How to Pan-Fry Mushrooms Until Brown and Crispy

To brown and crisp mushrooms in a pan, use high heat and an uncrowded pan; arrange mushroom slices in a single layer without letting them touch. Mushrooms crowded into a pan steam, release their liquid early, and become boiled in texture instead of browned. The second key point is when to salt them: salting mushrooms draws water out of their cells immediately, so add salt only after browning is complete.

Why shouldn’t the pan be crowded?
Mushrooms have a porous structure made up mostly of water. When they are crowded in a pan, steam gets trapped between them; instead of browning their surfaces, the steam cooks them and the liquid they release collects on the bottom of the pan. For this reason, fry 1 kg of mushrooms in 2 or 3 batches, depending on the size of the pan, rather than all at once; reheat the pan between batches.

What heat and timing give the right result?
Let mushrooms sit untouched over medium-high heat for about 3–4 minutes; this is needed for the underside to brown. Stirring often makes the mushrooms steam rather than brown because each stir lowers the pan temperature. Once the underside is dark golden, turn the mushrooms once and leave them for another 2–3 minutes to brown the other side.

When should oil and salt be added?
Add a mixture of butter and olive oil to the heated, empty pan just before the mushrooms; the milk solids in the butter let it contribute flavor without burning over high heat. Do not add salt before browning is complete. Early salting makes the mushroom cell walls release water and the pan becomes wet immediately; sprinkle in the salt just before removing the mushrooms from the pan.

Common mistakes
The most common mistake is putting mushrooms in the pan immediately after washing them without drying them; water droplets left on the surface lower the pan temperature and create the same steaming effect. Wipe mushrooms with a damp cloth before washing. The second mistake is adding mushrooms before the pan is hot enough; mushrooms put in a cold pan release their liquid while waiting for the pan to heat and will not brown afterward.

How does the technique vary by mushroom type?
Thin mushrooms such as white button and cremini are suited to the timing above. However, thinner, more porous varieties such as oyster mushrooms brown more quickly, in about 2 minutes, because of their large surface area and faster evaporation. Thick slices such as king mushrooms (portobello), cut to about the size of an orange, take longer, about 5–6 minutes; cook these slices uncovered for the first few minutes, then cover the pan so the inside cooks as well.

Can frozen mushrooms be fried?
Frozen mushrooms release much more liquid than fresh mushrooms when placed in the pan because their cell structure is damaged during freezing; therefore, thaw and drain them first, then dry them as much as possible. Mushrooms placed directly into the pan while frozen almost always turn out as if boiled. Let thawed mushrooms stay in the pan a little longer than fresh ones; use the first 1–2 minutes only to evaporate the released liquid, and begin browning only after the water is gone. A practical option for people short on time is to partially thaw frozen mushrooms on the microwave's defrost setting and cook them right away; this shortens the time they need to stay in the pan. If you have time, thaw them in a strainer in the refrigerator.