Consuming food from the wild is a source of great joy and satisfaction. It can also kill you if you are not careful. Do not risk your life with one casual mistake. Even mycologists make mistakes, so don't experiment with anything that you have not very carefully cross-checked with possible poisonous look-alikes. If you are just starting to collect and eat wild mushrooms, don't rely solely on books or websites for your information. Go hiking with experienced experts, who can show you how to identify the important characteristics of edible and poisonous mushrooms.
I am not a qualified mycologist, nor would I ever pretend to be. I am presenting this information in order to share my enthusiasm and love for something with which I am only a beginner. Humility and caution are essential if you want to eat wild mushrooms without getting sick or shortening your life. I encourage learning for the sake of learning, so learn to identify the species that are not edible, as well as the ones you can eat. Respect all of them. And remember this most of all:
When you are eating a mushroom for the first time, go slow. Even the most prized edible mushrooms create adverse reactions in some people. The same is true even with Agaricus bisporus, the white button mushrooms you find at every market. When I try a new edible mushroom, I generally sauté one specimen quite thoroughly, and eat only a few bites. I will wait a few hours before I eat the rest of the specimen, paying attention to any digestive unrest. I typically wait at least 6-8 hours, or until the following day, before I begin to eat the remainder of the collection. This way I will be certain that I have no unpleasant reactions before I eat a large quantity, or serve it to friends.
You should never serve wild mushroom dishes to friends without telling them what they are eating. Don't be insulted if they don't trust your judgement, and never pressure them into eating something they don't want to. Again, even "safe" mushrooms can make some people sick, so prepare your meals with caution and full disclosure.
You can also make yourself sick if you eat large amounts of any mushroom, including ones that you have eaten happily in the past. Even the safest edible mushrooms contain numerous complex organic compounds that may be difficult to break down in the digestive system. You should cook with them in moderate quantities, as an accent in your meal, to avoid overloading your system.
Sometimes, scientists change their assessment about whether a certain mushroom species is "safe." Sometimes, edible species can intergrade with genetically similar poisonous species. For example, some reports claim that intermediary gradations of Amanita species can slowly cause long term liver damage. Whether or not this is true, caution remains our best friend!
I personally feel that you should never serve mushrooms raw, even ones that you buy in the store. Raw mushrooms are essentially indigestable, and can cause flatulence or even diarhea. Some studies have even found trace amounts of carcinogens in raw samples of the innocuous button mushroom Agaricus bisporus. Such compounds tend to break down when cooked, however. Cooking also appears to render edible several species that are generally considered toxic, such as Boletus satanis and Gyrometra esculenta. You should not start collecting these poisonous species with the idea that they'll be safe once cooked, but it's nice to know that cooking can help protect you in rare cases if you make a stupid mistake. In summary, never make stupid mistakes, and always cook your mushrooms.
As a final warning, consider very carefully the environment from which you collect your mushrooms. Avoid polluted areas, busy roadsides, trash heaps, and gardens where people have used pesticides and chemical fertilizers. Mushrooms can collect and concentrate chemicals from the soil around them. Thus, urban mushrooms can become toxic from human activities, accumulating pesticides and heavy metals such as lead and mercury that might prove far more harmful than the mushroom itself. For several years after the nuclear accident at Chernobyl in western Russia, wild mushrooms throughout eastern Europe and Scandinavia contained measurable concentrations of radioactive isotopes, and European governments recommended strongly against collecting them.
This last point leads me to a different concern altogether, which is preservation of habitat. Mushrooms thrive in healthy woodlands, and humans thrive when they have plenty of healthy wilderness nearby to enjoy. As my passion for observing nature grows, I can't help but notice how increasingly difficult it can be to locate undisturbed natural places. My obsession with mushrooms has taken me out into open spaces more than ever before, and my respect for the wilderness keeps growing. I am increasingly aware of how quickly we humans are destroying natural habitats throughout the world. The destruction of wilderness reduces the diversity of species in all kingdoms of life - plant, animal, fungus and more. We are all responsible for contributing to the destruction of habitats through our hunger for luxury and carelessness in our consumption. Mycophiles can do their small part to help preserve what little wilderness we have left, even in our collecting habits, if not with our miniscule political and economic voice. When we collect mushrooms for the table, we should be careful to leave the forest duff in good condition, so as not to disturb mycelial growth. We should also collect only what we can use. This caution and respect for the forest environment can lead to several good consequences for mushroom hunters. First, we get to experience the joy of walking through an undisturbed forest; second, we'll be able to return to more mushrooms in the future; and third, no-one can see where we've been, so they won't be able to find our secret patch of boletes or chantrelles !
So eat wisely, and respectfully.
- Robert Rich