 Although it originated as an acoustic guitar song, the official recording of "Sour Milk Sea" is in the heavy rock style typical of the late 1960s.Greene comments on the appropriateness of this "hard-driving, blues guitar medium" as a way for Harrison to directly convey "a simple rule of thumb" regarding the human condition.The Beatles recorded a demo of "Sour Milk Sea" at Harrison's Esher home, Kinfauns, in late May 1968, while preparing material for their self-titled double album (also known as "the White Album").