Short answer: mushrooms have a lot of water in them and water puts holes in puff pastry.
Long answer: Puff pastry dough is just layers of filo dough with an oil (usually butter or canola oil) in between. You can make it yourself or buy puff pastry laminated in the factory. Filo dough is a very, very thin, dry dough that becomes extremely fragile when it's moisture-absorption abilities are overwhelmed - which is pretty easy to do. The oil between filo-dough layers in Puff Pastry prevent the layers from bonding together during the cooking process. The leavener (baking soda or powder, depending on your recipie) in filo dough releases gas that pushes the layers of filo dough apart, creating the puffing effect. If too much water is introduced to the filo dough before the dough layers have a chance to puff and cook, the filo dough isn't strong enough to contain the gas and it tears instead of puffing. This leaves mushy, doughy, ugly holes in your beautiful creation. Once the puff pastry is cooked, you can pour all sorts of moisture over the top and it won't hurt anything - which is why you pour the gravy over the top of beef wellington after it's cooked.
Recipie items like fresh mushrooms and spinach have very high moisture contents that cook out early in the process and will put holes in your puff pastry if they are cooked together. In order to get around this problem you can either use dried mushrooms or pre-cook the mushrooms before adding them to your recipe. The latter is usually preferable because of the texture and flavor of dried vs. fresh mushrooms, but sometimes it's not possible to use pre-cooked fresh mushrooms and dried ones are required.
Some delicious recipes that involve cooking with dried mushrooms include risotto, pasta dishes, soups, and stews. Dried mushrooms add a rich and earthy flavor to these dishes and can be rehydrated by soaking them in hot water before cooking.
Magic mushrooms are available dried and sometimes fresh. They are soft when wet and hard when dried.
It is fine to eat fresh magic mushrooms. Mushrooms are dried so they can be stored for much longer periods of time. It is extremely important to properly identify any mushroom before you ingest it.
they are dried and then eaten.
My clothes dried in what seems to be record time! These sun-dried mushrooms are delicious!
48 hours
Hydrating foods is to add moisture. Some dried foods must be rehydrated before they are used in certain recipes. Chiles are a good example. They are soaked before using them to make sauces or soups. Dried mushrooms are rehydrated before using them in spaghetti sauce. Some dried fruits are rehydrated before using them in baked goods.
They don't have to be dried for you to eat them, but people dry them because they conserve better in that way.
4 ounces dried equals 1 lb reconstituted.
To prevent pastry from sinking in a steak pie, ensure that the pastry is properly chilled before use, as warm pastry is more likely to shrink. Additionally, blind bake the pastry for a short time before adding the filling; this helps firm it up and creates a barrier against moisture. You can also use pie weights or dried beans during blind baking to keep the pastry from puffing up or shrinking. Finally, avoid overworking the dough, as this can develop gluten and lead to shrinkage.
high temperatures destroy the good stuff in magic mushrooms. You can find more out at magic-mushrooms.net
Oh, dude, you're asking about dried shrooms by weight? Well, generally, one gram of dried mushrooms is roughly equivalent to, like, 10-20 dried shrooms. But hey, who's counting, right? Just remember, it's all about the trip, man.