The present invention is directed to a modular distillation system incorporating a removable capsule for containing source material for extraction. Through the action of the invention, the steam distillation process described herein produces a substantially larger amount of volatile oil than a distillation system that does not use an enclosed, modular system. The present invention provides for an apparatus that allows for greater contact between the steam and plant matter during the distillation process through the use of a closed removable capsule containing relatively small amount of plant matter. Additionally, the present invention is directed to a system that allows the generation of higher quality distillate and considerably higher quantity of volatile oil extracts by forcing the steam to evenly disperse through a removable capsule, and by preventing the condensed liquid to return back to the boiling water within the vessel.