  The granular Leidenfrost effect (B. Meerson et al, Phys. Rev. Lett. {\bf 91},
024301 (2003), P. Eshuis et al, Phys. Rev. Lett. {\bf 95}, 258001 (2005)) is
the levitation of a mass of granular matter when a wall below the grains is
vibrated giving rise to a hot granular gas below the cluster. We find by
simulation that for a range of parameters the system is bistable: the levitated
cluster can occasionally break and give rise to two clusters and a hot granular
gas above and below. We use techniques from the theory of rare events to
compute the mean transition time for breaking to occur. This requires the
introduction of a two-component reaction coordinate.
