How to Desalt Cod: 3 Methods (30min, 2h and 24h)

Salted cod is one of the great treasures of Mediterranean cuisine. It is used in emblematic recipes such as bacalao al pil-pil, vizcaína, Catalan esqueixada, or Lenten fritters. But all that culinary potential depends on a preliminary step that many underestimate: desalting the cod correctly.

Poorly desalted cod can ruin any recipe, no matter how good the raw ingredients. Too much salt and the dish is inedible. Too little and the cod is bland, without character. At Bacalalo, we have been working with quality cod since 1990 at the Mercat del Ninot in Barcelona, and the question our customers ask us most often remains the same: how to desalt cod quickly and well at home?

Today we explain it in detail: the traditional method, the quick method for emergencies, the milk trick, the exact times according to each cut, and the mistakes you should avoid. This way, you can enjoy its authentic flavor without over-salting or losing texture.

Why is it necessary to desalt cod?

Salted cod has undergone a curing process that can last between 3 months and over a year. During this process, salt penetrates deeply into the muscle fibers of the fish and extracts most of its water. The result is a piece with a salt concentration that can exceed 20% of its weight, a level that makes it completely inedible as is.

Desalting works on a physical principle called osmosis: when you submerge cod in fresh water, the difference in salt concentration between the fish meat (very salty) and the water in the container (salt-free) causes the salt to migrate from the cod to the water, seeking to balance both concentrations. At the same time, the cod absorbs clean water and regains some of the hydration it lost during curing.

If you don't desalt the cod or desalt it insufficiently, this is what happens:

• The taste is aggressively salty, completely masking the delicate flavor of the fish and the other ingredients in the recipe.
• The texture remains rigid and rubbery, because the fibers have not regained their natural hydration.
• Health risk: an excessive concentration of salt in a single meal can be problematic, especially for people with hypertension or kidney problems.

The goal of desalting is to bring the cod to a residual salinity of between 1% and 2%, a level where the salt is present but balanced: it enhances the fish's flavor without overpowering it. Perfectly desalted cod has a mild but perceptible saltiness, like a well-seasoned dish by a good chef.

Materials and preliminary preparation

Before starting the desalting process, prepare the following:

1. A large container: the cod must be completely submerged, with excess water above it. A small container causes the water to saturate with salt too quickly.
2. A rack or colander inside the container: this is a trick that makes all the difference. If you place a rack, drainer, or colander at the bottom of the bowl, the cod is elevated, and the salt it releases falls by gravity to the bottom, without coming back into contact with the fish. This is the method we use at the fishmonger.
3. Very cold water: always cold tap water. In summer, if the tap water temperature is high, add a few ice cubes with each change to keep it below 8°C.
4. Fridge with space: cod should always be desalted in the fridge, between 4°C and 8°C. At room temperature, the process is faster, but the risk of bacterial proliferation is too high.
5. Initial rinse: before submerging the cod, rinse each piece under the tap for 30-60 seconds, gently rubbing with your fingers to remove surface salt and visible crystals. This step speeds up desalting by removing the most concentrated layer of salt from the start.

Professional tip: group pieces by similar thickness. If you mix thick fillets with flakes in the same container, the flakes will be perfect at 12 hours while the fillets will need double that time. Use separate containers if you have cuts of very different thicknesses.

Desalting times according to the cut

Desalting time depends directly on the thickness of the piece and the intensity of the curing. This table shows the reference times for desalting in the fridge, with water changes every 8 hours:

Important note: these times are indicative. Curing can vary from one supplier to another, and cod that has been salted for more months will need more time. Therefore, always taste before cooking (we explain how later).

Remember to always place the pieces with the skin facing up. The skin acts as a partial barrier and slows down salt loss on that side. If you place it facing down, the flesh side desalinates quickly but the skin side retains too much salt, resulting in an uneven outcome.

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Quick method (when you don't have time)

You forgot to soak the cod and need it today. It's not ideal, but there are solutions. Here are three quick methods to desalt cod in a few hours, ordered from best to worst result:

1. Frequent water change method (4-6 hours)

This is the most reliable quick method. The key is simple: the more often you change the water, the faster the cod desalinates, because fresh water (without salt) maximizes the osmotic gradient.

1. Rinse the cod thoroughly under the tap for 2-3 minutes, gently rubbing to remove all surface salt.
2. Cut into smaller pieces if the piece is large. The thinner the thickness, the faster osmosis penetrates.
3. Submerge in plenty of cold water in the fridge with the skin facing up.
4. Change the water every hour for 4-6 hours. With each change, briefly rinse the cod under the tap before re-submerging it.
5. Taste after 4 hours: cut a piece from the thickest part and taste it. If the salt level is acceptable for your recipe, remove it.

