  When making contact with an undercooled target, a drop freezes. The colder
the target is, the more rapid the freezing is supposed to be. In this research,
we explore the impact of droplets on cold granular material. As the
undercooling degree increases, the bulk freezing of the droplet is delayed by
at least an order of magnitude. The postponement of the overall solidification
is accompanied by substantial changes in dynamics, including the
spreading-retraction process, satellite drop generation, and cratering in the
target. The solidification of the wetted pores in the granular target primarily
causes these effects. Owing to the small size of pores, solidification there is
sufficiently fast to match the characteristic timescales of the impact dynamics
at moderate undercooling degrees. As a result, the hydrophilic impact appears
`hydrophobic', and the dimension of the solidified droplet shrinks. A monolayer
of cold grains on a surface can reproduce these consequences. Our research
presents a potential approach to regulate solidified morphology for subfreezing
drop impacts. It additionally sheds light on the impact scenario of strong
coupling between the dynamics and solidification.
