Many food products show a high level of vertical and horizontal product differentiation. Manufacturers may instrument product differentiation to limit competition and to increase price dispersion. In this paper, we estimate a panel error correction cost pass-through model for the German yoghurt market over a six year period (t = 312) to determine the impact of product differentiation on price competition between individual brands and varieties of yoghurt. We find that more differentiated products show higher markups, reduced equilibrium cost pass-through and lower speed of cost-price adjustments. The results indicate that manufacturers (and/or retailers) use product differentiation to limit price competition.