In this short note we present a method and describe a simple apparatus for use with simple, fractional, and steam distillation operations in which the operator requires a precise measurement of instantaneous distillate composition as the distillation proceeds. There are many examples in which such a measurement will play a critical role. One such example is in the measurement of boiling or distillation curves, where one desires an explicit measure of distillation process temperatures as a function of distillate volume fraction. The ability to augment temperature-volume distillation curves with composition information is very helpful. The optimization of critical distillation conditions for the separation of sensitive solutes is another example in which instantaneous distillate composition is of value. The purification of reactants before a reaction is still another example. In all of these cases, it is the instantaneous composition that emerges from the condenser that is needed, rather than the integrated composition of the distillate that accumulates in the receiver. In this note, the apparatus and method are described, and an example is given with a mixture of n-decane/n-tetradecane.