
I have put up fish oil in the past and have found it to work the best when the fish is an oily fish to start with. All fish have some oil in them. The more they have at the start, the more that will render out. I don’t know what kind of fish you are starting with so you might have to experiment with some to find out what produces the most oil.
My first bout with collecting sun-rendered fish oil was with the belly fat from some huge Mackinaw trout that I caught on a summer fishing trip. This part of the fish was not edible and I cut it away to render the oil out of it. I caught these fish in a different state than I lived in at the time and it would have been illegal to use the oil in the state I caught it in.
Trappers were not allowed to use any part of a game fish as bait. So, make sure the laws of your state allow the fish that you are using for bait. I assume it is legal as you refer to them as scrap fish. I have found carp render out pretty good.
Eviscerate the fish and cut the flesh into chunks that can be stuffed into a clean one-gallon glass jar. A bigger jar can be used if you have one. I only use glass and in this operation it should be clear. The late summer/fall is the best time to do this as there is plenty of sun, but the daytime temperatures are starting to cool down. It can be done most anytime of the year that is warm, I like it when the temps aren’t scorching so the flesh ages more than rots.
I put the lid on the jar with some T-shirt material in between the lid and the mouth of the jar to let the gasses out and keep the flies from getting in. One fly will produce many eggs and a bunch of maggots is not what you want to find in the jar. The flies won’t interfere much with the oil production, but you really don’t want them in the remains if you want to make bait with it.
As the days in the sun go on, there will be oil collecting at the bottom of the jar and when it increases to an amount that can be poured off, do so into a clean jar. I like to cut the fish into chunks instead of grinding it for this process because it is easier to pour off through the chunks than through a blob of ground fish. Some sort of screening material will keep chunks of fish from contaminating the oil.
The material that is left in the jar when the oil stops forming will be fragrant to say the least, and downright rank to be most correct. Used as it is it will most likely cause coyotes to roll in it. If it is preserved with sodium benzoate and aged in a cool dark place, it will sweeten some and make a great additive to other baits or work on it’s own merit. I like to use it as a stinky additive to my spring bear bait as it would call them in from a great distance and get them working the station.
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