Lomax carried out radio promotion for the single in November, while he and Harrison were in the US recording further material for Lomax's album, "Is This What You Want?" Although the single received considerable promotion, it was a surprising commercial failure. "Sour Milk Sea" failed to chart in Britain. In America, the song reached number 117 during a two-week run on the Bubbling Under listings of "Billboard"s Hot 100 chart, and "The Eagle Laughs at You" placed at number 125. "Sour Milk Sea" was a hit in Canada, however, peaking at number 29 on the "RPM" 100 in November 1968. In a 1974 feature on his career in "ZigZag" magazine, Lomax said that the song's release in tandem with "obvious" hits like "Hey Jude" and "Those Were the Days" jinxed its commercial performance, since radio stations were reluctant to risk alienating other record labels by featuring all four Apple singles too heavily on their playlists. Lomax added: "So they kind of lost me in the shuffle." The song's exhortation to "Get back to where you should be" was partly appropriated by McCartney in his lyrics to "Get Back", which the Beatles recorded in January 1969. In March that year, both sides of Lomax's single were included on "Is This What You Want?", which was his only album for Apple. The album similarly failed to achieve commercial success, a result that perplexed the Beatles, who continued to believe in Lomax's talents. In June 1971, Apple re-released "Sour Milk Sea", with "Fall Inside Your Eyes" on the B-side, but this single also failed to chart. In 2010, Apple reissued "Is This What You Want?" as both an individual release and as part of the seventeen-disc box set titled "The Apple Box". "Sour Milk Sea" also appeared on the accompanying two-CD compilation, "". In conjunction with these releases, a mono mix of the song was made available for digital download. Lomax's 2015 box set "Rare, Unreleased and Live, 1965–2012" includes live versions of "Sour Milk Sea" and "The Eagle Laughs at You", recorded by him for BBC Radio. On release in 1968, the single received favourable reviews from music critics. Derek Johnson of the "NME" called it a "raving r-and-b number" that was "powerfully interpreted" by Lomax and "peppered with twangs".