Ikejime: a humane way to kill fish that makes them tastier

By Katherine Waters

“I’ll have to have a pair of glasses to do this shortly,” says Daniel Wood as he threads a wire through the spinal cord of a dead sea bass. As the wind whistles eerily through the fishing lines, the dead fish seems to spring to life. Its fins flare, its mouth gapes and its body spasms as the metal filament proceeds along the length of its spine, destroying nerves. When the filament reaches its cranium, the fish relaxes. Wood removes the wire, checks the incisions at the tail and gills and submerges the bass in a bucket to bleed out before transferring it to a cooler filled with a slurry of water and ice.

It’s a calm day in Cornwall and we’re drifting in Wood’s boat, Orca, just off the Lizard, the southernmost tip of mainland Britain. Wood, dressed in a sun hat and a thick camouflage-print jumper under heavy-duty yellow waders, is one of a handful of British fishermen practising ikejime, a Japanese way to kill fish which – its advocates claim – is both more humane than other methods and likely to result in tastier fish. Wood was taught ikejime by Yoshinori Ishii, the head chef at Umu, a restaurant in London with two Michelin stars. When Yoshinori arrived in Britain from New York nine years ago, he was appalled by the quality of produce available. “It was like I lost a hand,” he recalls. “Ingredients are most important in Japanese cuisine.”

Yoshinori is a trim, energetic man, whose little free time is filled with artistic pursuits like flower arranging, calligraphy and kintsugi (the Japanese art of repairing broken pots). As he sips espresso in his wood-panelled restaurant, he laments the freshness of fish in Britain compared to Japan. The fish you eat at a restaurant in Kyoto, where Yoshinori trained and worked, might have been caught as recently as six hours beforehand – even live fish can be delivered to order. Over here it’s a different story. “When fish comes to London, it’s already a question mark for me,” he says. Unless a boat comes in the same day as it goes out, a catch might have already lingered for a day in the hold. Even if the fish is treated well – kept cool, handled carefully – its freshness rapidly diminishes, along with its taste.

Yoshinori was determined to bring ikejime to Britain, and, five years after getting in touch with Kernowsashimi, the Cornish wholesaler that employs Wood, he finally convinced a handful of their fishermen to practise the fiddly and time-consuming technique. Ikejime, which translates as “closing the fish”, was refined about 200 years ago during Japan’s Edo period. The development of innovative ways of killing and preparing fish had been encouraged by Japan’s 1,200-year-long ban on eating meat, which wasn’t lifted until 1872. Ikejime prolongs the length of time for which the flesh remains fresh beyond other methods of slaughter, meaning chefs can take advantage of a greater range of textures and control the development of umami as the fish ages. What’s better for the chef is also better for the fish: ikejime involves ending the fish’s life in the least stressful way, as soon as it comes out of the water.

Japanese chefs will tell you that there are three variations on ikejime. You can simply submerge them in ice water (a method known as no-jime). You can stun the fish, immediately spike them in the brain and leave them to bleed out in water through an incision in their gills (standard ikejime). Or, like Wood, you can feed a wire along the fish’s spinal cord in between spiking and bleeding (shinkei-jime). All three methods delay the process of putrefaction. Shinkei-jime is the most effective because it destroys nerves that would otherwise encourage the build-up of lactic acid.

Sashimi benefits most from ikejime. Whereas sushi is best once the fish has passed through rigor mortis – when the flesh has become tender and the concentrations of umami acids have risen – the best time to eat sashimi, according to Yoshinori, is before rigor mortis. No-jime can delay rigor mortis for an hour, standard ikejime for about eight hours and shinkei-jime for up to 24 hours. Yoshinori serves me a bowl of turnip purée, garnished with caviar and draped with slices of raw Arctic char, a cold-water fish from the salmon family. The texture is extraordinary: silky but crunchy, like microscopic bubble-wrap. To follow is a plate of turbot usuzukuri, sliced to translucence. It too snaps between the teeth and while there’s depth to the flavour because the umami has had time to develop, it still tastes freshly caught.

Simon Bradley also works for Kernowsashimi and learned ikejime from Yoshinori. Fish prints line the walls of his home in the picturesque fishing village of Cadgwith and a chunky silver ring in the shape of a fish hugs his little finger. Bradley was a policeman in London until a car crash damaged his spine so badly he had to retire on medical grounds. His wife encouraged him to move to Cornwall, where he embarked on his new career. He skippers a boat called Shrimpy and his specialty is cephalopods, “octos, squiddlies and cuttles”, which he describes as “super smart”. He believes the speediness of ikejime minimises any suffering the fish might feel: “As soon as you go in and through [with the spike], it’s no longer a living soul. You know that sense when something’s gone?”

Most fish caught on British boats die long, drawn-out deaths, suffocating in the open air or expiring as they are eviscerated. While European and British law protects farmed fish from pain and distress at the time of slaughter, wild fish have no such protections. “A method that ensures immediate brain death is the most humane,” says Dr Lynne Sneddon, an expert on fish behaviour. She recommends that fish are stunned before spiking, but warns that it might not be possible logistically when killing fish on an industrial scale. In Britain ikejime has so far been restricted to fishermen on smaller boats using lines, as opposed to nets. In Japan, where demand for ikejime fish is much higher, commercial fishermen have streamlined the process and tuna caught by Australian and New Zealand fleets bound for Japanese markets is often killed using the method. Ikejime fish can command a higher price than fish killed in other ways: in Britain the mark-up is about 150%. As a recent editorial in Fishes, a scientific journal, put it: “when the welfare of animals is improved, both the quality of the product and its value increase – a rare case when the interest of the industry and the ethical standards underlying its activity walk hand in hand.”

Yoshinori is happy to pay more for quality: “If it works for fishermen’s lives and fish’s lives, it’s much better.” An increasing number of London chefs – and not just those cooking Japanese food – are coming round to his point of view. “It’s very trendy,” says Dylan Bean, the owner of Kernowsashimi, listing the top restaurants he supplies. For Michael Harrison, sous chef at Smoking Goat, a Thai restaurant in Shoreditch, the appeal of ikejime lies in its ability to extend the sell-by-date of the fish, letting chefs experiment with new techniques. He previously worked at a fishmonger in Australia which was pioneering “dry-ageing” fish, hanging it up for three or four weeks like meat – a process that can work only if the fish have been killed by ikejime.

Back on the Lizard, Wood pulls into Church Cove. Thatched cottages line a lush ravine that winds up a valley alive with the clack of jackdaws. The tide has risen and the steep slipway is shorter by a good five metres. Standing calf-deep in water, he tells me that ikejime isn’t cost-effective for every type of fish. Low demand for pollock, for instance, means the ikejime rate doesn’t justify the extra effort. But when it comes to the difference in taste between ikejime and non-ikejime fish, he’s sold. “I mean, I say I don’t do it with the pollock but if I’m going to eat it, I will.”

Photos: Harry Lawlor