"Long-lining" for mackerel. © Des Colhoun

Matters of taste: Is the freshest fish always best?

Just like meat, the proteins and enzymes that are released post-mortem have an effect on flavour and texture
August 19, 2015

Family summer holiday in Cornwall. The usual early morning mizzle gave way to blue sky. Nine Steavensons and a couple of friends went mackerel fishing. The oldest among us was 80, the youngest was three. We chugged out of the Camel Estuary past Padstow into the near Atlantic where the deep blue sea rose and fell in rolling swells. The nice fisherman showed us how to hook the fishing poles through our elbows, let the weighted lines run out and jerk the line while reeling in to simulate the movements of small fish as bait. Alessandro, who is Italian and had never seen a mackerel before, had beginner’s luck and landed one straight away. It flapped on the deck flashing silver with green blue iridescent tiger striping along its back. I wanted to eat it immediately, culinary curious—how does the freshest possible fresh fish taste?

The mackerel was a taut slippery torpedo and difficult to grip. The fisherman looked on a little aghast: “Raw? I would better grill it nicely with a little butter!” But he leant me a knife and watched as I laid the mackerel on the top of the cooler box and sliced a wedge of fillet. The tail slapped.

“It’s still alive!” cried Adrien, appalled. The flesh was soft like gelatinous butter and the colour of blushing putty. I gingerly put a sliver in my mouth. “I can’t believe you’re eating it while it’s still alive!” Henry, who is eight, made a grimace; Orla, his little sister was already heaving over the side.

“It’s amazing!” I said. It was. It wasn’t at all like the shaved fillets of sashimi or carpaccio I was used to. The texture was squashy and creamy; the taste was a delicate rendering of essential elements: sea and blood and iron.

“Mackerel is my favourite fish,” Nathan Outlaw told me when I visited him in his new restaurant in Port Isaac a few days later. Outlaw is the only British chef with a Michelin-starred fish restaurant, and it is two-starred. “Mackerel is a fish you should eat as soon as you catch it. Sprats, herring, sardines, anchovies are all the same family and the fresher the better. I’ve had mackerel straight out of the sea, cured in sea water for 10 minutes. Wonderful! In the old days the fisherman would just add vinegar.”

Not all fish is best eaten super fresh. Just like meat, the proteins and enzymes that are released post-mortem have an effect on flavour and texture. Aside from the mackerel family, Outlaw told me that for most fish, the optimum window for eating is between two and five days old. Turbot will keep improving for up to 10 days, for example, while eating it fresh on the day it was caught “would be like eating a table,” said Outlaw. Similarly, on the few occasions he had served very fresh Dover sole, customers had complained that it was tasteless. A good rule of thumb is the oilier the fish, the quicker it will go bad.

The best process, he said, would be for the fisherman to gut a fish as soon as it is caught and then keep it whole on ice. This would mimic, to some extent, how animals are slaughtered: killed and then aged. But fishermen sell their catch by the weight and are unenthusiastic about doing the extra work of cleaning only to be rewarded with a lower price.

Outlaw pointed out that fresh fish is almost a misnomer. Day boats will catch coastal fish and crab and lobster, but trawlers after deep sea species such as cod, hake or skate will go out for up to a week at a time. The fish has been sitting on ice at the bottom of a boat for several days by the time it is landed and sold at auction. “Market fresh” is what they call it. Add another day or two for it to get to a reputable fishmonger’s slab, and more than a week for it to be transported, processed and packaged to end up in a supermarket chill counter.

Outlaw sources most of his fish from fishermen’s cooperatives in Cornwall. “We’re lucky here in Cornwall; we have the Gulf Stream so more of a diversity of fish than in the north of England.” Every fish has its own properties and peculiarities, and seasonality is also an important factor in determining texture and flavour. Mackerel is an active fish and has a lot of blood; sea bass is a scavenger with a different diet depending on the time of year. When the herring has a high season in November, Nathan buys in bulk, salts them for six weeks and then preserves them under oil, the same method as Mediterranean anchovies.

Back at the house we had a haul of mackerel. Some I skinned and fried; some I grilled until their skin bubbled and blackened. I cut ragged slices for carpaccio and dressed them very simply with salt and lemon juice and olive oil. And I made a Cornish ceviche with parsley and tarragon and spring onion and plenty of lemon and lime juice to “cook” it; cayenne to finish. “Why is it that fish tastes better by the sea?” asked my brother Michael as we all tucked in.

There was none left over for smoked mackerel pâté.