Brine Trout: Salt Ratio and Time

Brine trout fillets for 15 minutes in a 4.75% salt brine, which is 22.5 g (0.79 oz) of salt in 0.5 quart (0.47 L) of water for 1 lb (0.45 kg) of fish. Keep the container in the refrigerator.

One fact first: none of the sources behind these fish brines names trout. The numbers here come from general fish brines for steaks and fillets, and this guide says where that matters.

What the numbers rest on

America's Test Kitchen tested its fish brine on tuna, salmon, swordfish and halibut, and says it worked no matter the species. Great British Chefs gives a brine for fish without naming trout. The calculator applies those general brines to trout fillets because no trout-specific brine from a tested source was found.

That makes the trout numbers less specific than, for example, the salmon brine, where a source names the fish. If you have a trout recipe you trust, compare its percentage and time against the strengths below. The brine percentages explained guide shows how to convert a recipe's tablespoons into a percentage.

The trout brines in Wyoming Game and Fish and Maine Inland Fisheries and Wildlife recipes run 2 to 12 hours and come before smoking. They are left out. Long salt cures and smoking brines, which run hours to overnight and often include sugar, are curing steps, and this calculator does not cover them or give amounts for them. Curing salt and nitrite are also outside it.

Brine strength

The calculator has two strengths. 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 ATK's fish brine: 5 tablespoons of salt in 2 quarts of water for up to six 1-inch-thick steaks or fillets. ATK labels this 6 percent, but 5 tablespoons in 2 quarts, read as table salt at 6 g per teaspoon, is 90 g in 1,893 g of water, or 4.75 percent. The calculator uses the figure that follows from the volumes.
• Quick, 7.6% is for 10 minutes. ATK's quick brine for prettier fish is 1 tablespoon of salt per cup of water, which ATK calls a 9 percent solution. Read as table salt, 18 g in 237 g of water is 7.6 percent. ATK tested it on white fish such as cod and haddock and on salmon.

ATK writes "salt" with no type for both brines. Great British Chefs gives 100 g of table salt per liter of water, which is 10 percent, for 15 to 30 minutes for fish in general. The calculator uses the lower percentage and the shorter time.

Salt type changes the volume you measure. The same spoonful of table salt, Morton kosher and Diamond Crystal weighs a different amount. The kosher salt versus table salt guide covers why, and weighing the salt avoids the problem.

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 of fish. The times apply to fillets up to 1 inch (2.5 cm) thick.

For the quick brine:

How to brine trout

1. Weigh the trout 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. The 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.

Why the time is short

ATK says a fish brine partly breaks down muscle fibers 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. That is the reason these times are minutes.

The calculator's maximums are the times America's Test Kitchen gives for its brines: 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.

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 trout beside the other fish and shrimp. The can you over-brine meat guide gives the maximum brine times for several foods and the saltiness limit behind them. Brining white fish uses the same general fish brines.

Practical problems

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

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

Whole trout, or a smoked result. The calculator covers fillets brined for texture and moisture before cooking. Its values do not cover whole fish, and smoking brines are outside it.

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