Matstuake being washed in a bucket in Yunnan, China

Grit is a terrible thing to have in a mushroom dish — and so the world over mushrooms are cleaned by dunking them in water. In Lithuania, I cook with friends who soak the caps of Leccinum and Bolete species in lightly salted water before frying them — a process that significantly improves their flavor. Mushrooms are designed to be rained on. You will find mushroom caps to be pretty impervious to water. Gills are coated with a wax-like substance and also resist absorbing water. My general practice is to run the caps of large mushrooms under the kitchen tap. Smaller mushrooms I dunk in a bowl of water — sometimes lightly salted. I follow this washing or dunking practice with mushrooms I buy in the store as well as those I find in the wild.

Portobello mushrooms dry out in the market. I always soak them in a bowl of lightly salted water for an hour before cooking with them.

If, after washing mushrooms in water you find they are too soggy for the use you intend for them, then them is dry out in the kitchen on a towel for a few hours. Mushrooms are designed to withstand rain — and they are designed to dry out a little between storms so you will find that they quickly lose excess water. Where I live ,chanterelles are often soggy (and muddy) when picked. I wash them in water and let them dry for a couple days in my kitchen before cooking with them.

Are there exceptions? Are there some instances where dunking the mushroom is a bad idea? Of course there are. There is a delicate termite mushroom in Yunnan that, when cooked its most delicate way, is brushed rather than washed with water. After brushing, the mushroom is thinly sliced, and put aside. The wok is then heated until any residual oils have burned off. The wok is then set aside to cool a little. When cooler, but still hot, it is sprinkled with salt and the mushrooms are rapidly braised. If the pan is not cleaned properly by burning off the oils, the sweet taste of the mushroom will be overpowered by the oil. In Italy, perfect small caps porcini, Boletus edulis and closely related mushrooms, are thinly sliced and served raw as a salad. Young boletus caps intended for salad can be quickly washed with water, but they should be thoroughly dry before being dressed with salt and olive oil. You will find that the pores of young boletus caps do not absorb much water, while the pores of old ones do. I don’t soak old boletus caps in water, instead I trim off dirt that is stuck to the pores.