Mushrooms that you purchase at a store are grown on sterile manure, that is the “dirt” that is clinging to them. And while it isn’t unsafe for you to consume, it isn’t delicious. If you have ever had a mushroom dish marred by grit, you know that you do really want your shrooms nice and clean before you cook. Brushing can remove this dirt, if it is all loose, but more often than not, some bits may be more firmly attached, or are hiding in the gills. My general rule for grocery store mushrooms is to wash in water. The exception to this rule is any mushroom you purchase pre-sliced or chopped, in which case they are already clean and ready to eat.

Mushrooms you forage for yourself if that is a skill you possess (only safely please and be sure you triple check any foraged items before consumption) or wild mushrooms that you buy from a reputable forager at a farmer’s market or other source, will likely have somewhat less grit, and will also be less hardy. Likely, they will also be significantly more expensive, so this is where careful brushing is the way to go, to prevent any damage to the product.

It is important to remember that the reason some cooks are so anti-water in mushroom cleaning is that mushrooms are little sponges, so it is easy for them to absorb water, which will affect them in cooking. So, when using water to wash them, you don’t want to let them soak for long. Fill a large bowl with cold water, and have a clean, lint-free towel nearby. Add a few mushrooms to the water at a time, about as many as you can easily handle in your cupped hands, and swirl them around in the water to loosen any dirt — this should take maybe ten seconds, at the most. Then immediately remove them to the towel, patting them as dry as you can and laying them out (caps up) to finish air-drying before washing the next batch. Once they have all been washed in this way, examine the mushrooms to ensure you do not see any visible dirt. If you spot some stubborn bits, use a damp paper towel to wipe them off.

While they make all sorts of “mushroom brushes” that you can find at kitchen supply stores, my favorite brushes for mushrooms are in the hygiene aisle. Extra-soft toothbrushes and baby brushes are my favorite way to gently and effectively remove the dirt from mushrooms. Use the baby brush for larger surfaces, and the toothbrush to carefully remove dirt from the gills or any smaller cavities. I will often follow with a damp cloth, just to make sure they are extra clean.