In most cases, we—food writers, cookbook authors, and anyone else trying to teach people how to cook—encourage people to add salt at the beginning of the cooking process. This gives the salt time to work its way into various ingredients, seasoning them all over rather than on the surface. But with mushrooms, it’s the exact opposite of what cooks should do.
Mushrooms are between 80 and 90 percent water, so adding salt at the start of cooking can cause them to release this liquid, which prevents browning. (While we’re talking about humidity, it’s mostly a myth that you shouldn’t rinse or soak mushrooms in water. In reality, most varieties – except for those like morels, lion’s mane and matsutake mushrooms – absorb a tiny amount of water.)
Additionally, early salting can have a negative impact on texture. “To preserve the texture of the mushrooms, wait to add salt until they begin to brown in the pan,” cookbook author Samin Nosrat wrote in “Salt Fat Acid Heat.”
Here’s a simple explanation of how to cook mushrooms – on the stovetop or roasted in the oven: Wash them to remove any surface dirt; cut or slice them, as you wish; add them to a hot, preheated pan, with or without oil (this is not necessary) and being careful not to crowd them too much (although a little is good) as this can prevent moisture from ‘they free to evaporate; add salt only once the mushrooms have started to brown; continue with the rest of the recipe.
