He observed, "We've always screwed around with different types of music during our jams, but we'd say, 'OK let's stop and get back to the album. He sent the band to play foosball in another room while he recorded the strings, which took "like fifteen, twenty minutes, maybe a half an hour at the most. This 25th Anniversary Edition includes the original album, one disc of previously unreleased Nimrod demos, and a live set from Philadelphia recorded one month after Nimrod was released. In 1995, Green Day released Insomniac, which did not perform as well commercially as the band's breakthrough major-label debut Dookie.

A group of editors writing for People also praised the record's "fresh and original" melodies and "quick-tempoed cool", adding, "Kudos to Green Day, young punk's reigning purists, for sticking with what they know best. The album has sold over 3 million copies in the US (triple platinum) and has been certified multi-platinum, platinum, or gold in several other countries, including the UK, Japan, Canada, Australia, and Spain.

Prior to the January 27, 2023 release, the band also released a second demo; a cover of Elvis Costello's " Alison" on January 13, 2023.

The 1997 album will be bundled with a clutch of demoes and a live album recorded at the Electric Factory, in Philadelphia, in 1997. Dirnt explained that the recording was much more loosely structured than previous albums, and that creating songs was the focus as opposed to making a cohesive record. Upon release of the anniversary edition, many critics and fans noted that the demo "Black Eyeliner" was repurposed by Armstrong for two different songs later in his career.The booklet features the lyrics presented as if they were a secret document that had been redacted with black ink, "so they seemed like they were part of something else". Il disco con i demo l'ho trovato molto interessante sia per le tracce inedite sia anche per quelle che già conoscevo in quanto ci sono delle differenze evidenti rispetto alle stesse tracce pubblicate in precedenza! Armstrong wrote "Nice Guys Finish Last" about the band's interactions with the band's lawyers and managers and how "everybody thinks they know what's best for you. Nimrod (25th Anniversary Edition) arrives January 27 next year, digitally, as a 5xLP, and as a 3xCD box set.

The 14 track demos disc includes two unreleased Green Day tracks (“You Irritate Me” and “Tre Polka”), plus a cover of the classic Elvis Costello song “Allison” (previously unreleased). The same woman is also the subject of " She" from Dookie, "Whatsername" from American Idiot (2004) and "Amanda" from ¡Tré! On July 6, 1998, the record was certified double platinum by the Canadian Recording Industry Association for shipments of over 200,000 copies. Nimrod debuted at number ten on the Billboard 200, selling 81,000 copies in its first week of release, and remained on the chart for 70 weeks.

Recorded at Conway Recording Studios in Los Angeles, the album was written with the intent of creating a set of standalone songs as opposed to a cohesive album.