According to the liner notes of the album it was "recorded live at 60 6th street in San Francisco in one day, one week after the gay pride parade 2009 on a tascam 388". 60 6th Street in San Francisco was, at the time, the location of Club Six, a hip hop club where John Dwyer worked. According to Dwyer, Club Six was "[A] big, airy room with a nice wooden stage, hardwood floors and really high ceilings. I gave them $500 to record in the room for 12 hours." The whole album was recorded "live" with no overdubs in an attempt to recreate the feeling of the band's live performances. Mike Donovan, the leader of Sic Alps, was the only guest musician on the album. Donovan had previously appeared on OCS' 2005 album 3&4, when he sang vocals for the song "Burning Beauties". Like their other albums, Warm Slime was recorded and mixed by Chris Woodhouse.
The cover art was made by Kyle Ranson. He would later go on to create the cover for Putrifiers II in 2012.
Warm Slime was the only significant release to be excluded from Burger Records' 2011 series of Thee Oh Sees cassettes. Each cassette in the series featured two albums by the band, one for each side of the tape. Instead, Warm Slime was issued on cassette in 2012 by itself. Only 300 were made (same as each of the releases in the 2011 series), and they were individually numbered as a limited edition.