Connection to Identity Within
"Duct Soup" was the last episode of Series VII to be written, as it replaced the script for the "lost episode" "Identity Within". This was due to budget constraints as the script for "Identity Within" was quite ambitious would have been too costly to produce (most of the budget had already been spent on the previous episode "Stoke Me a Clipper"). So, they opted instead for this simple-to-shoot idea of a character driven episode and of filming without special effects and in quickly put together tunnels built on the car park at Shepperton Studios.
Trivia
- Due to its unusual nature as a Red Dwarf episode, "Duct Soup" was not well received by fans, generally speaking.
- Robert Llewellyn (who plays Kryten) states in the Series VII DVD special features that "Duct Soup" is his favourite ever episode of Red Dwarf, due to the character development of the Dwarfers and the backstories developed, as no other Red Dwarf episode had character development on this level. In the episode commentary for the Series VII DVD, Chloƫ Annett (who plays Kochanski) also states that this is her favourite ever episode, while Craig Charles (who plays Lister) counts it among his favourites.
- In reference to another episode, Lister's claustrophobia is mentioned in the "Confidence and Paranoia" episode, where, when he is outside the ship with his Confidence, Lister says that he gets a little claustrophobic in his space suit. Very few episodes show Lister in closed spaces, but when he is, he doesn't make a fuss about it.