Porcini or Bay bolete

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.

Cap 5-15 cm across, hemispherical with an inrolled margin when young, later becoming convex-flat. Color chestnut-brown, dark chestnut, honey-brown: the rich color of autumn chestnuts. Darker when young, paler with age. Surface smooth, slightly velvety when young, a little tacky in wet weather, dry and matte in dry weather. The cap skin doesn't 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.

Tubular hymenophore: the tubes are attached to the stem or slightly notched. Color yellowish when young, turning yellow-olive with age. The pores bruise distinctly blue to blue-green when pressed, a characteristic feature of the species. Spore print olive-brown.

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.

Stem 5-10 cm tall, 1.5-3 cm thick, thick, meaty, cylindrical, often thickened toward the base. Color yellow-brown to yellow-ochre, reddish toward the base, with fine lengthwise brownish fibers (not a net like porcini's; this is the key difference). When cut, it bruises faintly blue.

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.

Flesh firm, meaty, white to pale yellow. When cut, it bruises blue slowly and faintly (within 1-2 min, not very noticeably), then fades. Smell and taste pleasant and mushroomy, with a hint of fresh nuts.

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.

Pleasant, rich, mushroomy, with a hint of nuts and damp forest.