Disclosed are methods for the formation of a rubber/filler/curative/plasticizer compacted masterbatch which may be performed in two ways. In one embodiment, a rubber and a filler are intimately mixed for a time and under shear conditions sufficient to form a free flowing associated composition, then the composition is mixed with a plasticizer and a curative to form the compacted masterbatch. Alternatively, the starting material may be an already-formed free flowing associated composition of rubber, filler and optional curative, which is mixed with a plasticizer and optional curative to form the compacted masterbatch.