In the ice cream freezer barrel,
the rate at which the mix freezes determines the initial size and
number of ice crystals. As water in the ice cream freezes, the stabilizer
in the unfrozen matrix becomes more concentrated. The viscosity
increases, and a gel structure forms. This increased viscosity and
the gel structure immobilize water during freeze-thaw cycling, explains
Ulen. Water is obstructed from migrating to and reforming around
existing ice crystals, thus preventing the growth of large crystals
that contribute to an icy or grainy texture.