The Four Groups and the 80% Method

The people who consistently cook fish well at home have one thing in common: they stop following the clock and start watching the fish.

That was a big change for me.

A thin sardine fillet and a thick piece of barramundi might both be called fish fillets, but they don’t cook in anything like the same way. Once I started looking at the fish rather than the timer, pan-searing became much more reliable.

It isn’t about complicated technique. It’s about understanding what is happening in the pan.

The Four Groups

I find it useful to think of fish in four broad texture groups. They aren’t absolute categories, but they’re a good starting point for deciding how I approach the cooking.

Group	Species	Target internal
Delicate and flaky	Sardines, sand whiting, Ōra King salmon	52–55°C
Delicate to medium	Coorong mullet, southern garfish, red mullet	55–57°C
Medium	Tommy ruff, Australian salmon, barramundi, flathead, coral trout	57–60°C
Medium to firm	Murray cod, nannygai, gurnard, kingfish, snapper, ling	60–63°C

I use these temperatures as a guide rather than a set of rules. A thermometer is useful, particularly with a thick piece of fish, but I use it to confirm what I’m seeing rather than replace it.

The 80% Method

This is probably the most useful thing I’ve learnt about pan-searing fish.

As the fish cooks, watch the flesh change from translucent to opaque. The cooked area gradually moves upwards from the surface touching the pan.

I generally turn the fish when that colour change has travelled about 80% of the way through the fillet.

The beauty of this method is that it automatically adjusts for thickness.

A sardine fillet might take less than 90 seconds.

A thick centre-cut piece of rock cod, coral trout or barramundi might take 10–12 minutes.

The clock doesn’t know the difference.

The fish does.

When the centre is still translucent and raw-looking, it needs more cooking. When the flesh is opaque, moist and flakes cleanly, you’re getting close.

If I see white protein pushing out onto the surface and the fish has become dry or rubbery, I’ve gone too far. That’s not a catastrophe—it’s useful feedback for next time.

Start With Dry Fish

Good pan-searing starts before the fish reaches the pan.

I pat the fish completely dry. Surface moisture has to evaporate before the fish can properly brown, so wet fish spends its early time in the pan steaming rather than searing.

With skin-on fish, I also run the back of a knife firmly along the skin to remove the thin smear layer. I’ve found this makes a noticeable difference when I want crisp skin.

I also like to take the chill off the fish before cooking. Not by leaving it sitting around for hours, but simply avoiding putting a very cold piece straight into a hot pan when I’m looking for an even result.

Give the Fish Time

One of the easiest mistakes to make is moving the fish too soon.

Once the fish has developed a crust, it will usually release from the pan more easily. If I try to lift it before it’s ready, I often leave the skin behind.

Heat matters too. The pan needs to be hot enough to brown the surface, but not so hot that the outside is burnt before the centre is cooked.

That’s where the four groups become useful. They give me a starting point for thinking about the heat and the final temperature, while the fish tells me what to do next.

Carry-Over Cooking

Fish continues cooking after it leaves the pan.

For thicker pieces, I’ll often remove it a few degrees below my target temperature and allow it to rest for two or three minutes on a warm plate.

The exact amount of carry-over depends on the thickness and how aggressively I’ve cooked it.

Again, the thermometer is confirmation.

The fish is still the teacher.

Read the Fish

Pan-searing isn’t really a recipe with a fixed cooking time.

The pan is giving me information all the way through.

The sound changes.

The surface changes.

The flesh changes colour.

The skin begins to crisp.

The fish starts to release.

Once I stop asking “How many minutes?” and start asking “What is the fish telling me?”, pan-searing becomes much easier to understand.

The fish changes.

The cut changes.

The cuisine changes.

But the fundamentals don’t.

Dry the fish. Understand the heat. Watch the colour change. Use the 80% method. Confirm with temperature. Allow for carry-over cooking.

Most importantly, watch the food.

That’s what makes pan-searing reliable rather than a gamble.