"Sour Milk Sea" is a song written by George Harrison and released by English rock singer Jackie Lomax as his debut single on the Beatles' Apple record label in August 1968.

On release, Lomax's single was overshadowed in Apple's "Our First Four" promotional campaign by the Beatles' "Hey Jude" and Mary Hopkin's "Those Were the Days"; it enjoyed only minor success internationally, becoming a top 30 hit in Canada.

"Sour Milk Sea" was one of several songs that George Harrison wrote while staying at Maharishi Mahesh Yogi's ashram in Rishikesh, India, from February to April 1968.

[9][10] With Life magazine labelling 1968 "the Year of the Guru",[11] the Beatles' visit generated wide interest in Transcendental Meditation,[12] and Eastern spirituality generally, among Western youth.

[16] In his autobiography, I, Me, Mine, Harrison says that "Sour Milk Sea" espouses meditation as a means to improve the quality of one's life, as well as advocating a proactive approach when faced with difficulty.

He says he named the composition after a picture titled Kalladadi Samudra, which reflects the theme of Vishvasara Tantra in sacred Hindu texts, particularly regarding "the geological theory of the evolution of organic life on earth".

[4] Singer Jackie Lomax, whose debut solo album Harrison had agreed to produce before the Beatles departed for India,[17] 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.

[18] 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,[19] coinciding with a gradual relinquishing of his attempts to master the Indian sitar.

"[21] Referring to the compositional draft for "Sour Milk Sea", musicologist Walter Everett states that together the various chords suggest "a pentatonic minor scale on A, allowing B♭ as a tritone-related ornament to E7".

[22] Described by author and critic Richie Unterberger as a melody filled with "tense chord ascensions",[1] the composition shares part of its melodic characteristics with "Savoy Truffle", another Harrison song from 1968.

There's nothing much without illumination …Get out of Sour Milk Sea You don't belong there …[4] In the lyrics to the verses, Harrison focuses on the benefits of Transcendental Meditation rather than detailing the way to achieve these results.

[40] Although the subsequent album sessions were marked by disharmony and a lack of cooperation among the band members,[41] author and critic Kenneth Womack comments that the Kinfauns demos "witness the Beatles working in unison and exalting in the pure joy of their music".

[56][nb 2] The line-up consisted of Lomax on vocals, Harrison and Eric Clapton on guitars, Nicky Hopkins on piano, Paul McCartney on bass, and Ringo Starr on drums.

[71][nb 5] In addition, although Clapton had contributed to Wonderwall Music earlier in the year,[76] "Sour Milk Sea" is the first example of him and Harrison sharing the lead guitarist's role on a recording.

[64] Along with "Hey Jude" by the Beatles, Mary Hopkin's "Those Were the Days" and the Black Dyke Mills Band's "Thingumybob", it was one of Apple's "Our First Four" singles,[83] marking the official launch of the label.

[87] In advance of the release date, the company declared 11–18 August to be "National Apple Week"[85][88] and sent gift-wrapped boxes of the four records to Queen Elizabeth II and other members of the royal family, and to the British prime minister.

[89] In an interview to help promote "Sour Milk Sea", Harrison said that the song's message would "[go] above the heads of some people", but it was a "very good record" and indicative of his and Lomax's decision to put artistic merit before commercial considerations.

[110] Record World included the single among its Four-Star Picks and described the song as "Hard rock from one of the new Beatles protégés" with Lomax "lay[ing] out the thick sound".

[99] Although Jackie Lomax had a full and interesting musical career, he was one of Liverpool's unluckiest musicians … his album for the Beatles' Apple label, Is This What You Want (1969), produced by George Harrison, should have been a best-seller.

[47] Among Beatles biographers, Bruce Spizer attributes the commercial failure of Lomax's "great rock single" to the simultaneous release of "Hey Jude" and "Those Were the Days",[81] while John Winn describes it as an "excellent debut" and "an inexplicable flop".

"[117] In his book on the making of the White Album, Uncut critic David Quantick describes the song as "excellent" and rues how, together with Harrison's "Not Guilty", it was passed over in favour of "old toot" such as "Rocky Raccoon" and "The Continuing Story of Bungalow Bill".

[118][nb 9] Less impressed with the track, Richie Unterberger finds the lyrics "a blend of encouragement and mild scolding", and rates it "a serviceable hard-rock number with a bluesy boogie feel" next to the "considerably superior" "Savoy Truffle".

[1] In an online article for Mojo published shortly after Lomax's death in September 2013, Danny Eccleston described "Sour Milk Sea" as "a brilliantly excitable recording".

[122] Among reviews of the Come and Get It compilation, Douglas Wolk of Pitchfork opined that "Sour Milk Sea" "would've been one of the best songs on [the White Album] if George had kept it for himself",[123] while Uncut's David Cavanagh described the track as "sensational".