How to Defrost Cod: 5 Methods and Tricks to Avoid Ruining It

Why how you thaw cod matters

Cod is a fish with a unique muscle structure: its fibers are long, orderly, and held together by gelatin and the natural moisture of the tissue. When you freeze it, the water in those fibers turns into ice crystals. If you thaw too quickly or with heat, those crystals break the fibers, and the cod loses water, texture, and flavor.

The result of poor thawing is cod that releases white liquid when cooked, is dry inside, rubbery when bitten, and has a dull flavor. The opposite of what it should be: juicy, firm, and with that clean taste of the sea that characterizes premium Icelandic cod.

At Bacalalo, we have been working with cod since 1990 at the Mercat del Ninot in Barcelona. After more than 35 years of daily handling this product, we assure you that thawing is the step where most customers lose quality — and the easiest to do well with a little knowledge.

Method 1: In the refrigerator (the best)

Time: 12-24 hours | Quality: ★★★★★ | Difficulty: Minimal

This is the method we use whenever possible. Slow thawing in the cold maintains the cold chain, allows ice crystals to melt gradually without breaking the fibers, and preserves all the texture and flavor of the cod.

How to do it

1. Take the cod out of the freezer and place it in a deep dish or tray (to collect any liquid it releases)
2. Leave it in its original packaging or cover it with cling film to prevent it from drying out
3. Place it in the bottom of the refrigerator (the coldest area, usually around 4°C)
4. Wait 12 hours for thin pieces (1-2 cm fillets) or 24 hours for thick loins (3+ cm)
5. Check that it is completely thawed by pressing the center with your finger — there should be no hard spots

Professional tip

Place the cod on a rack inside the tray. This way, any liquid it releases falls to the bottom, and the cod doesn't sit in its own water, which can soften the surface texture.

Method 2: In cold water (the safe quick method)

Time: 1-3 hours | Quality: ★★★★☆ | Difficulty: Easy

When you haven't planned ahead but have a couple of hours, thawing in cold water is the best alternative. Water conducts heat 25 times faster than air, so the process is greatly accelerated without raising the fish's temperature.

How to do it

1. Place the cod in an airtight bag (ziplock type) if it's not already vacuum-packed. It is essential that the water does not directly touch the fish
2. Submerge the bag in a large bowl of cold tap water (never hot or lukewarm)
3. Change the water every 30 minutes to keep it cold
4. A thin fillet will be ready in 1 hour; a thick loin in 2-3 hours

Professional tip

Let the faucet drip slowly over the bowl. The constant flow of new cold water speeds up the process and keeps the temperature always below 5°C. This is the technique we use professionally when we need to thaw quickly without compromising quality.

Method 3: In the microwave (the emergency)

Time: 5-8 minutes | Quality: ★★★☆☆ | Difficulty: Requires attention

It's not the ideal method, but when dinner is in 30 minutes and the cod is still frozen, the microwave can save you. The key is to use the defrost function (not heating at maximum power) and monitor constantly.

How to do it

1. Remove any metallic or aluminum wrapping
2. Place the cod on a microwave-safe plate
3. Use the "defrost" function or set the power to 30% (never 100%)
4. Set intervals of 2 minutes
5. After each interval, turn the cod over and check the areas that are already soft
6. Remove the thawed parts so they don't start to cook while the center is still frozen

Professional tip

Place the cod on a pair of chopsticks or a small rack inside the plate. This elevates the fish and prevents it from cooking in its own liquid from below, which is what produces that rubbery texture typical of poorly done microwave thawing.

Important

Microwave-thawed cod should be cooked immediately. Do not store it in the refrigerator or refreeze it — areas that have started to cook are a fertile ground for bacteria if not consumed immediately.

Method 4: Cooking it without thawing

Time: 0 minutes waiting | Quality: ★★★★☆ | Difficulty: Medium

Many professional chefs cook cod directly from frozen, especially in the oven or in stews. It is a perfectly valid option that avoids all thawing risks.

When it works well

• In the oven: Place the frozen cod on a bed of vegetables and bake at 200°C. Add 10-15 extra minutes to the usual cooking time
• In stews and soups: Add the frozen cod directly to the hot broth or sauce. It will thaw and cook at the same time
• Grilled: Possible but requires technique — medium-low heat, more time and patience for the inside to thaw before the outside burns

When it DOES NOT work

• For breading: Ice prevents flour or breading from adhering properly
• For confiting: Ice water ruins the oil emulsion
• For recipes where you need to flake it: Ajoarriero, bacalao dorado, brandada — you need the cod thawed and manageable

Method 5: In salt water (salted cod)

Time: 24-48 hours | Quality: ★★★★★ | Difficulty: Easy

This method is specific for salted cod that you have frozen. The process combines thawing and desalting in one step, saving overall time.

How to do it

1. Place the frozen salted cod in a large bowl with plenty of cold water
2. Store it in the refrigerator (never at room temperature)
3. Change the water every 8-10 hours — at least 3 changes
4. In 24-36 hours the cod will be thawed and desalted at the same time
5. Taste a small piece to check the salt level before cooking

If you buy pre-desalted cod from Bacalalo, this method does not apply — our desalted cod comes ready to cook and only needs to be thawed with method 1 or 2.

5 mistakes that ruin your cod when thawing

1. Leaving it on the counter at room temperature: This is the most common and most dangerous mistake. The surface of the cod reaches bacterial proliferation temperature (between 8°C and 60°C) long before the center thaws. Result: health risk and uneven texture.
2. Submerging it in hot water: It seems logical but it's disastrous. Hot water cooks the surface while the center remains frozen. The result is cod with a rubbery and cooked outer layer, and a still-hard center.
3. Thawing and refreezing: Each freezing-thawing cycle breaks more fibers and loses more liquid. If you thaw cod and are not going to use it, cook it all and freeze the prepared dish — never refreeze the raw product.
4. Not drying the cod before cooking: No matter which method you use: before cooking, always dry the cod with kitchen paper. Surface moisture prevents browning in the pan and produces dangerous splatters in hot oil.
5. Thawing without protection in the refrigerator: If you leave the cod exposed in the refrigerator, the surface dries out and absorbs odors from other foods. Always cover it with film or keep it in its original packaging.

Professional tips for thawing cod

• Plan the night before: Take the cod out of the freezer before going to bed and leave it in the refrigerator. The next morning it will be perfect for cooking at midday or in the evening.
• Freeze in individual portions: If you buy cod in bulk, divide it into portions before freezing. This way you only thaw what you need without having to handle the whole block.
• The finger test: Cod is properly thawed when, by pressing the center with your finger, the flesh yields gently without a hard spot. If the outside is soft but the center resists, it needs more time.
• Internal temperature: If you have a kitchen thermometer, the cod should be between 0°C and 4°C at its center once thawed. Below 0°C it is still partially frozen; above 5°C bacterial proliferation may occur.
• The absorbent paper trick: Once thawed, wrap the cod in kitchen paper for 10 minutes before cooking. It absorbs surface moisture and concentrates the flavor. This is what we do at Bacalalo before preparing any recipe.
• Don't rush: Slow thawing is always better. If you can wait 24 hours, do it. Your cod will thank you with a firm, juicy texture and a clean flavor that no shortcut can match.

The quality of the cod you thaw also matters. A premium Icelandic cod from Bacalalo has a denser muscle structure with more natural gelatin, making it more resistant to the freezing-thawing process than lower-grade cod.

Frequently asked questions