mushrooms
The fruiting body of various fungi, prized for a savory, umami-rich flavor that deepens with cooking; sauteed, roasted, or simmered into sauces and soups. They're mostly water by weight, which is the single fact that governs how they cook -- crowd them in the pan and they steam instead of browning.
Buying guidance
Choose mushrooms that are dry and firm with a fresh earthy smell; reject anything slimy, in wet packaging, or with dark, sunken spots. Slightly open gills on cremini or portobello are normal, not a sign of spoilage -- a strong ammonia smell and collapsing, wet flesh are the real red flags. Cook them in a wide, uncrowded pan over high heat: mushrooms release a lot of water as they heat, and that water has to evaporate before any browning starts.
Substitutions
- Cremini for button, or the reverse -- nearly interchangeable by weight, cremini a bit deeper in flavor.
- Portobello -- much larger and meatier, better sliced thick as a standalone piece than diced into a sauce.
- Dried shiitake, rehydrated -- far more concentrated flavor; strain and save the soaking liquid, which carries a lot of the mushroom flavor itself.
Tips & common mistakes
Washing them is fine, but soaking them or rinsing well ahead of time adds moisture that speeds up sliminess -- wipe or rinse briefly right before cooking instead.
Storage
Move them out of sealed store packaging and into a paper bag once home -- plastic traps moisture against them and they turn slimy within days, while a paper bag lets that moisture escape. They're more perishable than firmer vegetables even under good conditions, and raw mushrooms turn watery and rubbery if frozen, though cooked ones freeze acceptably.