Cod is soaked in cold water, below 8°C, with the skin facing up, for 24 to 48 hours depending on the thickness of the loin, changing the water three times a day. This is the stage that decides whether the cod is perfectly seasoned or arrives at the table too salty, dry, or falling apart.
What happens to the fish during soaking
Soaking removes excess salt and restores the water the fish lost during the drying process. During curing, cod loses about half its weight; when soaking, it recovers some of that weight and regains volume.
At the same time, the muscle fibers loosen. This is why well-soaked cod flakes beautifully after cooking, instead of breaking into short shreds or becoming tough.The golden rule: cold water
Ideally, the water should be kept below 8°C, which in practice means soaking in the fridge rather than on the countertop. In room-temperature water, the fish spends an entire day in a zone where it degrades, and the surface loses salt much faster than the interior—leaving it tasteless on the outside while remaining salty in the center.Step-by-step
- Rinse the loins under running water, rubbing them slightly to remove surface salt.
- Place them in a wide container and cover them well with cold water, with the skin facing up, without overlapping the pieces. The skin is fatty and impermeable: if placed face down, it acts as a barrier, and instead of the salt leaching into the bottom of the container, it accumulates inside the loin.
- Cover the container and place it in the fridge, where it stays throughout the entire soaking process.
- Change the water three times a day, every 8 hours. The water becomes saturated with salt and, after a certain point, stops removing more. For a 24-hour soak, that is three changes; for 48 hours, six.
- Allow 24 to 48 hours, depending on the size of the fish and the dish you are preparing.
How long, exactly?
Time is a function of thickness, not the clock. A thick loin needs the upper limit; thin pieces need the lower limit.
The most common mistake is giving all pieces the same amount of time. A thin piece left with a thick loin for 48 hours will come out completely tasteless and fall apart when handled, while the loin next to it still needs a few more hours. Soak pieces of similar thickness together and keep thin pieces separate.How to know if it's ready
Taste it before cooking. After the first 24 hours, take the thickest piece, rinse it, and cut a flake from the center, never from the edges—the edges lose salt first and can be misleading.The perfect seasoning is slightly salty. Cod that has lost all its flavor is over-soaked, and there is no way to restore the salt without ruining the texture. If it is still seriously salty, put it back in the water and add one more water change.
Never freeze soaked cod without tasting it first. Once frozen, there is no way to correct it.
Proper soaking is what allows you to shred the cod without it breaking—see Bacalhau à Brás — the traditional recipe, step by step.
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