The beard was made much the same way as the rest of the sculpt by bending wire int a sort of long banana 'U' shape and then criss-crossing diagonally to give it some strength, but i didnt bother with twisting wire around the first piece of wire as it didnt need it, then you squash on some more clay and press it onto the chin (st2.12 & st2.13) and in pic st2.14 you can see a bit of the wire frame.
Add more clay to get the basic overall shape (st2.15) now you can start to add detail (st2.16), this was done with a blunt ended modelling tool a bit like a dental tool (see the end of 'how to' for tools used).