Ikejime uses a brain spike to cause the immediate brain death of a fish. This might sound barbaric, but it’s the most humane way to kill a fish. To improve the fish’s taste and quality, a wire or stream of pressurized water is pushed through the spinal cord of the fish. This destroys the nerves, which prevents the micro-twitches in the muscle tissue, which reduces the degradation of the cells. Next is optional: clean the gut cavity or put the fish on ice.
We recommend using quality ikijime tools and proper protection, so you don’t hurt yourself during the process. Gloves are recommended to reduce the chances of puncture wounds from the spike or cutting yourself on the fish’s fins and gill plate.
What is Ikejime?
Ikejime or Ike Jime, is pronounced as “ay-kee jime or ee-ke jime” or shinkei jime, is a Japanese method of preparing the fish by paralyzing and draining them of blood to avoid rotting. This destroys the nerves, which prevents the micro-twitches in the muscle tissue, which reduces the degradation of the cells. The correct technique should preserve or enhance the flavor and texture of the fish when aged.
Ike Jime Tools
- Ikejime Spike – You’ll want a sharp and robust spike to euthanize the fish when puncturing the brain.
- Shinkei-Jime Wire – To sever the nerves from firing after the fish has been dispatched, you’ll run a metal wire down the spinal cord from either the head or tail.
- Sharp Knife or Pliers – This will cut the gills to bleed out the fish.
- Bucket – This is an excellent filling with water to soak the fish as it bleeds out.
- Salted Ice Water – Create an ice slurry with a 1:1 ratio of saltwater (fresh is less desirable) and ice.
How to Ike Jime Fish
Time needed: 3 minutes
Learning how to ike jime and shinkeijime a fish will produce the best-tasting fish. The first few times will be challenging, but you’ll soon get the hang of it!
- Spike the Fish Brain
The first step (brain spike) in the process takes a bit of practice, but after you try it a few times, you’ll get the hang of it.
You’ll want to locate the brain from the fish’s front or side for the brain spike. We look for the lateral line to see where the spinal cord and the eyes are. Depending on the fish, the brain will be slightly higher than the eyes.
Take your ike jime spike and push it through the skull. If you hit the brain, the fish will spasm, and the jaw will drop. - Bleed the Fish
The fish’s heart will still pump even after you spike the brain.
Now that the fish is dead, you’ll want to expel as much blood as possible, which houses harmful bacteria and will tarnish the flavor of the flesh.
The easiest way to bleed a fish is to cut the gills on both sides with a sharp knife or scissors. Then place the fish in ocean water (preferably water in a bucket, getting warm on deck for a bit). Give it ample time to bleed out.
Just don’t wait all day, allowing the fish to get warm, which will tarnish the meat. Shoot for 5-15 minutes before using the shinkei-jime wire in the next step. - Sever the Spinal Cord With a Shinkejime Wire
You want to prevent the fish from sending more stress signals to its body by destroying its nervous system. This is done by putting a sharp shinkei-jime wire into the spinal cord and running it from the brain to the tail or vice versa.
You’ll notice the wire is in the right spot when the fish starts twitching as if it came back to life. This is normal, and there’s no need to worry since the fish has already been dispatched.
The nerves are severed, sending the last signal through the fish, making it twitch.
It’s helpful to move the wire up and down a bit to ensure everything has been severed.
Just be careful not to damage the wire by pushing it too hard down the fish. It should go down with minimal force. - Cool the Fish Down Quickly
The days of leaving a fish on the deck in a burlap sack or a cooler with a tiny amount of ice are dead.
For quality fish, you need to get the temperature of the meat down as fast as possible. This means putting the fish in an ice slurry below 41 degrees F. Saltwater and ice is preferred over freshwater since the salt helps keep the water cooler and reduces further damaging the cells of the flesh.
Place the fish in the tank how they would swim in real life. For space, it’s helpful to put the fish from head to tail like a zipper.
Congrats, you’ve completed the ikejime process. You can gut, fillet, or store your fish for transport when you get to the deck.
Can You Use a Bat or Priest to Wack a Fish?
This is a viable option, but it has a few disadvantages. It could take a few wacks to knock out the fish, which could be hurtful to the fish, damage the meat, or even damage yourself or the boat.
Ikejime Tuna Tips
High-end restaurants worldwide buy fish from sellers who use this technique to ensure the highest quality of meat possible to serve their clients. A properly ikejime’d tuna increases its price per pound.
Tuna run hot, especially when fighting away from the boat. It’s critical to brain spike and start bleeding the fish immediately, preferably before it even hits the boat deck, so it doesn’t bruise the flesh.
Depending on the size of the tuna, you’ll need a more significant and robust ike jime spike and shimkejime wire. You’ll also need lots of ice and a big storage area to reduce the temperature as quickly as possible.
Ike Jime Method for Freshwater Fish
Using the ike jime method on freshwater fish isn’t discussed much since much of the focus has been on commercial fishermen. The times are changing, and you can start experimenting with the process for many fish, including trout, walleye, bass, crappie, bluegill, and more.
Ikejime Trout
When most people think of ike jime, they think of tuna or other fish species. However, you can do it with all types of trout, including rainbow trout, browns, chars, and whatever else is legal in your local waterways.
The process is similar, but the tools can be adjusted depending on the size of the fish. Since most trout are usually smaller, there’s a small freshwater ike jime kit that is convenient for backpacking around small streams and ponds.
If you’re catching monsters, the standard ike jime kits will work well too.
Ikejime Walleye
Walleyes are popular to catch in the midwest, and few folks know about ikejime. If you want to impress your friends and show off a new technique, give it a try!
Insider Advice
Any fish we catch is a fish that deserves our respect and care, especially in its final hour.
Ikejime preserves its taste and vastly improves its quality. If you spend the money to catch a fish, you might as well spend a bit more and learn a new technique that will pay dividends on your plate.
What we can do in the kitchen with seafood has significantly been overlooked compared to beef and other terrestrial meats. Let’s change that! The flavors unlocked with a bit of education will go a long way.
One other helpful tip: have a few different size ikejime kits at the ready. You never know what size fish you’ll need to process!
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