In reply to Nick Maclaren ) who wrote this in
, I, Marvo, say :

In article ,
"Uncle Marvo" writes:

IMHO runner bean beans are not as tasty as broad beans. Though when
we were kids, we used to fight over the "fairy slippers" while mum
was splitting the runners. They are very tasty raw, as you say, and
to the best of my knowledge I never died as a result of (usually)
winning the fairy slipper fight.

I do not know at what stage the toxin develops, but I suspect that it
is associated with ripening. Those would have been very unripe.

Interestingly (perhaps) the mycotoxins in wheat are associated with
ripening, but the ripening kills the toxins, rather than the other way
around.