The technique is wonderful, even in Western preparations, and solves many problems home cooks have with salmon, namely the spatter when searing, the potential for sticking to the pan, and the struggle to keep the fish moist and juicy inside while developing plenty of browned flavor or crisp skin.
To get an idea, I bought several whole salmon from Pike Place Market (including coho, sockeye and wild and farm-raised king). I salted 5-ounce fillets evenly with about 1 teaspoon of kosher salt per fillet, then left them on a paper towel-lined tray in the fridge overnight, uncovered. Then, I compared them to fresh fillets cut from the same fish and seasoned with the same amount of salt just before cooking. Each was cooked skin-side down with a little oil in identical skillets heated to maintain a 390-degree surface temperature. I cooked all the salmon as I normally would: skin-side down to an internal temperature of 100 degrees (or about medium-rare with a translucent center for salmon fillets), with a short stay on the second side for color.
Right from the start of cooking, there was a noticeable difference between the fresh fillets, whose excess moisture caused a large amount of spatter, and the dry-brined fillets, which seared with very little spatter. As the fresh fish cooked, globs of white protein started collecting at its edges, while the dry-brined salmon remained bright orange the entire time. Flipping the dry-brined fillets was also significantly easier than flipping the fresh, and the dry-brined fillets reached their target internal temperature about 20 percent faster, with better exterior browning and crisper skin.
By weighing the salmon fillets before and after their overnight rest, as well as before and after cooking, I could determine how much moisture was lost, and at what stage. As it turns out, every salmon fillet lost 8 to 11 percent of its weight in moisture. So what’s the difference?
With the dry-brined fillets, most of this moisture evaporates during storage; only a small amount comes out during cooking. With fresh, on the other hand, all that moisture is pushed into the pan during cooking, where it must then evaporate. This robs heat from the pan, explaining why fresh fillets take longer to cook and don’t brown or crisp as well. As that water is expressed from inside the fillets, proteins come along for the ride, coagulating in unsightly white blobs on the salmon’s surface. Excess protein-rich moisture in the pan is also the culprit behind sticking and excess splatter.
