  Ices, including water ice, prefer to recondense onto pre-existing nuclei
rather than spontaneously forming grains from a cloud of vapor. Interestingly,
different potential recondensation nuclei have very different propensities to
actually nucleate water ice at the temperatures associated with freeze-out in
protoplanetary discs. Therefore, if a region in a disc is warmed and then
recooled, water vapor should not be expected to refreeze evenly onto all
available grains. Instead it will preferentially recondense onto the most
favorable grains. When the recooling is slow enough, only the most favorable
grains will nucleate ice, allowing them to recondense thick ice mantles. We
quantify the conditions for preferential recondensation to rapidly create
pebble-sized grains in protoplanetary discs and show that FU Orionis type
outbursts have the appropriate cooling rates to drive pebble creation in a band
about 5 astronomical units wide outside of the quiescent frost line from
approximately Jupiter's orbit to Saturn's (about 4 to 10 au). Those pebbles
could be of the appropriate size to proceed to planetesimal formation via the
Streaming Instability, or to contribute to the growth of planetesimals through
pebble accretion. We suggest that this phenomenon contributed to the formation
of the gas giants in our own Solar System.
