Double boiling is the one technique that punishes you for being impatient. The water around the inner pot has to stay just under a simmer for hours. Let it boil properly and the soup goes cloudy, the chicken shreds, and you have made stock instead of tong.
A steam oven solves this by removing the variable entirely. The cavity sits at whatever temperature you set it to, indefinitely, without you standing there adjusting a flame. I now do this more often than I used to, purely because it stopped being a chore.
What you need
- Half a kampung chicken, or 4 chicken thighs, bone in
- 10g dried cordyceps flower, rinsed
- 6 red dates, pitted
- 1 tbsp goji berries
- 4 dried scallops (optional, and worth it)
- 3 slices ginger
- 700ml water, or enough to cover
- Salt, added at the end and not before
Method
- Blanch the chicken in boiling water for two minutes, then rinse it under the tap. This is the step people skip and it is the reason their soup is grey. It takes four minutes total.
- Put the chicken, cordyceps flower, red dates, scallops and ginger into a lidded ceramic double-boiler pot or any heatproof bowl you can cover. Add the water.
- Cover. A lid matters more than you would think, because it stops condensate from the oven roof dripping in and thinning the soup.
- Set the oven to 100C, full steam. Cook for 3 hours.
- Add the goji berries for the last 15 minutes so they do not disintegrate.
- Season with salt only at the end. Salting early draws moisture out of the chicken and firms it up.
The result should be clear enough to see the bottom of the bowl through it. If it is cloudy, the blanch was skipped or the oven was hotter than it said.
The water tank thing
Here is the part that catches people out on their first long steam, and it is worth knowing before you buy rather than after. Domestic steam ovens generate steam from a small onboard tank, not a plumbed supply, and a three hour cook will empty most of them.
Mayer publishes this figure honestly: the MMSO17-RG has a 1.2 litre removable water tank rated for about an hour of use, with a low water indicator to tell you when to top it up. So a three hour soup means two refills. That is not a fault, it is how the category works, and an oven that tells you is better than one that quietly stops steaming.
The Teka HLC 8470 SC carries a 1 litre tank and runs a temperature range of 30 to 100C, with slow cook, sterilisation and regeneration among its 15 functions. That low end of the range is the interesting bit for soup people: 85C for a longer stretch gives you an even gentler extraction than 100C does, if you have the patience.
Both sit in Microwaves & Combi Ovens. Full-height alternatives are in Built-in Ovens.
What this replaces
An electric double boiler does the same job for less money and takes up counter space. A steam oven wins when you want the soup and a tray of something else going at once, and when you would rather not have another single-purpose appliance on the worktop. If you are only ever making soup, buy the double boiler. I would rather be honest about that than sell you an oven.
Questions people ask
Can I leave a steam oven running for three hours unattended?
The cook itself is designed for long cycles, but the water tank is the limit, not the oven. Check your model's stated tank duration and plan refills around it. An oven with a low-water indicator will prompt you rather than silently stopping.
Why blanch the chicken first?
Blanching removes the blood and protein that would otherwise coagulate into grey scum and cloud the soup. Two minutes in boiling water, then a rinse. It is the single biggest difference between clear soup and murky soup.
Does the pot need a lid inside the steam oven?
Yes. Without one, condensate from the cavity roof drips into your soup and dilutes it over three hours. A ceramic lid, or foil pressed tight, both work.
Can I do this in a combi oven instead of a full steam oven?
If it has a true 100 percent steam mode, yes. If its steam function only injects moisture into a hot fan cycle, the cavity is too hot and you will end up braising rather than double boiling.
How do I stop mineral scale building up?
Use filtered water if you have it, and run the descaling cycle when the oven asks. Models like the MMSO17-RG include descaling and self-drying functions for exactly this reason.
Cook next
Same appliance, opposite end of the effort scale: steamed egg with minced pork takes 15 minutes. Or read microwave, combi or steam oven if you are still deciding which to install, and how to measure for a built-in oven before you commit to a cabinet.