The Collaborative International Dictionary of English v.0.48:

Crustiness \Crust"i*ness\ (-[i^]-n[e^]s), n.
   1. The state or quality of having crust or being like crust;
      hardness.
      [1913 Webster]

   2. The quality of being crusty or surly.
      [1913 Webster]

            Old Christy forgot his usual crustiness. --W.
                                                  Irving.
      [1913 Webster]