At a glance, modern extraction machines can seem a little mysterious: plant material is added to an extraction chamber, processing parameters are chosen, the extraction process is carried out, and an output of material is collected. Part I of this series examines the two main biologically inherent starting-material influences. These include total mass of material loaded in the extraction chamber at the start of an extraction and the component makeup of the material with regards to content of compounds of interest. An extensive review of percent extraction efficiency calculations is also presented.