We make fish soup with the Thermomix® on days when lunch should feel like more than just a weekday meal. 25 minutes from lemon to table, and the key trick is not in the stock but in the timing: the fish only goes in for the final 4 minutes. Everything before that would give you dry, flaking protein in pale broth.
We have been making this soup for years in two versions. The simple version with 500 g cod, peas and double cream is the weekday option: creamy, dill-forward and done in 25 minutes. The Mediterranean variation with salmon, cod and prawns, a little saffron and a roasted tomato base is what we put on the table at weekends when we have guests. Both approaches use the same method, and we walk you through it here.
Fish Soup with the Thermomix®
Ingredients 0 / 13 ✓
- 1 lemon
- 500 g cod fillet
- 1 tsp salt
- 1 tsp pepper
- 2 garlic cloves
- 1 red pepper
- 1 stick leek
- 30 g butter
- 20 g tomato puree
- 800 g vegetable stock
- 4 sprigs dill or other fresh herbs
- 300 g double cream
- 200 g peas frozen
Instructions 0 / 7
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1
Marinate the fish.
Wash the lemon, finely grate 2 tsp of zest, then halve and juice it. Drizzle the fish fillets with lemon juice and season with salt and pepper.
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2
Chop the garlic.
Peel the garlic, place in the mixing bowl and chop for 3 seconds / speed 8.
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3
Sweat the vegetables.
Wash and trim the pepper and leek, cut into pieces, add to the mixing bowl together with the butter and tomato puree, chop for 5 seconds / speed 5, then sweat for 4 minutes / Varoma / reverse direction / speed 1.
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4
Cook the soup.
Add the vegetable stock and cook for 8 minutes / 100°C / reverse direction / speed 1.
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5
Chop the dill.
Meanwhile, wash the dill, shake dry and pick the leaves. Finely chop half of it.
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6
Cook the remaining ingredients.
Add the double cream, peas, fish, lemon zest and chopped dill and cook for 4 minutes / 100°C / reverse direction / speed 1.
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7
Serve.
Serve scattered with the remaining dill.
Tip: Not just cod, but other types of fish or seafood also work well in this fish soup. Put together your own combination.
Video
Nutrition per serving
Why the fish can only go into the mixing bowl at the end
Fish is cooked through at 100°C in 4 to 6 minutes. Cod, salmon and prawns all need less time than it takes the stock to develop flavour. If we add the fish from the start, three things happen at once: the protein over-sets and turns dry, the pieces break apart in the reverse direction of the Thermomix® into flakes, and the flavour migrates entirely into the broth. What is left is soupy cotton wool with a fish taste, not actual pieces of fish.
We worked out the clean solution over many attempts. First chop the garlic, then sweat the pepper and leek with butter and tomato puree, then add 800 g vegetable stock and let it cook for 8 minutes. Only after that do the double cream, peas and fish go into the mixing bowl, and the whole thing cooks for exactly 4 minutes at 100°C, reverse direction, speed 1. Four minutes are enough because the fish is cut into 2 cm pieces and the soup is already hot. Cook longer and you get dry cod.
Salt after cooking, never before
We deliberately split the 1 tsp of salt from the ingredient list across two stages. A pinch goes on the raw fish along with the lemon juice as a marinade, and in the 5 minutes of resting time it draws out very little moisture. The rest goes into the finished soup just before we season to taste. If we were to salt the fish fully before cooking, the salt crystals draw liquid out of the flesh by osmosis, and we end up with woody pieces in the soup. The same goes for pepper from the mill: into the finished broth, not onto the raw fish.
The Mediterranean three-fish version in detail
For the Mediterranean character, we replace the 500 g of cod with a mixture: 200 g cod, 200 g salmon (loin if possible, not belly) and 100 g peeled raw prawns, thawed. Three fish, three textures. The cod stays firm and flaky, the salmon lends colour and fat to the broth, and the prawns add a sweet, briny note. Important: cut all three into even cubes of about 2 cm so they are all ready at the same time in the 4 minutes.
We adjust the flavour profile at three points. During the sweating stage, 2 ripe tomatoes (diced) go in alongside the tomato puree. With the stock, we add 1 sachet of saffron threads (about 0.1 g), which gives a golden colour and the typical bouillabaisse note. Instead of dill we use flat-leaf parsley and a few fennel seeds, about 1/2 tsp. We leave out the peas and instead add 100 g black olives (stoned and halved) at the end. We reduce the double cream to 200 g so that the tomato and saffron character does not get lost.
