Mushrooms

Why

Fresh mushrooms are mostly water, button mushrooms about 90 %, and they release it into the pan as they heat; so they first stew in their own juice and brown only once the water has evaporated. An overcrowded pan or fat that isn't hot enough only prolongs this stage, and salt added at the start draws the water out sooner; mushrooms taken off the heat before the juice has evaporated end up grey and rubbery. Wild mushrooms are not eaten raw, even edible species often cause digestive upsets when raw, and dishes made from them should therefore be cooked for at least 15 minutes. The widespread claim that mushroom dishes must never be reheated is only half true: problems come mainly from badly stored mushrooms and dishes, whereas a dish cooled quickly and kept briefly in the fridge can be reheated once. Only gather and eat mushrooms you can identify with certainty; phone apps often cannot identify a species unambiguously.

How to do it

• Clean mushrooms with a knife or brush, rinse dirty ones only briefly and dry them at once; never leave them sitting in water.
• If you want them browned, heat a pan with fat and fry them in batches in a single layer; for a sauce or soup, softening them is enough.
• Let fried mushrooms evaporate their juice and brown; you can salt them at any point, salt at the start only speeds up the release of water.
• Never eat wild mushrooms raw, and cook dishes made from them for at least 15 minutes.
• Cool leftover mushroom dishes quickly, refrigerate them (ideally at 2–4 °C), use them up soon and reheat only once, until piping hot throughout, to at least 74 °C in the centre.
• Gather and cook only mushrooms you know with certainty; have uncertain finds checked at a mushroom advice centre, not by an app.

If it goes wrong

Leave watery mushrooms in the pan uncovered until the juice has evaporated, then brown them; you can also pour the juice off into a sauce. To get rid of grit from dried mushrooms, strain the soaking water through a fine sieve or a paper filter. If nausea, vomiting or diarrhoea appear after a mushroom meal, call a doctor, the emergency services or a poison information centre, even if the symptoms start many hours after eating – the most dangerous poisonings often have a late onset. Keep any leftover mushrooms and food for identification.