Washing mushrooms in flour water

[TicTac]

Perhaps you might pause to offer thought as to the nature of my inquiry.  In this case it is related to the absorption of water comparing farmed/store bought mushrooms vs. wild varieties. 

 

I am also not sure what you are washing off your (what I am assuming are store bought) mushrooms...

 

I barely brush mine and they have all sorts of tiny bits of dirt, etc.  Some even have worms (I save those for stock though, my wife gets creep-ed out at the thought, regardless the additional protein).  Regardless, it all gets annihilated once it hits the smoking hot pan.

[Lisa Shock]

I always submerge wild mushrooms in water. It's the only way check that there aren't worms inside. (well without mincing the mushroom) The worms always come out seeking air after a bit, if there are any. I have seen far too many infested wild mushrooms that looked ok on the outside to trust just brushing them off.

[Anna N]

Perhaps we could let everybody have their own way by reading the Michigan Mushroom Hunters Club's take on the subject:

 

Let’s face it, mushrooms can be dirty… especially after a good rain. While we love the flavor of wild mushrooms, few of us like to eat dirt and bugs along with them, at least if we can avoid it. So, the question is what is the best way to clean them? Well, there really is no best way; there is only that way in which you are most comfortable.

 

Some people believe that you should never put your mushrooms under or into water to remove debris and bugs because it will reduce the mushroom’s flavor. Others believe that the bugs or even the soil found on or in the mushrooms can affect flavor, palatability, and a person’s health. You will have to make up your own mind regarding such things but it is a good rule of thumb to use as little water as possible when cleaning your mushrooms. (Click for the full article.) My bolding. 

Click

 

 

Edited November 5, 2016 by Anna N (log)

[tomishungry]

Commercial mushrooms are grown in a substrate which contains sterilized manure. Any that I buy are going to take a nice long salt water bath and get thoroughly scrubbed down. A quick run through my salad spinner and everything's dry and clean. I haven't noticed any water absorption, and at least psychologically, the flavor's greatly enhanced. No BS! (couldn't resist).

 

Prep them the way you're comfortable with. I'm comfy with nice, clean mushrooms.

Edited November 6, 2016 by tomishungry
typo (log)

[liuzhou]

I had free time today. Actually I was busy, but working at home. I was also cooking mushrooms. So I experimented too.

 

I held back one button mushroom (unwashed) and weighed it. 24g. I then soaked it for 5 minutes and reweighed it after wiping off surface moisture with a kitchen towel. 25g. Then I kept going. I have no idea how much any variations are due to remaining surface moisture, but the differences are so small as to be negligible.

 

0 minutes  - 24g

5 minutes - 25g

10 minutes - 25g

30 minutes - 26g

1 hour - 28g

2 hours - 28g

3 hours - 28g

 

Then I got bored and ate it - raw. It tasted like a mushroom.

 

Given that washing the damn thing in the first place would only take seconds and probably result in no weight difference, I'm going to continue washing them.

I'll repeat this with other mushrooms (oyster, shiitake etc) when I have time.

Edited November 7, 2016 by liuzhou (log)

[jmacnaughtan]

I agree with Anna N.  Life is too short to argue about washing mushrooms.

 

However, I did see an interesting technique where girolles are (washed briefly and) cooked twice - the first time just in oil, to throw off the juice, and later in butter with seasoning, etc.  The juice is then used as the basis for a sauce.  It's in French, but the mushroom cooking starts at around the 3-minute mark.

 

 

I like the idea that liquid coming out of your mushrooms is not inherently a bad thing.

[gfron1]

Just chiming in to reiterate what was said above. As many of you know I make a living foraging. And I can say firsthand with countless examples, that an oyster mushroom that has spent a little time on the log in a number of rains becomes saturated through and through. So on that point @TicTac is 100% undeniably correct. However, a short amount of rain does not absorb. I've found many young mushrooms after a serious but unsustained rain, which while a bit slimy on top, are not saturated through.

[Baron d'Apcher]

As it pertains to flour, it should be specified that it applies to white button mushrooms rather than other cultivated/wild varieties.

While I do not know the exact science other than the prevention of oxidation, "cuire dans un blanc" (as opposed to "cuire à blanc" or "blind bake") is a French technique for cooking vegetables such as artichokes (and occasionally offal; sweetbreads I think) in which the liquid is supplemented with lemon juice to lower the pH (make it more acidic, keep the vegetable firm) and a starch (flour).  I believe that the addition of flour to the water makes the cooking liquid opaque and thus limits oxidation through light and any addition of fat (oil/butter/animal fat) limits oxidation through contact with the air.  But I could be convinced otherwise.

