Cod

15 August 2017

Atlantic cod

Sometimes there’s a particular flower you walk past many times and vaguely notice but never really contemplate.

And then, one day, something makes you look again. Somebody stops you and invites you to smell it. Or you just happen to be in a reflective mood and it’s the thing that your eye falls upon.

And you notice how stunningly beautiful it actually is, all over again.

Growing up in the UK, it’s very easy to have something of that relationship with cod. It’s the ubiquitous fish of your youth, being the mainstay of every fish and chip shop in the land. That may make it the source of cherished memories of the unique blend of properly fried chips with the underlying aroma of malt vinegar, or maybe instead the stuff of nightmares carved out of nearly coagulated beef fat.

For me, the thing that made me look again was the introduction of sous vide into my life. Because before then, cod from a fish and chip shop was usually overcooked and was generally just bland - a vehicle for the salt and the batter and the guilty carb-pleasure of properly cut British chips.

Fish and chips
Food heaven ... or hell! (photo: Fiona Wilkinson

But a beautiful piece of cod loin, all shimmering and pure white, is an absolute joy when cooked exactly to perfection. For me, that is ‘oil poached’ in sous vide for half an hour to exactly 53 degrees C. It comes out soft and meltingly tender, white and flaky but as juicy and moist as you could possibly imagine. And in that state, the gentle flavour is a revelation - something precious that we’re so used to walking past without nary a glance.

Cod is a saltwater fish found in the Pacific and Atlantic oceans. That white, succulent and flaky flesh is a reflection of the fact that the fish is relatively inactive. It has very little fat and is easily digested. Perfect food if you’re on a diet, or just looking for a healthy option.

Sustainability

Its popularity has meant that cod stocks have been under immense pressure at times. Overfishing has led North Sea stocks to the brink of collapse, although measures taken to rebuild numbers have been effective enough that North Sea cod was re-added to the list of sustainable fish in July 2017.

Cod stays close to the bottom of the ocean along continental shelves, so it is often caught by trawling sea beds. As a process, this can be disruptive to marine environments and can result in by-catch of other fish, particularly redfish - which is suffering from low stocks. Trawlers in the Norwegian sea are required to use larger mesh nets to allow immature codling and unintended species to escape.

Atlantic cod is particularly sensitive to global warming and the resulting increase in sea temperature. This is one of a number of factors that have led to its disappearance from some fishing areas. 

The most sustainable fishing grounds for cod are Iceland and Norway, and that’s where most of the cod we see in the shops has come from.

Buying Cod

Look for farmed fish or line-caught cod that has been certified by the Marine Stewardship Council (MsC). 

The fresher the better. Generally, you’ll be buying fillets or loin, but if buying a whole fish the usual rules apply - choose fish that have a fresh smell of the sea and don’t smell fishy. The skin should be shiny and taut, the eyes should be clear and bright. It’s harder to tell if a fillet is fresh, but the flesh should be white and unblemished. Supermarket packaged fish will often be packed with gases that inhibit the decay of the fish to give them a longer life. It helps, but it doesn’t remove the imperative to find as fresh as possible.

Storage / preventing waste

Fish doesn’t keep well, so it’s one of the foods where you should buy what you can eat within a couple of days. If you’re buying a fish you’re not intending to eat the same day, the trick to storing it is to put it in ice in the fridge. Fish and the bacteria that spoil them are used to colder temperatures than the standard fridge provides. You can freeze fish on the day of purchase usually (if it’s bought fresh not frozen). Cod could be kept for up to six months frozen, but its flesh is likely to deteriorate from its best resulting in fish that is a little dry and fibrous. In that state, it’s food, but it’s not magic.

What it goes with

Cod’s gentle flavour makes it very adaptable for a range of different pairings. Dishes with rich sauces such as fish pie and clam chowder. It is often a feature of tomato-based dishes, or paired with buttery sauces. It is used a lot in Indian and other asian cooking. It goes well with assertive meats, like chorizo or pancetta.

And, of course, if you want to nurture those childhood memories you can stick it with some proper potato chips and a whack of salt and malt vinegar. Some people will tell you that, in these enlightened times, malt vinegar should never be used on any food at any time. But I say stuff them - you can’t mess with powerful things like memories.