That won’t wash: should you rinse your mushrooms?

6 hours ago 2

What’s the best way to prep and cook mushrooms? Should I wipe, wash or simply peel them?
Olivia, by email
“I could witter on about mushrooms all day,” says fungi fan Will Murray, which is good news, because Olivia’s question is somewhat contentious. The chef and co-founder of Fallow, Fowl and Roe, all in London, even grows his own shrooms, and advises his chefs to clean them “at least three times in bowls of cold water”, which brings us straight to the great mushroom washing debate, which has been rumbling on for years.

Writing in the Guardian in 2003, Heston Blumenthal called advice against washing mushrooms in water in case they become waterlogged “nonsense”. He cites Harold McGee, who tested this theory in his book The Curious Cook: “McGee weighed 252g fresh mushrooms, submerged them in water for five minutes, then removed them, blotted the surface moisture and reweighed them.” The result was 258g, which, as McGee noted, is a 16^th of a teaspoon of extra water per mushroom. “This was after five minutes of soaking, so five to 10 seconds of rinsing under running water is going to make no difference whatsoever.”

Not so fast, though, because Ben Rand, executive chef at Bubala in London, says a pastry brush (or the back of a knife) is the best tool to “knock off the dirt”, as does Conor Spacey, author of Wasted. Meanwhile, Claire Thomson, author of Mushroom, prefers a piece of dry kitchen towel to rub off any muck. So, clear as mud then.

Peeling mushrooms, however, isn’t necessary. But, Spacey says, “if the stalk is thick and woody, do peel the stalk area; and, if the mushrooms are older and sitting in the ‘never to return drawer’ in your fridge, throw them a lifeline and peel away the top layer with a small knife”.

When it comes to the actual cooking, meanwhile, there are so many directions Olivia could go, but Murray’s main tip would be to treat mushrooms like a piece of meat: “Everyone talks about the heat intensity required to cook a steak, but your pan should be just as hot when you cook mushrooms.” Rand would add “a slug of olive oil, then throw in the mushrooms with a generous knob of butter – that helps create a sauce with the mushroom juices and glazes them beautifully”. Garlic is, of course, a great chum of the mushroom, and Rand often skewers a clove on to a fork and uses that to give them a stir: “It imparts an impressive amount of garlic flavour without overwhelming the dish.”

Be patient, though, says Thomson: “You need to cook mushrooms until all the liquid comes out; you hear that sizzle and they start frying properly,” she says. She then likes to add onions, garlic, chipotle, tomato puree and beans to make a filling for quesadillas. If you have any oyster mushrooms knocking around, Murray recommends popping them in a patty: “Shred and roast them with salt, then add mushroom stock and a bit of tapioca starch.” Press into patties, coat in flour and double fry so they’re nice and crisp: “You then get what looks like a pulled beef patty, but made of mushrooms.” Just add lettuce and pickles.

Thomson’s latest “revelation”, however, is grating mushrooms (think button or chestnut) into a meatball mix: “You knock out some of the mince and add more plant points, and it also gives this incredible texture that’s tender but not too bouncy or firm.” Even her mushroom-hating daughter wolfs those down “with gusto”. High praise indeed.