 

In Japanese cooking, raw suchi ice is often added to the cooking liquid of bamboo shoots to keep them light in color and to remove the bitterness, as with artichokes, though I have yet to supplement flour with rice.

 

This leaves me wondering if adding baking soda to my mushroom poaching liquid will have any affect...

 

Edited November 8, 2016 by Baron d'Apcher (log)

[jmacnaughtan]

1 hour ago, Baron d'Apcher said:

As it pertains to flour, it should be specified that it applies to white button mushrooms rather than other cultivated/wild varieties.

While I do not know the exact science other than the prevention of oxidation, "cuire dans un blanc" (as opposed to "cuire à blanc" or "blind bake") is a French technique for cooking vegetables such as artichokes (and occasionally offal; sweetbreads I think) in which the liquid is supplemented with lemon juice to lower the pH (make it more alkaline, keep the vegetable firm) and a starch (flour).  I believe that the addition of flour to the water makes the cooking liquid opaque and thus limits oxidation through light and any addition of fat (oil/butter/animal fat) limits oxidation through contact with the air.  But I could be convinced otherwise.

 

In Japanese cooking, raw suchi ice is often added to the cooking liquid of bamboo shoots to keep them light in color and to remove the bitterness, as with artichokes, though I have yet to supplement flour with rice.

 

This leaves me wondering if adding baking soda to my mushroom poaching liquid will have any affect...

 

 

Cooking with flour is a technique I've heard of, but I've never actually seen done.  I get the feeling that it's been replaced by cooking in a small quantity of water with butter added.

 

There's a recipe in one of my Japanese cookbooks that calls for small turnips to be cooked in rice washing water, presumably to ensure they stay white.  I imagine it must be to do with the starch.

 

Why would you add baking soda, though?  If anything, that should act more as a tenderiser.

[Baron d'Apcher]

1 hour ago, jmacnaughtan said:

Why would you add baking soda, though?  If anything, that should act more as a tenderiser.

 

I am curious as to whether alkaline water has any effect.  Any chemists in the crowd?

[gfweb]

My suspicion is that all of this technique is based on wrong assumptions.

 

IIRC chitin is more soluble in acid than alkaline so baking soda might stabilize the mushroom structure.  But that's not taking into account the effect of heat that is added. Experiments are called-for.

 

 

 

 

[chefmd]

4 hours ago, Baron d'Apcher said:

As it pertains to flour, it should be specified that it applies to white button mushrooms rather than other cultivated/wild varieties.

While I do not know the exact science other than the prevention of oxidation, "cuire dans un blanc" (as opposed to "cuire à blanc" or "blind bake") is a French technique for cooking vegetables such as artichokes (and occasionally offal; sweetbreads I think) in which the liquid is supplemented with lemon juice to lower the pH (make it more alkaline, keep the vegetable firm) and a starch (flour).  I believe that the addition of flour to the water makes the cooking liquid opaque and thus limits oxidation through light and any addition of fat (oil/butter/animal fat) limits oxidation through contact with the air.  But I could be convinced otherwise.

 

You mean adding lemon juice to lower the pH and make cooking liquid more acidic?

[TicTac]

5 hours ago, gfron1 said:

Just chiming in to reiterate what was said above. As many of you know I make a living foraging. And I can say firsthand with countless examples, that an oyster mushroom that has spent a little time on the log in a number of rains becomes saturated through and through. So on that point @TicTac is 100% undeniably correct. However, a short amount of rain does not absorb. I've found many young mushrooms after a serious but unsustained rain, which while a bit slimy on top, are not saturated through.

 

I have found (and it may be unique to this variety which is extremely thick fleshed for an oyster) that even one good rainfall will saturate the exposed ones.  The nice thing is with the Elm Oysters is they only grow on trees, which makes drying time that much faster.

 

At the end of the day, 9/10 times my desired preparation of a mushroom will entail high heat searing with salt to remove water content and concentrate flavours.  Thus I choose to introduce as little water to the beasts as possible.  Every chef I have worked with and known would never expose their prized fungi to water.  Any tiny bit of dirt that my brush might miss gets incinerated by the heat and turns into roughage, and who cant use more roughage...!

