Wet mushrooms and John Torode

Firstly, apologies. This is shameless 'sleb piggy backing. Mr Torode only makes the most fleeting of appearances here, and then only by twitter. Secondly, this isn't nearly as funny as I hoped it'd be. Maybe I'm not on form today but this is quite a dry read (and that's pretty much the only gag herein).

John Torode did initiate this post because he scolded a Masterchef contestant for immersing mushrooms, claiming they soak up water 'like a sponge' and wash away flavour. I've always thought this was a piece of kitchen myth so tweeted John Torode and the Masterchef program:

@MasterChefUK @JohnTorode1 if mushrooms absorb water "like a sponge", why don't they swell up and burst when it rains?

He replied:

John Torode @JohnTorode1@NewRiverDining @MasterChefUK .. Because the top ok the underside absorbs the water, which doesn't get wet when it rains .

OK, so even allowing for some strangeness in his language, this still isn't a very satisfactory response. Rain bounces for a start and mushrooms sit in vegetation which gets wet with precipitation and dew. If mushrooms act like sponges wouldn't the moisture be wicked off anything that comes in contact with them? John didn't reply to my further replies with links to debunking websites but someone called @HelenWestern did suddenly launch herself at me "you're clearly no fungi to be with". I can only assume she's his internet minder.

Purists talk of using a stiff, dry brush or wiping with a damp cloth but I prefer to wash mushrooms as I've noticed sizeable pieces of soil (I hope it's soil) can get trapped inside the mushroom gills. Wiping will not remove these. Yes, it's easy to wipe buttons, chestnuts, ceps and portabello but what of delicate oyster, trompette de la mort or pied bleu? There's no way you can wipe the deeply pleached and perforated surface of a morel.

Sod that!

Mushrooms are 90% water anyway so will a little external dampness really make much of a difference to their flavour? Cooking them is about removing water.

McGee debunked this some time ago. As have several others. But I decided to do my own investigation. I do, so you don't have to. No mushrooms were hurt in this process. That's a lie. They all died and were eaten but at least they didn't die in vain. They perished in a perfectly delicious ham hock, rocket and vermouth sauce.

Massacre!

I weighed a supermarket pack of chestnut mushrooms. 324g. I had accounted for the weight of the plastic box.

I washed them. I would normally put them in a colander and give them a blast under a cold tap but this is the nuclear option.

Then I shook off the excess water and weighed them again in their original packing. They were still damp to the touch.

335g. They have taken on 11g of water, that's just over two teaspoonfuls. 11g represents an increase of mass of 3%. This is more than I would have expected but I seriously doubt this is enough to wash away the flavour of the mushrooms. There were about 20 mushrooms in the pack so that's about half a gram of water each. And certainly, much of that was surface water and so would evaporate on contact with a hot pan. A 3% take-up cannot be equated to a sponge. 

I think it's therefore safe to wash mushrooms. See, no jokes.