# Is there a simple test to determine if a mushroom is eatable or poisonous? **URL:** \ **Category:** Factual Questions\ **Created:** [April 25, 2004, 4:47pm UTC](https://boards.straightdope.com/t/is-there-a-simple-test-to-determine-if-a-mushroom-is-eatable-or-poisonous/241925 "2004-04-25T16:47:42Z")\ **Posts on this page:** 4\ **Page:** 3
**Author:** ![CoatOfArms](https://avatars.discourse-cdn.com/v4/letter/c/c68b51/32.png) [@CoatOfArms](https://boards.straightdope.com/u/CoatOfArms)\ **Post date:** [April 26, 2004, 1:11am UTC](https://boards.straightdope.com/t/is-there-a-simple-test-to-determine-if-a-mushroom-is-eatable-or-poisonous/241925/41 "2004-04-26T01:11:22Z")
Damn. I’m getting hungry. Will spare my wife’s dog :rolleyes: I’ve heard if they are young, they are not dangerous. What is “young” and how do I define a species? ---
**Author:** ![clairobscur](https://avatars.discourse-cdn.com/v4/letter/c/839c29/32.png) [@clairobscur](https://boards.straightdope.com/u/clairobscur)\ **Post date:** [April 26, 2004, 1:12am UTC](https://boards.straightdope.com/t/is-there-a-simple-test-to-determine-if-a-mushroom-is-eatable-or-poisonous/241925/42 "2004-04-26T01:12:06Z")
By the way, concerning brightly colored mushrooms, the pictures are often deceiving, color-wise (including the one I linked too). Or so I felt while searching for on-line pictures of lactarius. (OK…I promise I won’t insist anymore about not relying on books/pictures) ---
**Author:** ![clairobscur](https://avatars.discourse-cdn.com/v4/letter/c/839c29/32.png) [@clairobscur](https://boards.straightdope.com/u/clairobscur)\ **Post date:** [April 26, 2004, 1:33am UTC](https://boards.straightdope.com/t/is-there-a-simple-test-to-determine-if-a-mushroom-is-eatable-or-poisonous/241925/43 "2004-04-26T01:33:52Z")
> [@CoatOfArms](#): > > Damn. I’m getting hungry. Will spare my wife’s dog :rolleyes: I’ve heard if they are young, they are not dangerous. What is “young” and how do I define a species? When _what_ is young, exactly? Mushrooms generally speaking? Nope. Being young doesn’t make them edible. Or have you been told that the particular specie growing by hundreds behind your house can be eaten when young? (“only edible when young” would be a statement which would make me not considering eating them). Mushrooms can grow very quickly. Over the course of some days. Some species can be much more tasty (not the same thing as “edible”, of course) when young, like the [parasol mushroom](http://www.bluewillowpages.com/mushroomexpert/macrolepiota_procera.html) that I eat. If you look at the pictures, the one on the top is a young (tasty) specimen. The picture just below depicts an old (less tasty) one. The differences are obvious, but different mushrooms have totally different shapes and grow very differently, so you can’t give general rules about how to tell apart a young and an old one. ---
**Author:** ![flight](https://avatars.discourse-cdn.com/v4/letter/f/bbce88/32.png) [@flight](https://boards.straightdope.com/u/flight)\ **Post date:** [April 26, 2004, 2:05am UTC](https://boards.straightdope.com/t/is-there-a-simple-test-to-determine-if-a-mushroom-is-eatable-or-poisonous/241925/44 "2004-04-26T02:05:57Z")
> [@Danalan](#): > > Any truth to the old saw about mushrooms requiring more calories to eat and digest than are provided by eating and digesting them? On a related note, does any foodstuff have a negative food value? > [@quiltguy154](#): > > It’s always been my understanding that celery requires more calories to digest than it actually provides, hence a perfect diet food[except for its sodium content] In brief, [no](http://boards.straightdope.com/sdmb/showthread.php?t=191724&highlight=celery+negative+calories) . I thought Cecil had addressed this himself, but I could not find the column. [Previous page](https://boards.straightdope.com/t/is-there-a-simple-test-to-determine-if-a-mushroom-is-eatable-or-poisonous/241925.md?page=2)