What I Learned From Wikipedia Today

[upsilon]

Portobello mushrooms and the common mushroom (aka the white mushroom or the button mushroom) are actually the same species. True, the variety is slightly different, but it's mostly just a difference in coloration (Portobellos being browner). The real difference between the two is just a few days in age before being picked.

Comments

[dolohov]

Huh. That should not have surprised me, given how similar they are. There is a toughness/texture issue, but not more than I would expect from maturation. That explains how portobellos were able to catch on so fast, too.