I bought four pint-sized boxes of white mushrooms (in cardboard, wrapped in plastic) at Whole Foods about a week ago. I noticed towards the end of the third box that the mushrooms had gotten mushy (no pun), and were developing an ammonia-like odor, like a cheese, and I just now went to open the fourth box, and knew before I even opened it that they had turned - there was moisture on the bottom of the box (was this from the mushrooms turning, or did the moisture cause them to turn?) - one whiff, and I knew to throw the box away before even removing the plastic. The boxes were sitting out on my kitchen counter - never refrigerated.
Does anyone know what happened, and have some storage tips for organic white mushrooms? Whole Foods sells them in bulk, where you can fill your own plastic bag - maybe this is the best way to go, although the one time I did this, I thought the quality of the bulk mushrooms was slightly lesser than the boxed version (the bulk mushrooms were bigger, but also a bit "tougher," for lack of a better term, and with less taste).