mspear mspear at telerama.lm.com
Fri Jan 20 21:08:15 EST 1995

Bob Galvan (kasplash at crl.com) wrote:
> recently  a large brown mushroom has appeared in Marin and San Francisco 
> markets under the name "Portobello".  At my novice level of 
> identification skills, I can only say that it looks like Agaricus bitorquis.

> Does anyone know  what this 'shroom really is?   

> Bob Galvan
> kasplash at crl.com

This is our old friend _Agaricus_brunnescense_ (a.k.a. bisporus) var
bisporus.  Yes, the new "wild" taste treat is in fact the same old
common champignon du paris - white button mushroom we all know well. 
Here's what happened:

Growers figured out that they can use a brown colored variety of
mushroom and let them "overmature" until they open, flatten and the
spores mature.  The costs of production are much lower since picking
costs go way down.  The price can be doubled.

On the positive side most people feel that a mature mushroom is much
more flavorful than the closed buttons Americans normally eat.  I feel
the need to have a super-white button is part of the
white-bread-sydrome.  No flavor but looks nice.

On the negative side for growers, however, is the greatly increased
risk of the farms getting a disease call "La France" virus.  This is
totally harmless to humans but can wipe out a mushroom farm.

Portobello's are called "opens" or "flats" in England and Australia
where they have been a staple of the market for decades.  In these
countries you can get a nice breakfast flat fried with egg or breaded
for breakfast.  It's great!

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