The Frost Bolete
Exsudoporus frostii
"Mm she the devil!" - Doja Cat
The Apple Bolete - The Candy Apple Bolete
QUICK ID:
Color - blood red
Height - up to 15 cm
Cap diameter - up to 15 cm
Spore print - olive brown
Edibility: edible, but has toxic look-alikes
What's in a [common] name?
Exsudoporus frostii was first described in 1874 by mycologist, John Lewis Russell, a Salem, MA resident. He named it Boletus frostii after his friend and amateur mycologist, Charles Christopher Frost, but there is some evidence to suggest that Frost was the first to actually describe this mushroom. There were several genera changes over the last century and a half, but in 2014, the genus Exsudoporus was created which remains under some contention still to this day. Some mycologists currently refer to it as Butyriboletus frostii and I’ve even seen official government websites still using the genus Boletus. So what’s reallllly in a name?? The most recent publication on the matter argues in favor of Exsudoporus as its official genus (Bikelova et al. 2022).
As for vernacular names, it is commonly referred to as the Frost Bolete after Frost or the Apple or Candy Apple Bolete due to its vivid red color which resembles that of an apple.
The Frost Bolete
Exsudoporus frostii
Photo taken by author.
Description and Ecology
Its first distinctive feature is its blood red convex cap which stands out against the forest floor. When young, its pore surface is as red as its cap, but turns brownish to yellow with age. As it ages, the cap also flattens out. Its stalk is heavily and coarsely reticulated. It can have a yellowish undercoat with blood red reticulation. The mycelium at the base of the stalk is white. The flesh is pale yellow to white and stains blue when cut. Its spore print is olive brown.
The Frost Bolete can be found across the United States from Texas up to Maine through the summer and into the fall. It forms mycorrhizal associations with hardwood trees such as oaks.
The Frost Bolete
Exsudoporus frostii
Photo taken by author.
Warning and Culinary Uses
The Frost bolete is considered to be edible, although most do not think it has a distinctive taste. The exudates on its pore surface are said to have a lemony flavor which may carry over in cooking. I have tasted the exudate and it was sour, but not necessarily citrusy. Unfortunately, there are several poisonous look-alikes, so while this mushroom is edible, it is best avoided. Within the foraging community, there is a short saying: “Pores of red- may put you to bed!” These look alikes include Boletus rubreoflammeus, Boletus flammans, and Boletus satanas.
The Frost Bolete
Exsudoporus frostii
Photo taken by author.