Dried mushrooms need time in water to become supple enough for the dish. Use a known edible product and follow its packet, since thin porcini slices and thick shiitake caps soften at different rates. Soaking prepares mushrooms for cooking; it does not replace cooking.
Step by step
Inspect and rinse the dried mushrooms
Use mushrooms sold as food from a reliable supplier. Discard damaged or suspect pieces and rinse away loose debris under running water. Place the amount needed in a clean bowl.
Cover with the specified water
Add water at the temperature recommended on the packet. A small clean plate can keep floating pieces submerged. Soak only until the mushrooms are pliable enough to prepare, checking thicker centres.
Lift out and check for grit
Lift mushrooms from the liquid rather than pouring sediment back over them. Rinse away any remaining grit and remove tough stems where needed. Slice or chop for the recipe.
Cook and use the liquid only when suitable
Cook the mushrooms thoroughly as directed. If the packet and recipe use the soaking liquid, pour it carefully through a fine filter and leave sediment behind, then cook it in the dish. Discard it where the product instructs you to.
Long soaking needs refrigeration
Keep any soak lasting more than 2 hours in the refrigerator; for overnight soaking, refrigerate from the start. Use soaked mushrooms promptly. Discard mushrooms that become slimy or smell abnormal, and do not rely on boiling to rescue mushrooms left soaking too long in a warm kitchen.
