The album was essentially a 'posthumous' Mothers release having been released after Frank Zappa dissolved the band.
Ian Underwood's contributions are significant on this album. The album, like its counterpart Weasels Ripped My Flesh, comprises tracks from the Mothers vault that were not previously released. Whereas Weasels mostly showcases the Mothers in a live setting, much of Burnt Weeny Sandwich features studio work and structured Zappa compositions, like the centerpiece of the album, "The Little House I Used to Live In", which consists of several movements and employs compound meters such as 11/8 with overlaid melodies in 6/8 and 4/4.
The guitar solo portion of the "Theme from Burnt Weeny Sandwich" is an outtake from an unused extended version of "Lonely Little Girl" from the 1967 sessions for the We're Only in It for the Money LP. Zappa and Art Tripp later added multiple percussion overdubs for the released version (The source recordings for the percussion overdubs were issued in 2012 on the posthumous Zappa release Finer Moments under the title "Enigmas 1-5").
"Valarie" was originally intended to be released as a single coupled with "My Guitar Wants to Kill Your Mama". However, either Zappa or his label, Reprise Records, cancelled its release, resulting in its inclusion on the LP.
"Igor's Boogie" is a reference to a major Zappa influence, composer Igor Stravinsky.
Cal Schenkel has noted that his unique cover art for Burnt Weeny Sandwich was originally commissioned for the cover of an Eric Dolphy release.
The piano introduction of "Little House I Used to Live in" appears in Yvar Mikhashoff's four CD set "Yvar Mikhashoff's Panorama of American Piano Music".
The song title for "Little House I Used To Live In" was changed to "The Little House I Used To Live In" on all CD reissues.