Nick Maclaren wrote:
It isn't exactly in limited supply :-)
Seriously, there is no real difference between mycorrhiza and
yeast; if the conditions are right, both will replicate madly;
if they are wrong, both will die off; and you can get as much
new material from thriving communities as you want.
It's primarily a damn-fool idea, a.k.a. a way of extracting
money from fools, as the appropriate selection of mycorrhiza
and techniques for getting it established are very tricky, and
not likely to work when done by amateurs (including professional
horticulturists).

Arrgh ... It gets me mad when some fashion takes hold of people and
they all go mad on it, just like the recent totally sold out star
aniseed, supposedly a cure against the chicken flu. It's been lovely
talking to you.