Judy Rogers was a huge proponent of salting early - her Zuni Cafe roast chicken salted 2-3 days before cooking is a case in point - but in her cookbook, she says, “Fish is a different case; freshness is imperative. When I preseason fish, it is for a few hours at most.”
In Salt Fat Acid Heat, Samin Nosrat says, “Unlike meat, the delicate proteins of most fish will degrade when salted too early, yielding a tough, dry, or chewy result. A brief salting - about 15 min - is plenty to enhance flavor and maintain moisture in flaky fish. Inch-thick steaks of meatier fish, such as tuna and swordfish , can be salted up to 30 min ahead.”
