 Singer Jackie Lomax, whose debut solo album Harrison had agreed to produce before the Beatles departed for India, said that the Sour Milk Sea symbolises "a fallow period" during each of the Earth's 26,000-year evolutionary cycles, before the planet begins its process of regeneration.As with the other songs he wrote in Rishikesh, "Sour Milk Sea" marked the start of Harrison's return to the guitar as his main instrument, coinciding with a gradual relinquishing of his attempts to master the Indian sitar.In a September 1968 interview, he recalled that he wrote the music "in ten minutes" since he was without a guitar at the time and had to borrow John Lennon's.