Boletus betulicola or Brown birch bolete

The cap is large, 7–25 cm across, hemispherical and cushion-shaped in young mushrooms, opening with age to convex-flattened. The color is light — from almost white and cream in young ones to light chestnut, hazel or the color of freshly baked bread in mature ones; noticeably paler than the pine bolete or summer bolete. The surface is dry and matte, faintly velvety to the touch when young, slightly shiny in wet weather. The margin is even, and the skin does not peel.

Cap 5–15 cm across, at first spherical or hemispherical, later cushion-shaped. The surface is smooth or slightly wrinkled, dry or a little sticky in wet weather. Color ranges from grayish brown to dark brown, more rarely almost black.

The hymenophore is tubular, free or slightly notched at the stem, and separates easily from the flesh. In young mushrooms the tubes are pure white; as the spores mature they turn yellow and later take on an olive-greenish tint. The pores are small, round, and the same color as the tubes. An important diagnostic feature: when pressed or damaged, the hymenophore does not turn blue or change color — this sets true porcini apart from many bluing boletes.

The hymenophore is tubular. The tubes and pores are white, small in young mushrooms and wider in mature ones. When pressed, the pores turn slightly brownish, but there's never any bluing: unlike in the red-capped scaber stalks, the flesh doesn't blue even at the stem base.

The stem is massive, 5–20 cm tall and up to 4–6 cm thick, bulbous and swollen when young, lengthening with age to club-shaped or almost cylindrical. The color is whitish, cream or light brown, often paler than the cap. The upper part shows a fine pale net (reticulum) — white veins on an even paler background, not as contrasting as the dark net of the bitter bolete. There is no ring and no volva.

Stem 8–18 cm tall, 1.5–3 cm thick, cylindrical, fairly long and slender compared with the cap. The surface is white or grayish, densely covered with dark, fibrous scales — the hallmark of the genus Leccinum. The stem is firm and fibrous.

The flesh is thick, firm and white, sometimes faintly brownish under the cap skin. When cut, the color does not change — it does not turn blue, red or dark; this is one of the key features of true porcini. The texture is springy and meaty, hard in young mushrooms and slightly softer with age. The taste is mild and pleasant, not bitter, with a delicate nutty note.

The flesh is firm and white; when cut it doesn't change colour or turns slightly pinkish, and after a few hours may become a little greyish or brownish. It darkens to grey-black only when cooked. The taste is mild and neutral. The cap skin doesn't peel.

The smell is pleasant and richly mushroomy, with a warm nutty note — the classic porcini aroma. When cut it is fresh and clean, and when dried it grows much stronger, filling the house with that rich mushroom scent people dry porcini for. There are no chemical, sour or unpleasant notes at all.

The smell is unobtrusive, pleasant and typically mushroomy. The aroma intensifies with cooking. When dried, the brown birch bolete takes on a rich scent that falls short of porcini but is noticeably better than most other pored mushrooms.