Shiitake mushrooms can be one of the most sustainable foods in your diet! While the majority of shiitake mushrooms produced worldwide have been grown on sawdust block in a non-natural setting, it is fully possible for shiitake mushrooms to be produced on natural hardwood logs in a forest setting. This approach to shiitake mushroom production is called "forest farming" and it has become an especially popular way of growing shiitake mushrooms in the U.S, where there are now more than 200 shiitake mushroom growers. Unfortunately, forest farming is not a requirement for organic certification of shiitake mushrooms. However, all of the plant crop standards in the National Organics Program regulations apply to shiitake mushroom production, and so the combination of these two features—certified organic shiitake mushrooms that have also been forest farmed—can make a great food choice in terms of sustainable agriculture. Just look for the USDA's organic logo on your shiitake mushrooms to determine if they are certified organic. Then check for information about forest farming on the packaging. If no information is provided, there is a good chance that your shiitake mushrooms were not forest farmed. For this reason, we encourage you to ask your store staff or contact the product manufacturer to determine if your shiitake mushrooms were grown on hardwood logs in a natural forest environment.