What we got wrong in our early attempts
Putting frozen fish straight into the mixing bowl
If you use frozen fillets, you must thaw them completely first and pat them well dry. Thaw water in the mixing bowl dilutes the soup, and frozen pieces cool the finished broth down so much that the 4 minutes of cooking time is no longer enough. The result: translucent fish in the middle. We thaw the fillets overnight in the fridge, which is the gentlest method. Quick-thawing in lukewarm water works in about 30 minutes if needed, but then drain on kitchen paper first.
Leek chopped too coarsely
In our first attempt we had only cut the leek into thick rings and chopped it at speed 5. The result was tough leek strips that were unpleasant to eat. These days we cut the leek into 1 cm rings, wash it thoroughly (soil sits between the layers) and add it to the mixing bowl together with the pepper. 5 seconds at speed 5 is enough, and the 4 minutes of sweating does the rest.
Adding the cream too early
Double cream and 100°C over a long period are not friends. If we add the cream to the stock and let it cook for the full 8 minutes, it curdles at the hot spots along the mixing bowl wall. Small flecks form and the soup looks milky and grainy instead of creamy. That is why the cream goes into the mixing bowl in the same step as the fish, for exactly 4 minutes at reverse direction, speed 1. That is long enough to bind the soup but short enough that nothing separates.
Further ways to adapt the basic recipe
The Finnish salmon version (Lohikeitto): Instead of pepper and tomato puree, use 200 g waxy potatoes cut into 1 cm cubes, one bay leaf and more dill (double the amount). Replace the cod with 500 g salmon fillet. This gives you Finnish salmon soup, which is served in Scandinavia at any time of year.
Asian with coconut milk and lime: Swap out the double cream for 400 g coconut milk. Instead of dill, use 1 tbsp curry paste (red or yellow) and 1 stick of lemongrass (cook in the broth and remove before serving). Use lime juice instead of lemon and fresh coriander to scatter over. Surprisingly good with cod and prawns.
With Pernod or anise liqueur: Add 30 ml Pernod after sweating the pepper, reduce for 30 seconds without the lid at 100°C, then add the stock. The anise note pairs very well with fennel and saffron in the Mediterranean version.
What we put on the table alongside it
The classic version with peas and dill goes well with fresh farmhouse bread or a spelt baguette made in the Thermomix®, toasted with a little butter. We like to serve the Mediterranean three-fish soup with rouille (garlic mayonnaise with saffron) and toasted baguette slices to dip into the soup. For something simpler, a fresh tzatziki as a starter and a glass of dry white wine alongside works nicely. A Sauvignon Blanc or a light Riesling both do the job well. For a vegetarian starter in the same spirit, we recommend our tomato soup made in the Thermomix®, which covers a different soup day.
Serve fresh, leftovers are better the next day
Fish soup with fully cooked fish needs care when reheating. In the fridge, the soup keeps for 1 to a maximum of 2 days in an airtight container. If you want to be safe, remove the remaining fish pieces after eating and store them separately. When reheating, bring the broth slowly to 70 to 80°C in a saucepan, never at a rolling boil or the fish will dry out completely. Add the fish pieces only at the end and leave them to warm through for just 2 minutes.
We do not recommend freezing. The cream base separates when thawed and the fish becomes mushy when reheated. If we know not everything will be eaten, we prefer to make half the quantity. The recipe halves without any trouble, though the cooking times reduce slightly: 6 minutes for the broth and 3 minutes for the fish.
What sets our fish soup apart from Cookidoo and other recipe sites
Goes well with: Spelt baguette and Ciabatta.
The official bouillabaisse on Cookidoo® by Vorwerk takes one hour and 25 minutes, uses fish stock, white wine, mussels and king prawns. We are done in 25 minutes, use regular vegetable stock and build the Mediterranean character through saffron, tomato and fennel seeds. The other popular recipe sites cook the fish for 10 minutes at 90°C in a wine-based clear broth without cream or tomato. We cook for 4 minutes in reverse direction at 100°C and offer two versions in one recipe: the creamy weekday version with peas and dill, and the Mediterranean three-fish version with saffron for guests. We deliberately leave out the wine because cream combined with acidity at the bowl wall can cause it to split. Anyone who wants anise depth can use the Pernod tip from the variations above.
For more soups made in the Thermomix®, take a look at our tomato soup and our potato soup. Both follow the same logic as this fish soup: first build the broth base, then add the delicate ingredients right at the end.
