Large-grained, rounded crystals formed from repeated melting and freezing of the snow.
Under Corn Snow or Melt-Freeze conditions, a crust forms on the surface that will support your weight when frozen, but turns to deep slush during the heat of the day.
In the snowpack, when water percolates through the snowpack it dissolves the bonds between crystals—the more saturated the snow, the more it dissolves the bonds, thus, dramatically decreasing the strength of the snow.
So, why doesn’t all wet snow instantly avalanche? Part of the reason comes from the bonding power – or surface tension – of water itself.
Corn Snow becomes “ripe” when the bonds between the snow grains just start to melt, providing a velvety surface texture perfect for many types of riding. This usually occurs in the morning hours, but the exact timing is aspect dependent. Seasoned corn harvesters know that predicting this timing is an art form honed through experience. If you’re too early, the frozen surface can rattle out your fillings. Worse is arriving too late, after too many bonds have melted and the corn snow has turned into deep, dangerous slush. The slope that may have been perfect an hour ago is now prime for wet snow avalanches.