An electronic cigarette vaporizer includes a heating element for heating an e-liquid and a microcontroller; the microcontroller determines the type and/or characteristics of the e-liquid being used and uses that as an input to automatically control the power delivered to the heating element to heat the e-liquid in a manner suitable for that specific type of e-liquid, or e-liquid with those characteristics. The e-liquid can be supplied from a cartridge and that cartridge then includes a record of the type of e-liquid stored in the cartridge and/or its characteristics and the microcontroller reads that record or is provided data from that record. A variable for the type of e-liquid and/or its characteristics is the water content of the e-liquid.