Geoff Dann is a mushroom foraging instructor and these are his tips on how to pick mushrooms for dinner without picking up a deadly poison.
1. Buy a good book on mushrooms, rather than on foraging
Do not use a book about mushroom foraging as a tool for identifying what you find, because nearly everything you find won't be in it.
There are well over 3000 species in the UK. Your mushroom foraging book will cover less than 100 of them.
2. Learn how to recognise the deadly species and groups before you go
The worst of these are the Deathcap (Amanita phalloides), Destroying Angel (A. virosa), Funeral Bell (Galerina marginata), Fool's Funnel (Clitocybe rivulosa), and the whole genera of Cortinarius (webcaps), Inocybe (fibrecaps) and Lepiota (dapperlings).
3. Make a hitlist of about ten common species you think you can identify
Choose ones that aren't easy to mix up with anything poisonous. It should include Shaggy Inkcaps, Giant puffballs, Beefsteak Fungus, Hedgehog Fungus, Cauliflower Fungus, Penny Buns, Bay Boletes and Brown Birch Boletes.
4. Do not eat anything unless you are absolutely certain of its identity
Mushrooms don't kill; wishful thinking and stupidity does.
Do not be tempted into believing you've found what you're looking for, just because it looks sort of similar, or because you can't find anything in your book that looks more like it.
Unless it matches the description perfectly in every way, do not eat it.
5. Make sure you check whether there are any special cooking requirements
Some fungi are listed as edible are toxic raw. Some require long cooking to break down their toxins and make them safe to eat.
6. Beware of eating loads of new species at the same time, even if you know what they are
For every foodstuff you can name, somebody out there is allergic to it. Some people are more vulnerable than others; some foodstuffs are more problematic than others.
The same goes for wild mushrooms. If you eat ten new ones at the same time, and one of them causes you to have an allergic or gastric reaction, you'll have no way of knowing which one it was.
7. Don't rely on people identifying stuff for you on the internet
It's you who is actually thinking of eating it, not them.
The internet is a wonderful resource, but beware of people who don't know as much about mushrooms as they think they do. I've seen plenty of things misidentified as an edible species online.
8. Don't rely on google images to return the correct picture if you type its name in
They've often been identified or labelled incorrectly, or the search engine has returned a picture not directly connected to the relevant text.
9. Don't rely on common names
Some common names refer to multiple mushrooms. Some mushrooms have multiple common names.
10. Don't eat Angel's Wings (Pleurocybella porrigens)
Even though your book or internet resource says they are edible, they are in fact deadly.
In 2004, 17 Japanese people died of brain damage after eating these mushrooms. This species is common in Scotland and easily confused with an edible pale oyster mushroom (Pleurotus pulmonarius).