 

 

[Baron d'Apcher]

1 hour ago, chefmd said:

You mean adding lemon juice to lower the pH and make cooking liquid more acidic?

Correct.  I was reading varying articles in French on lemon juice inside and outside the body and got my wires crossed.  I corrected the previous post.

 

Alkaline water preserves color in green vegetables (but makes them more fragile) and I wonder if it helps preserve the white color of button mushrooms.  Probably not, or else there would be tips for it somewhere on the interwebs.  

[dcarch]

36 minutes ago, TicTac said:

 

I have found (and it may be unique to this variety which is extremely thick fleshed for an oyster) that even one good rainfall will saturate the exposed ones.  --------------

 

 

Not trying to disagree. I don't have the scientific information as to what makes fungi grow. Just being curious.

But perhaps the rain water is absorbed up through the  stem, and not down from the cap?

I would imagine that in the structure of a mushroom, water can only go in one direction, from the stem up to grow bigger.

 

dcarch

 

 

[gfweb]

12 minutes ago, dcarch said:

 

Not trying to disagree. I don't have the scientific information as to what makes fungi grow. Just being curious.

But perhaps the rain water is absorbed up through the  stem, and not down from the cap?

I would imagine that in the structure of a mushroom, water can only go in one direction, from the stem up to grow bigger.

 

dcarch

 

 

 

I think you have a point. After all, one puts flowers in a vase of water stems down.

[TicTac]

It might come from both the stem and via the cap - I have noted soaked stems as well in the past.

 

But I have also noted mushrooms growing seemingly hanging under (attached to) a fallen tree totally protected by the rain, and dry when other exposed ones are soaked.

 

 

 

 

[liuzhou]

On 07/11/2016 at 8:55 PM, liuzhou said:

I had free time today. Actually I was busy, but working at home. I was also cooking mushrooms. So I experimented too.

 

I held back one button mushroom (unwashed) and weighed it. 24g. I then soaked it for 5 minutes and reweighed it after wiping off surface moisture with a kitchen towel. 25g. Then I kept going. I have no idea how much any variations are due to remaining surface moisture, but the differences are so small as to be negligible.

 

0 minutes  - 24g

5 minutes - 25g

10 minutes - 25g

30 minutes - 26g

1 hour - 28g

2 hours - 28g

3 hours - 28g

 

Then I got bored and ate it - raw. It tasted like a mushroom.

 

Given that washing the damn thing in the first place would only take seconds and probably result in no weight difference, I'm going to continue washing them.

I'll repeat this with other mushrooms (oyster, shiitake etc) when I have time.

 

 

Well, I got round to doing some. I bought some straw mushrooms (Volvariella volvacea), some shiitake and some eryngii or king oyster mushrooms (Pleurotus eryngii). One of each was weighed unwashed. (Weight in grams). They were then washed under running water for between 15 and 30 seconds, as much surface water as possible removed and then re-weighed.

 

Straw mushroom (unwashed)

 

Shiitake (unwashed)

 

Eyrngii (unwashed)

 

They were then left to soak for 5, 15, 30 minutes, then 1, 2, 3 hours, and finally for 21 hours. They were completely submerged. At those intervals, again as much surface water as possible was removed and they were re-weighed.

 

Here are the results:

 

Straw Mushroom

 

This was a very fresh, tightly closed example. After washing the weight hadn't changed indicating zero water absorption. As the soaking time passed, it slowly increased in weight until the 21 hours were up, by which time the veil was opening and the mushroom had started to auto-deliquesce, losing water into the soaking medium.

 

Shiitake Mushroom

 

The shiitake was most prone to absorption, presumably through the gills (it was the only open gilled sample). The open gills also meant that it was more difficult to be sure that all surface water had been removed. This may have a bearing on the results

 

Eryngii Mushroom

 

This was the most "solid" sample.

 

What I notice is that, in all three cases, there is a steady, if slight, increase in the absorption untiol betweeh 2 and 3 hours when, for some reason, it slows down.

 

Other than that, and what relevance it has is lost on me, the only real conclusion I can draw is that a brief wash makes a negligible difference, if any. I mean who in their right mind soaks fresh mushrooms, anyway.

 

Apologies for any errors, especially in the maths. I'm a linguist; maths scares me!

 

I'm off to make some mushroom soup.