A limited-time item introduced in 2012 as part of the "Marry Bacon" ad campaign, the Bacon Shake was not actually on the menu; a Jack in the Box spokesperson called it "more of a 'secret item' that people can order."
The Bacon Shake actually used Torani bacon-flavored syrup instead of actual bacon.
- Bacon Milkshake: Jack In The Box Adds Absurd Indulgence To Menu. HuffPost. February 9, 2012
- The Bacon Shake from Jack in the Box. GrubGrade. February 2, 2012.