This method works well for flakes, thin fillets, and medium fillets cut into portions. For whole thick fillets, the inside may still be salty even if the surface is fine.

2. Initial lukewarm water method (3-5 hours)

Use a short initial soak with lukewarm water (between 30°C and 40°C, never hotter) for 30 minutes. Lukewarm water accelerates osmosis because molecules move faster at higher temperatures. After 30 minutes, switch to cold water and continue in the fridge with changes every hour.

Important: lukewarm water is only used for the first 30 minutes. If the cod spends too long in hot water, the proteins start to coagulate and the texture becomes rubbery and irreversibly tough. It's an emergency solution, not a regular method.

3. Blanching method for flakes

This method is only valid for cod flakes or very small pieces. It involves bringing water to a boil, removing it from the heat, and submerging the flakes for 2-3 minutes. Then, drain them and immediately transfer them to cold water with ice. The thermal shock extracts surface salt very quickly.

Blanching does not replace complete desalting: it reduces the salt level quickly but the texture becomes slightly cooked. It is useful if you are preparing cod croquettes, fritters, or brandade, where the cod is flaked and mixed with other ingredients. Do not use it for recipes where the texture of the fillet is key (pil-pil, oven, grill).

The milk method: when to use it and when not to

Soaking in milk is one of the most popular tricks for desalting cod, but it is not always necessary or convenient. We will explain exactly when it is worthwhile and when it is better to stick to water.

How it works

The proteins in milk, especially caseins, partially bind to salt compounds and soften the desalting process. In addition, the fat in the milk provides a touch of creaminess and a slight sweetness that counteracts residual salinity. It's not that milk desalinates faster than water, but rather that it softens the final result.

When to use it

• Cod with very intense curing: if you notice that after 24 hours of normal desalting the cod is still quite salty, replace the last water change with cold whole milk and leave it for 2-3 hours in the fridge.
• Creamy recipes: for brandade, croquettes, or gratin cod, the step through milk provides extra smoothness that improves the final dish.
• As a final step: professionals who use milk reserve it for the last hours of desalting, not for the entire process.

When it's not necessary

• Cod with standard curing: if you desalt with enough time and change the water correctly, water alone gives a perfect result.
• Recipes with strong sauces: if the cod is going to be cooked with sofrito, tomato, peppers, or an intense pil-pil, the nuance of the milk is completely lost.
• Flakes and shredded cod: small pieces desalt so quickly in water that milk does not make an appreciable difference.

How to use it correctly: always use cold whole milk (not skimmed, because fat is part of the effect). Replace one or two of the last water changes with milk. Do not use hot milk. And after soaking in milk, dry the cod well with kitchen paper before cooking.

How to tell if the cod is ready

The times in the table are approximate: the definitive test is always organoleptic. Here are two ways to check that the desalting is correct:

The cooked piece test (the most reliable)

Cut a small piece from the thickest part of the cod (this is the part that takes the longest to desalt and will give you the real information). Put it in a little unsalted water and microwave it for 15-20 seconds, or briefly blanch it in boiling water. Taste it. The cod should have a mild and pleasant saltiness, like a well-seasoned dish. If it is excessively salty, it needs more time. If it tastes like nothing, you have over-desalted it.

Tasting raw cod also works, but cooking slightly concentrates the flavor and gives you a more accurate picture of how it will turn out in the final dish.

The texture test (complementary)

Press the cod flesh with your finger. Well-desalted cod has these characteristics:

• Flexible to the touch: the flesh yields slightly when pressed, instead of being stiff as it was when very salty.
• Flakes that separate: if you gently pull the flesh, the cod's natural flakes begin to separate. If the piece is still compact like a block, it probably still retains too much salt inside.
• Homogeneous pearly white color: well-desalted cod loses the yellowish translucent appearance of salted pieces and becomes opaque and white.

Signs that you have over-desalted it

If the cod has lost too much salt, you will notice that the flesh is soft, without structure, and the flavor is flat and bland. If this happens, you can partially compensate by adding salt to the dish during cooking or using a more flavorful broth. It's not ideal, but it works.

Common mistakes to avoid

After more than 30 years selling salted cod, these are the mistakes we see most frequently. Avoid them and the result will be much better:

Error 1: Desalting at room temperature

This is the most dangerous and most frequent mistake in summer. Cod soaking at room temperature, especially if it exceeds 20°C, becomes a breeding ground for bacteria. In a few hours it can start to smell bad and deteriorate. Always in the fridge, without exception. If you don't have space, use a cooler with ice.

Error 2: Not changing the water frequently enough

Water absorbs salt until saturated. When it reaches equilibrium in concentration with the cod, the osmotic process stops completely: it doesn't matter how many more hours you leave it, it won't desalt another gram. Water changes renew the osmotic gradient. With the traditional method, at least every 8 hours; with the quick method, every hour.

