Ask for fish and chips in most shops and you'll be asked one question before anything else: cod or haddock? Pollock barely gets a mention, yet it fills a great many fryer baskets, often under the vague menu heading of "fish". All three are lean white fish that take batter well. They are not interchangeable, though, and knowing the differences helps you get a better supper for your money.

Three Fish, Three Personalities

Cod is the benchmark. Thick fillets, big soft flakes, a clean milky sweetness that offends nobody. It's the default in much of southern England and the fish most people picture when they hear the word "chippy". Its weakness is moisture: cod holds a lot of water, and a wet fillet can steam its way through an otherwise decent batter.

Haddock is the northern favourite, and the one people get defensive about. Slightly sweeter than cod, with a finer flake and a flavour that lingers a little longer. Cooked well, it's the most interesting of the three. Cooked badly, it dries out faster than cod because the fillets tend to be thinner.

Pollock is the quiet workhorse. Two fish share the name: Atlantic pollock, also sold as coley or saithe, and the huge North Pacific Alaska pollock that supplies most supermarket fish fingers. Both are leaner, softer and milder than cod, and considerably cheaper. Coley was once the fish of hard-up weeks; it's now often the only affordable option on the board.

Flavour: A Close Call With a Clear Order

If cod is the blank canvas, haddock is the one with a bit of paint on it. Expect a gentle sweetness and a faint savoury depth that cod simply doesn't have. Some describe it as slightly nutty; others just say it tastes more like fish.

Pollock sits at the other end. Fresh from a good fryer it's pleasant and clean, but it's the least characterful of the three. Because it's leaner, it also holds up poorly to sitting around — a pollock fillet left under the lamp can turn slightly muddy in a way cod rarely does. Freshness matters more here than with the other two.

Texture and How It Behaves Under Heat

Cod flakes into large, tender chunks and pulls apart with a fork. Thick fillets stay juicy and hold their shape well; thin tail ends collapse into batter shards. Haddock flakes more finely and feels slightly firmer before cooking, then softens quickly — it has a habit of "flowering" open when you cut into it, which is either beautiful or annoying depending on how you feel about a tidy plate.

Pollock is denser and more uniform. Cut it with a fork and you get even, chunky pieces rather than a flaky cascade. It's forgiving of rough handling and travels well in a takeaway box. Overcook it, though, and it turns rubbery rather than dry, which is a harder fault to hide.

One rule beats all of this: thickness matters more than species. A 3cm fillet of pollock will eat better than a paper-thin slice of cod every time.

Batter Performance: Which One Clings Best

Batter sticks to dry protein and slides off wet protein. That's the whole story. Pat every fillet thoroughly with kitchen paper, then dust it lightly in seasoned flour before dipping — the flour gives the batter something to grip.

Pollock's leaner surface is the easiest to coat and rarely blows bubbles through the crust. Cod is the trickiest; its high water content produces steam that pushes holes in the batter, which is why proper drying and a hot, stable oil temperature matter most with cod. Haddock sits in between, and rewards a slightly thicker batter that protects its finer flesh.

Whatever you fry, rest the finished fish on a wire rack rather than kitchen paper. Paper traps steam underneath and undoes twenty minutes of good work.

Price and Value

  • Cod is usually the dearest, and the price swings most with the seasons and supply.
  • Haddock often costs about the same as cod, and in some regions it's dearer.
  • Pollock is reliably the cheapest of the three, sometimes by a wide margin.

Cheap doesn't mean bad. A fresh pollock, fried to order in a crisp batter, beats a tired cod fillet that's been sitting in the display case since lunchtime. If a menu just says "fish and chips" without naming the species, it's fair to ask — and worth asking, because you may be paying cod money for coley.

Sustainability: Ask Better Questions

Cod stocks are the most volatile of the three. Some regions are well managed, others have been under real pressure for decades, and the picture changes year to year. Haddock has generally been on firmer ground in the northeast Atlantic, and the vast North Pacific pollock fishery is among the most closely monitored whitefish fisheries in the world.

Rather than memorising status reports, do three things at the counter or fishmonger:

  1. Look for a credible certification label, such as the blue Marine Stewardship Council tick.
  2. Ask where the fish came from and how it was caught. Hook-and-line and other selective gear usually do less damage than heavy trawling.
  3. Vary what you buy. Eating only cod puts pressure on one stock; rotating between species spreads the demand.

Which Fish for Which Job

A quick way to decide:

  • Classic chippy supper, eaten in: cod in the south, haddock in Scotland and the northeast. Order whichever is the local speciality.
  • Feeding a crowd on a budget: pollock, without apology.
  • Maximum flavour: haddock.
  • Kids and cautious eaters: cod, or pollock if the flavour of fish is the problem.
  • Fish cakes, pies and tacos: pollock. It holds its shape in a mix and costs less when the seasoning does the talking.

Frying Tips That Work for All Three

  1. Buy fillets of even thickness, roughly 2–3cm. Ask the fishmonger to cut them for you if they're uneven.
  2. Dry the fish properly, then season it. Salt on the surface now, not only in the batter.
  3. Dust with flour before dipping. It's the difference between a crisp shell and a bald fillet.
  4. Keep the batter cold and don't overmix it. Lumps are fine; a smooth, glutinous batter fries tough.
  5. Fry at around 180°C (350°F) and don't crowd the pan. Two fillets at a time in a domestic fryer.
  6. Drain on a rack, salt immediately, and serve within a few minutes. This is the one dish that genuinely doesn't wait.

The Practical Answer

If you want the safe, familiar choice, buy cod. If you want more flavour and don't mind a slightly more delicate fillet, buy haddock. If you want value and a fish that fries predictably, buy pollock — and if the shop is honest about what it's selling, that's a meal worth having.

In practice, the freshest fish on the counter beats the most fashionable one every time. Ask what came in today, ask for it cooked to order, and judge with your own mouth rather than the menu's reputation. Fish is a genuinely good source of protein and other nutrients, but deep-fried food is best treated as an occasional pleasure; if you have specific dietary concerns, a doctor or dietitian is the right person to ask.

Photo: ReinhardThrainer / Pixabay