I just love this stuff ....
Alton Brown took his myth busting mushroom washing idea from Harold McGee's The Curious Cook
(page 182). Harold took some (23) mushrooms that weighed a total of 252 grams, soaked them for 5 minutes, blotted them dry and threw them back on the scales. They weighed 258 grams, so had absorbed a whopping 1/2 Tablespoon (or about 90 drops) of water.
- did they really absorb
that much water? Since I don't have a good digital scale (on my wish list) I can't test my theory ... but using some basic logic I can assume the problem with the weight gain was at least (major) in part significantly influenced by the methodology.
If you just run water over the mushroom caps and brush it off (the only part of the mushroom that actually comes into contact with the growing medium other than the base of the stem) they will not, in theory, absorb that much water. Why? Like any other "plant" mushrooms draw dutrition from the roots - so some moisture will be absorbed up from the base of the stems - in only 5 minutes this might rehydrate some of the stem but little would get to the caps. OK - mushrooms lack the waxy cuticle of plants - which allows them to rapidly "expire" moisture and absorb it from the air. The point where I think the majority of the weight gain was achieved was in the gills under
the caps. Due to their close radial proximity and arrangement - they are prime candidates to hold water by capillary action
- easily 1-3 drops per mushroom when "soaked".
Based on theory (again, I don't have the digital scales needed to test and prove my theory) - a quick wash of the mushroom tops under running water will not cause significant water absorption - soaking would probably increase it.
So - let's turn our attention to cooking these little gems .... can anyone name one method of cooking that 2 additional drops of water would make a difference? Surely wouldn't make a difference in batter dipped and fried, wouldn't be a factor when added to a pot of stew ... and when you toss them into a skillet to saute - the first thing that happens is that the moisture cooks out ...