The Big Bang Theory - The Fermentation Bifurcation
The gang goes to a wine bar and runs into Penny's old boyfriend, Zack. Also, Bernadette gets stuck spending the evening with Sheldon when she can't go wine tasting with the group, and things don't go as planned when Koothrappali introduces his new girlfriend, Claire.
- Season: 9
- Episode: 22
- Runtime: 30
- Aired: April 28th, 2016 at 20:00