Sea Bass Mousseline (Fish Mousse)

While rare to see on menus these days, fish mousse is a classic recipe that every culinary aficionado should know. This sea bass mousseline is a classic European preparation that only requires six ingredients – so this is primarily a methodology article.

Sea bass mousseline is a type of forcemeat that one rarely sees served these days. Well, where I live in Europe it is still quite common even at casual restaurants, but in America I’ve only ever seen it at fancy places. To be honest, fish mousse sounds off-putting to some, but it is a absolutely wonderful appetizer, especially with a few slices of high quality bread.

Unlike my salmon mousse, which is a 1970’s style American cocktail party canape, this sea bass mousseline is, at its root, classically European. Actually this recipe for sea bass mousse is adapted from one by Taras Khrushch, one of the top Ukrainian chefs and head of the restaurant at 11 Mirrors in Kyiv. Therefore it is slightly different than the French style of mousseline.

What Is A Mousseline?

Mousseline can refer to a few different things in the culinary world. There is the sauce of hollandaise mixed with cream, there is the pastry filling made of pastry cream and whipped butter, and there is the forcemeat. And I’m sure you know by now this recipe refers to the latter.

A fish mousseline is made by blending fish meat with other ingredients like starches, creams, egg, bread, and more. There are plenty of different ways to make a fish mousse but they almost always have fish, cream, and eggs (which acts as a binder). Some people also prefer to fold in whipped egg whites to made the final dish extra airy, but that is entirely optional.

How To Make A Sea Bass Mousseline

I serve the sea bass mousseline on a bed of scallion and shallot cream, but you can pair it with whatever you like. I also add some homemade cranberry sauce which I had left over after making a duck with corn cream and cranberries. I thought tart cranberries would pair well with fish mousse…and they do!

As for the actual mousseline there are only six ingredients; I provide substitutions for some down below.

Ingredients

• 160 grams Sea Bass – You can use any saltwater fish you want for this recipe. I recommend against using freshwater fish as the fish is only cooked by the hot potato, which may not kill parasites found in freshwater fish.
• 210 ml Sour Cream – You can use regular sour cream, but if you can find smetana that is a better option as it has a higher fat content than American style sour cream. If you cannot find smetana you can also use creme fraiche.
• 170 grams Potato – Peeled and diced
• 40 ml Vegetable Oil – I use sunflower oil, but any neutral oil will work . I would avoid olive oil as it imparts too much of it’s own flavor which competes with the fish.
• 2 sheets Leaf Gelatin – You can use powdered gelatin if you prefer, just make sure to use the proper amount.
• Salt – To Taste.

Instructions

The first step is to fillet your sea bass. If you were able to buy fillets already prepared then you can skip this step. In another bowl add the leaf gelatin and some water to soften.

In a bowl add the sea bass meat, sour cream, gelatin. Blend everything together with a stick blender (you can also use a standing blender or a food processor) until smooth.

Press the sea bass mousse through a sieve. Discard any lumps or pieces that didn’t go through, you do not want bits and pieces in your mousse.

Boil your potatoes until soft and rice them and whip them until smooth. Do not worry about making them gluey, this is almost like an aligot but replacing the cheese with fish. Since this recipe does not use egg like in a French style mousseline, the potato and gelatin are acting as the binders.

Add salt and fold the fish into the potato until homogenous.

Move the contents of the bowl to a sealable container and press down a layer of plastic wrap. This will prevent a skin from building and ensuring you have a smooth and luscious mousse when ready to serve.

Place the container into the fridge and let set for 6 hours, or overnight.

How To Serve

You can serve this fish mousseline a variety of ways. I like to use an ice cream scoop to serve a little mound like an appetizer. To make the green onion cream I blended up two bunches of spring onion with one shallot and about a cup of heavy cream. Then I passed it through a sieve. A few tablespoons of the sauce in a shallow bowl makes a perfect bed to rest the mousseline atop.

You can also serve this mousse already spread on slices of bread or toast as a canape or passed hors d’oeuvres.

How Long Does Fish Mousseline Last

If properly sealed this sea bass mousseline will hold for three days in the refrigerator. I do not recommend consuming it after that although you can always do the smell test and decide for yourself.

If you do not think you will finish this mousse in three days you can absolutely freeze it. It will lose some of its texture but will still taste delicious.

What Fish Make The Best Mousseline?

When making a fish mousseline I always recommend a sea fish. However with proper preparation you can make this with freshwater fish as well. Some of my favorite fish for mousse include sea bass (obviously), halibut, Patagonian toothfish, escolar, and sablefish (aka black cod).