  We use the fusion construction in the twisted quantum affine algebras to
obtain a unified method to deform the wedge product for classical Lie algebras.
As a byproduct we uniformly realize all non-spin fundamental modules for
quantized enveloping algebras of classical types, and show that they admit
natural crystal bases as modules for the (derived) twisted quantum affine
algebra. These crystal bases are parametrized in terms of the $q$-wedge
products.
