Brine White Fish: Cod, Halibut Salt Ratio and Time

Brine white fish such as cod and halibut for 15 minutes in a 4.75% salt brine. For 1 lb (0.45 kg) of fillets that is 22.5 g (0.79 oz) of salt in 0.5 quart (0.47 L) of water, in the refrigerator. A 7.6% brine takes 10 minutes.

White fish is lean, and the brine is short. The times apply to fillets or steaks up to 1 inch (2.5 cm) thick.

Brine strength

The calculator has two strengths for white fish. Each is a percentage of the water's weight, so 4.75% means 4.75 g of salt per 100 g of water.

• Standard, 4.75% is the default, for 15 minutes. It comes from America's Test Kitchen's fish brine: 5 tablespoons of salt in 2 quarts of water, 15 minutes, for up to six 1-inch-thick steaks or fillets. ATK tested it on tuna, salmon, swordfish and halibut, and says it worked regardless of species.
• Quick, 7.6% is for 10 minutes. ATK's quick brine is 1 tablespoon of salt per cup of water, tested on white fish such as cod and haddock and on salmon.

Both ATK figures have a catch. ATK labels the standard brine 6 percent and the quick brine 9 percent, but it writes "salt" with no type. Read as table salt at 6 g per teaspoon, 5 tablespoons in 2 quarts is 4.75 percent and 1 tablespoon per cup is 7.6 percent. The calculator uses the figure that follows from the volumes, which is the lower one.

Great British Chefs gives 100 g of table salt per liter of water, 10 percent, for 15 to 30 minutes. The calculator uses the lower percentage and the shorter time. Recipes differ because they differ on salt type, on whether the percentage is by weight or by volume, and on thickness.

Because the salt type is not named, the volume you measure matters. Table salt, Morton kosher and Diamond Crystal weigh different amounts per spoonful. The kosher salt versus table salt guide explains the difference, and the brine percentages explained guide shows how to read a percentage.

Salt and time by weight

Weigh the fillets before brining, without the brine. The table is for the standard strength and uses the default of 0.5 quart of water per pound.

For the quick brine:

Weighing the salt is the reliable way to measure. The volume columns help when you have no scale.

How to brine white fish

1. Weigh the fish and the salt. Use the table above, or the calculator for your weight.
2. Dissolve the salt in the water until no crystals remain.
3. Chill the brine. Fish and brine must stay at 40°F (4°C) or below.
4. Submerge the fillets completely in a food-safe container and put it in the refrigerator. USDA FSIS says the refrigerator should be at 40°F or below.
5. Set a timer for 15 minutes at the standard strength or 10 minutes at the quick strength.
6. Drain and pat dry. ATK found that a wet brine did not prevent browning as long as the fish was patted dry before cooking.
7. Cook. FoodSafety.gov gives 145°F (63°C) for fish, or cook until the flesh is no longer translucent and separates easily with a fork. Season lightly, since the fish already carries salt.

What the brine does

ATK says a brine partly breaks down muscle fibers in fish and forms a gel that holds water, which helps keep the fish from drying out. It also says fish brines faster than meat because its muscle fibers are much shorter, which is why the times are minutes.

The quick brine has a second purpose. ATK found that it reduces the white albumin that coagulates on the surface of fish during cooking, which improves appearance. It reported a dramatic improvement for both white fish and salmon. The soak also seasons the outside of the fish, so ATK says a separate salting beforehand is not needed.

Sitka Seafood Market, a retailer, says lean white fish such as cod and rockfish benefit greatly from a quick dry brine of 1 tablespoon of salt and 1/2 teaspoon of sugar per fillet, rested 10 minutes. That is a single retailer source with sugar added, and the calculator does not use it.

What happens if you go over the time

The calculator's maximums are the times America's Test Kitchen gives: 15 minutes at the standard strength and 10 minutes at the quick strength. ATK does not state a longer time or a reason for the limit, so this guide does not either. Sitka Seafood Market, a retailer guide, gives 12 minutes for the same volumes as the 15 minute brine, which is the more conservative figure, and The Splendid Table gives 1 1/2 hours. The warning above lists both.

Great British Chefs says the flesh will begin to cure if fish stays in its own 10 percent brine longer than its 15 to 30 minutes. That warning is about its stronger brine, so it is not the reason for the limits here and not applied to these strengths.

Long salt cures and smoking brines, which run hours to overnight and often include sugar, are curing steps. This calculator does not cover them and gives no amounts for them. Curing salt and nitrite are also outside it.

The can you over-brine meat guide gives the maximum brine times for several foods and the saltiness limit behind them.

Safety

The brine food safety guide covers refrigeration, brine reuse, time limits and what the calculator does not cover. The seafood brine time chart lists white fish with the other seafood. Two other fish have their own guides: brining salmon and brining trout.

Practical problems

The fish is too salty. Check the time against the 15 or 10 minute limit, then check the salt type. A recipe written for table salt, used with the same volume of Diamond Crystal, makes a weaker brine.

The fillets are thicker than 1 inch (2.5 cm). The sources give their times for fillets or steaks up to 1 inch thick. The calculator has no separate time for thicker pieces.

The fillets are thin. The calculator has no separate shorter time for thin fillets, and the limits above still apply.

White albumin still shows. ATK says the brine reduces albumin. It does not say it removes all of it.

The fish is not covered. Use more water and enter the new amount in the calculator so the salt matches it.