When developing the method for her new weeknight steak stroganoff dinner, senior food editor Anna Stockwell dutifully salted her mushrooms after sautéing them for several minutes. You see, unlike with most ingredients, which we like to season early and often, the prevailing wisdom regarding mushroom recipes is that salting the fungi early will cause the water held within the mushroom's spongelike texture to leak out and prohibit browning.
When I was chatting with Anna about her recipe, however, I found myself wondering if that theory is accurate or just folklore? We decided a side-by-side mushroom-cooking test was in order.
We set up next to each other in the Test Kitchen with identical cast-iron pans placed over high heat, each slicked with 2 tablespoons of vegetable oil. At the same time, we each piled an equal combo of chopped cremini and torn maitake mushrooms into the hot pans, but here is where we diverged: immediately, I dusted my mushrooms with 1/2 teaspoon kosher salt. We stood side-by-side, occasionally tossing mushrooms around with a wooden spoon and shaking the pans as necessary. At seven minutes, Anna's mushrooms were evenly browned and they had considerably reduced in size. She sprinkled the pan with 1/2 teaspoon of kosher salt, gave the mushrooms one last toss and then removed them from the stove.
Meanwhile, my mushrooms were still going. Although we'd noticed very little liquid leaching out, and my mushrooms had begun to brown at the same time as Anna's, my mushrooms were taking longer to turn soft and tender. After 10 minutes they were fully cooked, but they still hadn't reduced as much as Anna's mushrooms had—which translated into them having a less concentrated flavor. In addition, my mushrooms—particularly the maitake—had a tougher texture than Anna's.
The bottom line: Although salting the mushrooms at the beginning of cooking does not always cause them to release much liquid, it does make them cook more slowly and gives them a less desirable texture. Salting mushrooms near the end of cooking, however, results in more concentrated flavor and an ideal meaty tenderness. So, in this case at least, the old wisdom still applies: sauté mushrooms first, season them second, and then (if you're Anna) coat them in a cream sauce and spoon over buttered noodles and medium-rare steak to finish.
