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Can you eat blue staining bolete?

Blue staining boletes are a group of mushrooms that bruise blue when handled. They belong to the bolete family, which have sponge-like pores on the underside of their caps instead of gills. Blue staining boletes are found across North America, Europe, and Asia growing on the ground in both deciduous and coniferous forests.

While some blue staining boletes are edible, others are poisonous. So it’s important to properly identify them before eating. The main edible species are the bay bolete (Boletus badius) and the bitter bolete (Tylopilus eximius). However, there are also toxic lookalikes, such as the devil’s bolete (Rubroboletus satanas), so identification should not be taken lightly.

This article will go over how to identify bay boletes and bitter boletes, look at their edibility and culinary uses, and discuss poisonous lookalikes to avoid.

How to Identify Bay Boletes and Bitter Boletes

Bay boletes and bitter boletes can be identified by their characteristic bruising reactions, pore surface, caps, stems, gills, habitats, and distributions. Here are the key identification features:


– Both bay boletes and bitter boletes stain blue when bruised or injured. This is due to a chemical reaction and is a defining feature of blue staining boletes.


– The pore surface on the underside of the cap is yellowish in bay boletes. Bitter boletes have whitish to pale yellow pores.


– Bay boletes have chestnut brown caps that can be quite velvety. Bitter bolete caps are generally paler brown.


– The stems of bay boletes are reticulated, meaning they have a net-like pattern. Bitter boletes have stems that lack reticulation.


– Neither mushroom has true gills. They both have pores instead. This indicates they are boletes, not gilled mushrooms.


– Bay boletes grow with hardwoods and conifers, especially oak. Bitter boletes grow exclusively with conifers like pine and spruce.


– Bay boletes are found across North America, Europe, and Asia. Bitter boletes occur in North America and Eurasia.

So in summary, look for brown bruising boletes with pores that grow in the appropriate habitats. Use multiple identification characteristics to be certain of the species.

Are Bay Boletes and Bitter Boletes Edible?

Yes, both the bay bolete and the bitter bolete are choice edible mushrooms. When properly identified, they are safe to eat and possess excellent culinary qualities. Here is an overview of their edibility:

Bay Bolete Edibility

– The bay bolete is considered one of the best edible mushrooms. Its rich umami flavor is great in soups, sauces, and as a meat substitute.

Bitter Bolete Edibility

– Despite its name, the bitter bolete is not actually bitter once cooked. It has a mild, nutty flavor and firm texture perfect for sautéing.

Edibility Caveats

– Make absolutely certain of identification, since deadly poisonous lookalikes exist.

– Consume in moderation the first time trying them. Monitor for any adverse reactions.

– Cook them thoroughly before eating. Some people can have gastrointestinal issues with raw mushrooms.

– Avoid any old, bug-eaten, or maggot-ridden specimens. Stick to collecting young, fresh mushrooms.

As long as you’re diligent with identification and preparation, both bay boletes and bitter boletes are considered safe, choice edibles for the table.

Culinary Uses

Once identified and collected, blue staining boletes can be prepared and enjoyed in many culinary applications thanks to their great flavors and textures. Here are some of the most popular ways to cook them:

Bay Boletes

– Sautéed in butter or olive oil and served as a side dish
– Added to soups, stews, and broths
– Ground up to make mushroom patties as a meat substitute
– Baked into a quiche or mushroom tart
– Used as the key ingredient in a mushroom gravy for meats

Bitter Boletes

– Thinly sliced and sautéed with onions and garlic
– Chopped and added to risotto for depth of flavor
– Baked into mushroom caps and stuffed with herbs and breadcrumbs
– Mixed into mushroom duxelles as a stuffing for meats
– Used as a pizza topping instead of usual button mushrooms

The rich, earthy flavor of blue staining boletes takes well to being infused into oils, butter, cream sauces, and other medium. Drying them to use as mushroom powder is also an option for longevity. They provide great umami flavor to enhance all kinds of dishes.

Poisonous Lookalikes to Avoid

While the bay bolete and bitter bolete are edible, some deadly poisonous mushrooms can appear very similar. Consumers must be extremely cautious with identification and mushroom selection. Here are some of the poisonous lookalikes:

Poisonous Species Key Differences
Devil’s Bolete Has a red pore surface and stains blue-red when bruised. Grows under hardwood trees.
Satan’s Bolete Has a bright red cap and stains blue only slightly when injured. Grows with conifers.
Bolete emodensis Has a smooth olive brown cap and stains blue-green. Grows with hemlock in eastern North America.

Consuming any of these poisonous lookalikes can be deadly. When in doubt, always err on the side of caution and do not eat any mushroom you cannot identify with 100% certainty. It’s also best to avoid collecting any boletes with red coloration. Play it safe!

Final Thoughts

In conclusion, the bay bolete and the bitter bolete are two excellent edible mushrooms in the blue staining bolete group. However, proper identification is an absolute necessity before considering eating them. They have toxic lookalikes, including the devil’s bolete, Satan’s bolete, and Bolete emodensis. By learning the key identification markers like bruising reactions, pore colors, stems, and habitat, you can confidently determine if you have an edible blue staining bolete. When cooking with bay boletes and bitter boletes, they lend great flavor to soups, sauces, gravies, quiches, risotto, and more. With caution and diligence, blue staining boletes can be a delicious edible mushroom for the table.


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Kuo, M. (2014). MushroomExpert.Com. Retrieved from

Lincoff, G. H. (1981). National Audubon Society Field Guide to North American Mushrooms. New York, NY: Alfred A. Knopf.

Miller, O. K., & Miller, H. H. (2006). North American Mushrooms: A Field Guide to Edible and Inedible Fungi. Guilford, CT: Falcon Guide.

Schwartz, G. (2018). Boletes: A Global Study of the Fleshy Fungi. St. Louis, MO: Missouri Botanical Garden Press.