Porcini or Boletus betulicola

Cap 7–30 cm across, spherical or hemispherical in young mushrooms, becoming cushion-shaped and spread out over time. The color varies from light brown to dark chestnut or reddish brown depending on light and forest type: caps are darker in spruce woods and lighter in pine forests.

The cap surface is dry, smooth or slightly wrinkled, and can be a little sticky in wet weather. The margin is even or slightly wavy, inrolled in young mushrooms. The skin doesn't peel.

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.

The hymenophore is tubular and separates easily from the cap flesh. In young mushrooms the tubes are white, later turning yellow; in mature ones they're yellow-green or olive. The pores are small, round, uniform in color and don't change color when pressed.

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.

Stem massive, 5–20 cm tall and 3–10 cm thick, bulbous or club-shaped in young mushrooms, later cylindrical. Color from whitish to light brown. The surface is covered with a characteristic white or cream net pattern, most distinct in the upper part of the stem.

There's no ring and no volva. The base of the stem is often thickened.

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.

The flesh is dense, juicy and white, and doesn't change color when cut or damaged — this feature sets porcini apart from a number of poisonous lookalikes. In old fruiting bodies the flesh becomes spongy and yellowish.

The taste is mild, nutty and slightly sweet. The stem flesh is denser and more fibrous than the cap flesh.

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 smell is pleasant, unobtrusive, mushroomy with light nutty notes. With cooking and drying the aroma intensifies and takes on a deep, rich woody, foresty character. It's for dried porcini that the mushroom is so valued in cooking — no other dried mushroom gives such a pronounced taste and smell.

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.