Error 3: Using hot water to speed things up

Hot water does accelerate salt extraction, but at a price that isn't worth it. Above 50-60°C, the cod proteins begin to coagulate: the texture becomes rubbery, dry, and fibrous. It is irreversible. The only tolerated use of lukewarm water is the first 30-minute soak in the express method, and never above 40°C.

Error 4: Using a container that is too small

If the cod is not completely covered with water, the parts that stick out above desalt unevenly. The result is a piece of cod that is perfect on one side and excessively salty on the other. Always use a container where the water comfortably covers the pieces, at least 3-4 liters of water per kilogram of cod.

Error 5: Mixing thick and thin cuts

Cod flakes can be perfect in 12 hours, while a thick fillet needs 48 or more. If you desalt them together, you either remove the over-desalted (and bland) flakes or leave the fillet insufficiently desalted. Use separate containers for different thicknesses and monitor the times for each.

Error 6: Not drying the cod before cooking

After desalting, the cod is soaked with water. If you put it directly into a pan or hot oil without drying it, all that water is released at once: the temperature drops, the oil splatters, and the cod cooks in its own moisture instead of browning or confiting properly. Always dry thoroughly with kitchen paper on both sides before cooking.

Error 7: Adding salt to the desalting water

Some old recipes suggest adding a little salt to the water "to control the process." This is counterproductive: by increasing the salt concentration of the water, you reduce the osmotic gradient and the cod releases less salt. The desalting water should always be clean, unsalted water.

Before cooking: drying and salt level

Dry the fish well with absorbent kitchen paper before cooking. This step seems minor, but it is critical to achieve good texture, especially if you are grilling, baking, frying, or confiting the cod. Wet cod does not brown: it cooks in its own water.

Do not add salt directly to the cod before cooking. Desalted cod already contains the right amount of residual salt. If you add more, it is very likely that the dish will be too salty. You can season the sauce, broth, or garnish, but always taste first. A good trick: taste a small piece from the center of the thickest part just before cooking. If it needs more salt, you can add it to the final dish.

Ideal recipes according to the type of desalted cod

Each cut of desalted cod is best suited for certain preparations. Here's a quick reference:

• Thick fillets: bacalao al pil-pil, baked with potatoes, a la vizcaína, confit at low temperature. For these recipes, you need perfect desalting for 48-72 hours because the fillet is the absolute star.
• Medium fillets: cod with tomato, in green sauce, stews with legumes, omelets. Desalted cod ready to cook is perfect for these preparations.
• Flakes and shredded cod: cod croquettes, fritters, brandade, salads like esqueixada. Shredded cod comes ready for these recipes.
• Cheeks (kokotxas): in green sauce, al pil-pil or battered. They need careful desalting for 24-36 hours to avoid losing their characteristic gelatinous texture.
• Cod tripe: traditional Basque and Galician stews, grilled. Requires 36-48 hours of desalting and responds well to prolonged methods.

Is it better to buy already desalted cod?

Desalting at home gives you total control over the salt level and is part of the culinary experience of working with cod. But it's not always practical. If you don't have 24-48 hours in advance, if you don't have fridge space, or if you simply want convenience, buying already desalted cod is an excellent alternative.

At Bacalalo, we work with desalted cod ready to cook, with the exact salt level that a professional desalting would provide. The advantages are clear:

• Saves between 24 and 72 hours of planning and water changes.
• Professional salt level: comes perfectly seasoned, with no risk of being too much or too little.
• Keeps well in the fridge (2-3 days) or frozen (up to 3 months without loss of quality).

However, if you want to customize the salt level (for example, leave it a little saltier for a stew that requires it), desalting at home gives you that margin of control.

Frequently asked questions (FAQ)

Conclusion

Desalting cod correctly is as important as the quality of the piece itself. It's not complicated, but it requires planning, patience, and attention to a few details that make all the difference between an extraordinary dish and a disappointment.

The essential points to remember:

• Always in the fridge, between 4°C and 8°C, never at room temperature.
• Skin side up for balanced desalting.
• 3-4 liters of cold water per kilogram, with a rack at the bottom if possible.
• Change the water every 8 hours with the traditional method, every hour with the quick method.
• Always taste before cooking: it's the only foolproof method.
• Dry thoroughly before cooking to prevent it from releasing water into the oil.
• Time depends on thickness: from 12 hours for flakes to 72 hours for thick pieces.

If you prefer to save yourself the process and have cod ready to cook with the perfect salt level, at Bacalalo you will find desalted cod of the same quality we have worked with since 1990 at Mercat del Ninot, with shipping throughout the Peninsula.