Why does my fish release so much water in the pan?

Four different sources of the liquid that stops fish browning — ice glaze, added water, thaw drip and protein squeeze — how to tell which you have, and what to do about each.

Difficulty: beginner
Time: 10 min
Read: 4 min

Short answer

Either the fillet had water added to it before you bought it, or it was not dried and drained after thawing, or the pan was not hot enough to evaporate what came out. Check the ingredients list for added water, thaw on a rack over a plate, dry the fillet hard on both sides, and get the pan properly hot before it goes in.

A fillet sitting in a grey puddle, poaching itself instead of browning, has one of four causes and they need different answers. Two of them are decided at the shop rather than at the hob, which is why some people never solve it by changing technique.

Step by step

Read the ingredients list before you blame your cooking.If a pack of fish lists anything other than fish — water, salt, stabilisers, sodium tripolyphosphate, E451 — then water has deliberately been added and will come back out in the pan. Fillets sold as plain fish list one ingredient.
Distinguish glaze from added water on frozen fish.Frozen-at-sea fillets carry a thin ice glaze to stop freezer burn, which is normal and small. Added-water product is a different thing and the pack must declare the percentage. A high figure means you are paying fish prices for brine.
Thaw on a rack, not in a puddle.Fish sitting in its own thaw drip reabsorbs some of it and stays saturated. Put it on a rack over a plate in the fridge so the liquid drains away and cannot be taken back up.
Dry it properly, both sides, right before it cooks.Press it firmly between kitchen paper. This is not a wipe — take it until the paper comes away only slightly damp. Skin especially, because that is the face going down first.
Salt the surface just before cooking, not half an hour before.Salt draws moisture out of the surface. Applied a few seconds before the pan, it seasons; applied twenty minutes before, it puts a film of brine on exactly the face you wanted dry. The exception is a deliberate long dry-brine uncovered in the fridge for several hours, which ends up drier than where it started.
Get the pan hot and do not crowd it.Whatever moisture does come out must be able to evaporate faster than it accumulates. A cool pan or three fillets crammed in drops the temperature below evaporation point and the fish stews.
If liquid does collect, get it out.Tip the pan and spoon it off, or lift the fish, wipe the pan and put it back. Cooking a fillet on in its own liquid guarantees a pale grey surface.

Tips

Previously frozen fish always releases more than never-frozen fish, because ice crystals rupture cell walls and the water that was held inside the cells is now free. Nothing at the hob fully fixes that — it is a property of the fillet.
The white curd that appears on salmon is albumin, not water. It is squeezed out by muscle contraction and means the fish went too hot or too far. Lower heat and less time reduces it.
Very cheap prawns and scallops are the worst offenders for added water, because both are sold by weight and both take up brine readily. Look for "dry" scallops and prawns with fish as the only ingredient.
If you cannot get a dry surface — say the fish came out of a bag of stew-grade fillets — stop fighting it and choose a wet method instead. Curry, chowder, pie or poaching does not care.

Common mistakes

Adding fish to a pan straight from a thawing bowl — The surface is saturated and the pan temperature crashes the moment it goes in. You get boiled fish with no crust and a puddle, and the fish overcooks while you wait for colour that will never come.
Buying on price without reading the ingredients — Added-water fish can be a substantial share of pack weight. You pay for the water, you cook it out, and you end up with less fish and a worse texture than a plain fillet that looked dearer per kilo.

If it doesn't work

Grey puddle within a minute of the fish going in

Cause: Wet surface plus a pan that was not hot enough — Fix: Lift the fish out, wipe the pan dry, reheat it properly, re-dry the fish and start again. The fish will still be fine.

Fillet shrank dramatically and feels spongy

Cause: Added-water product, or fish that has been frozen and thawed more than once — Fix: Nothing at the hob will recover it. Use it in something sauced and check the ingredients list next time.

Cod that fell into wet mush

Cause: Over-thawed, previously frozen, or a long-thawed fillet at the end of its life — Fix: Use it for fishcakes or a pie, where texture is rebuilt. Buy frozen and cook from frozen or from a short controlled thaw.

White curd all over cooked salmon

Cause: Albumin squeezed out by heat that was too high — Fix: Cook at a lower temperature and pull it earlier. A brief salt brine before cooking also reduces it noticeably.

Questions people ask

Does soaking fish in salt water before cooking help?

Yes, briefly. Ten minutes in a light brine — roughly a tablespoon of salt in a litre of water — firms the surface, seasons the fish and measurably reduces albumin leakage on salmon. Dry it thoroughly afterwards. Long soaking does the opposite and waterlogs it.

Is added water in fish legal?

Yes, as long as it is declared. UK and EU rules require added water above a threshold to be shown in the name and the ingredients list, with the percentage stated. It is legal, disclosed, and easy to avoid once you know to look.