Sunn O))) co-founders Stephen O'Malley and Greg Anderson began working on new music in early 2018. Following an initial pre-production session at Dave Grohl's 606 Studios in California, they made their way to Chicago to record at Albini's Electrical Audio. Joining the band on Life Metal is composer and frequent live collaborator Hildur Gudnadóttir, who adds vocals, electric cello, and haldorophone to the track "Novae". Additionally, Tim Midyett plays aluminium neck bass and baritone guitars throughout the album, while Anthony Pateras contributes pipe organ to "Troubled Air".