A method and apparatus for melting a raw material such as glass. The method comprises a creating a flow of raw material interrupted by a heated phase separation barrier (3,31,32), wherein melting is achieved by transfer of heat from the phase separation barrier to the raw material. The process comprises: providing solid raw material to the phase separation barrier, wherein the phase separation barrier supports the solid raw material; heating the phase separation barrier to a temperature which is (a) at least 700°C and (b) sufficient to cause melting of the solid raw material which contacts the barrier, wherein any melted raw material formed on contact with the phase separation barrier flows off or through the phase separation barrier; and collecting the melted raw material; wherein the phase separation barrier causes separation of the solid and melted phases within the flow of the raw material. Two or more melters may be used in parallel and the resultant melted raw materials mixed together in the melted state. In addition, there is provided a method and apparatus for producing a melt comprising a mixture of melted raw materials. The apparatus comprises two melting chambers connected via outlets to a homogeniser.