My review was written in January 1985 after watching the film on Showtime.
"Witches' Brew", a/k/a "Which Witch is Which?" is a comedy about witchcraft filmed in 1978, revamped years later by film doctor Herbert L. Strock and finally surfacing on pay-cable after having been shelved for theatrical release and subjected to litigation. Review here is for the record.
An impressive toplined cast is trapped in this amateurish production, revolving around the sitcom premise (in the vein of the "Bewitched" tv series) of housewife Margaret (Teri Garr) helping her college psychology prof hubby Joshua (Richard Benjamin) get ahead via witchcraft. His luck changes for the worse when she lifts all her benevolent spells, after Joshua marks her aid.
Key point of historical interest is that "Brew" relies upon exactly the same premise employed years later in Carl Reiner's Steve Martin hit "All of Me": wicked witch Vivian (Lana Turner) is ailing, but contrives to shift her soul into pupil Margaret's body having willed her fortune to "Margaret". Even the differing mirror image gimmick is trotted out here.
Garr and Benjamin make a comfortable team, but entire cast is hurt by poor sound recording, unfunny dialog ("Bat jowls" is frequently repeated for supposed sure-fire laughs) and terrible continuity.