Every time someone says “you shouldn’t wash a mushroom” a scientist silently laughs somewhere. No, really, this is a myth that most probably came to life because of the mushroom appearances. It looks like a sponge hence it behaves like a sponge, i.e. it soaks up liquid. Logical, but this conventional wisdom supposedly popped up in the renowned culinary masterpiece – Larousse Gastronomique, where the French chef Prosper Montagne warned his readers from washing shrooms. He said it was going to affect their flavor. But this was 1937 and mushrooms’ nature was perceived quite straightforward – as a thirsty sponge. Since that year people only scraped mushrooms in their kitchens or wiped off the dirt with white towels.
But then came Harold McGee – an inspiration of many contemporary cooks and a culinary mastermind – with scales and a calculator. We weighed 250 gr of mushrooms, before plunging them into the water and after. He kept them submerged for 5 minutes flat. During this time they soaked up only 6 grams of liquid. That’s 3 teaspoons per kilogram, which means, in turn, an additional 10-15 seconds of frying. Hardly enough to ruin a recipe.
It’s also hard to imagine situation when you really need to soak your mushrooms in the water. A quick rinse will probably do the trick. Or a salad spinner. Yes, it can be used in so many ways, but that’s another story.
And don’t be afraid of the dirt that might cling hiding under the cap. If you get your shrooms from the supermarket then it’s most likely they are of cultivated variety, which means it’s peat moss growing on them, not dirt, and it’s all pasteurized. Honestly, such mushrooms can even be eaten raw, at least they are absolutely fine to cook with as they are. It’s wild mushrooms that need more thorough cleaning.
To sum up. Don’t be afraid of washing your shrooms, water will be even barely noticed, and of course they won’t ruin your dish. Also, don’t forget that mushrooms are made of over 80% water themselves. With that in mind, go to your kitchen and make a nice spaghetti with portobello and tomato sauce which is better ‘googled’ as a ‘quick mushroom ragu’. Every recipe sounds a bit tastier when it has a French word in it. Bon appétit.