The Big Bang Theory Recap with Spoilers - The Fermenation Bifurcation

The episode opens with Penny inviting the gang to a free wine tasting she won at work. Leonard asks why scientists never win things from work, but Sheldon says that he's a scientist for the reward of discovery and not for any external prize. Amy corrects him by pointing out that Sheldon wants a Nobel Prize. