Ask Paul: What’s the Difference Between Cremini and Button Mushrooms?

Laurence asked: “Is it true that cultivated mushrooms are all the same species?”

Not all. But a few of the common fresh mushrooms we love are all varieties of one species, Agaricus bisporus.

Many species of mushrooms can’t be successfully grown in captivity, at least not on a commercial scale, but A. bisporus was first cultivated centuries ago in Europe. The mushrooms were small, mild-tasting (especially when grown on a mild-tasting medium), and brown-skinned: They’re what we call cremini today.

Their ease of growing plus their deliciousness made them very popular—until 1925, when a Pennsylvania mushroom farmer named L. F. Lambert found a mutant strain among his A. bisporus crop. In a sea of brown mushrooms, this one was white as snow.

Lambert propagated the new mushroom and sold it under the name “Snow White.” With its clean, appealing appearance, the white button mushroom rapidly displaced the brown variety and became the dominant mushroom, making up 90 percent of U.S. mushroom consumption today.

Somewhere around 1970, natural, browner foods, like wheat germ and raw sugar started to become popular, and the brown strain of A. bisporus, now with the charmingly Italian-sounding name cremini, found a new audience. The U.S. Mushroom Council says that cremini mushrooms have a “deeper, earthier flavor” than white ones, but I was unable to verify that in a home blind tasting.

Both brown and white varieties are harvested young, while they’re small. If allowed to grow a few days longer, they develop broad caps that are several inches in diameter. These were not widely grown or sold until the 1980s, when someone put the label “portabella” (or “portobello,” or other variations) on them, and a third, newly captivating type of A. bisporus took kitchens by storm.

Yes: Button mushrooms, cremini mushrooms, and portabella mushrooms are all the same species. Think that’s amazing? Wait until we get to Brassica oleracea.

Ask Paul Adams, senior science research editor, about culinary ambiguities, terms of art, and useful distinctions: paul@americastestkitchen.com