Steaming a whole fish is where a steam oven earns its place over the wok-and-plate method most of us grew up with. The wok is not the problem. Headroom is. A 700g seabass sitting on a plate, inside a wok, with the lid on, is a tight fit, and every time you lift that lid to check on it the temperature drops and the fish stalls.
A steam oven holds 100C across the whole cavity and lets you look through the door instead of opening it. That is the entire advantage. It is not a small one.
What you need
- 1 whole seabass, 600g to 800g, gutted and scaled
- 2 sour plums, lightly crushed, plus a tablespoon of the brine
- 1 medium tomato, in wedges
- 2 leaves salted mustard green (kiam chye), rinsed and sliced
- A thumb of ginger, half in coins, half julienned
- 2 stalks spring onion, cut into lengths
- 3 soaked shiitake mushrooms, sliced (optional)
- 1 tbsp light soy sauce, 1 tsp sesame oil, a pinch of white pepper
Method
- Pat the fish dry, inside and out. Wet skin steams into something slack.
- Lay the ginger coins and spring onion whites on a heatproof plate and rest the fish on top of them. Lifting the fish off the plate lets steam get underneath, so the belly cooks at the same rate as the back.
- Tuck the sour plums, tomato, kiam chye and mushrooms around and over the fish. Spoon the plum brine across it.
- Set the oven to 100C on full steam. Most steam ovens do not need a preheat for this, though preheating does no harm.
- Steam 12 minutes for a 600g fish, 15 for 800g. Test behind the head at the thickest point: the flesh should part cleanly off the bone.
- Pour off the collected liquid if it looks cloudy, then dress with the soy, sesame oil and white pepper. Scatter over the julienned ginger and the spring onion greens.
Serve it immediately. Fish that sits goes rubbery, and no amount of sauce fixes that.
Timing by weight
| Fish weight | At 100C, full steam |
|---|---|
| 500g | 10 minutes |
| 600g | 12 minutes |
| 700g | 13 to 14 minutes |
| 800g | 15 minutes |
| 1kg | 18 minutes, then check |
Starting points, not laws. A thick-bodied fish takes longer than a flat one of the same weight.
Which ovens actually suit this
Two things matter for a whole fish: how wide the cavity is, and whether the steam is real steam rather than a splash of moisture injected into a hot fan oven.
The Fujioh FV-ML75 is a 73 litre multifunctional steam oven with dual convection fans and separate top and bottom temperature control. Capacity is the useful part here. A 73 litre cavity takes a 1kg fish on a full-width plate without you having to angle it in.
The Bosch CDG714XB1 goes the other way. It is a dedicated 38 litre steamer in a 60 by 45cm housing, so it is a compact appliance rather than a full-height oven. Bosch says you can cook on three levels at once without the odours from different dishes mixing, which is exactly the case for steaming fish above a tray of kai lan and having both ready together. Smaller cavity, though. A 1kg fish is asking a lot of it.
If you want the fish and a probe, the Electrolux KOAAS3ST is a 70 litre full-steam oven with a food probe built in, which removes the guesswork on a thick fish.
The wider range sits in Built-in Ovens and Microwaves & Combi Ovens.
Before you buy one for this
A 45cm-tall compact steamer and a 60cm-tall oven need different cabinet apertures, and changing your mind late in a renovation is expensive. Our guide on choosing between a microwave, combi and steam oven covers which suits which kind of cooking, and what 66, 71 and 76 litres actually buys you is worth ten minutes if you cook whole fish or whole birds often.
Questions people ask
Do I need to preheat a steam oven for fish?
No. Steam reaches temperature within a minute or two of the cycle starting, so a cold start costs you almost nothing on a 12 minute cook. Preheating matters far more for baking than for steaming.
Why is my steamed fish watery?
Usually one of two things. The fish was not patted dry before it went in, or the plate was flat, so condensate pooled around the fish instead of draining off. Rest the fish on ginger coins and use a plate with a slight lip.
Can I steam fish from frozen?
Thaw it first. Frozen fish releases water as it cooks, which dilutes the plum and soy and leaves the flesh spongy. Thaw overnight in the fridge, then pat very dry.
Is a steam oven better than a bamboo steamer?
For a whole fish over 600g, yes, mostly on size and because you can watch it without opening anything. For a small fish or a few fillets, a bamboo steamer over a wok is faster to set up and there is nothing to descale afterwards.
How do I get rid of the fish smell afterwards?
Run the oven empty on steam for a few minutes and wipe the cavity while it is still warm. Fish oil sets hard once it cools. Ovens with a steam-assisted clean cycle, like the FV-ML75, turn this into a two minute wipe instead of a scrubbing session.
Cook next
If you like what steam does to fish, see what it does to soup: double-boiled chicken soup in a steam oven, which runs for three hours unattended and never boils.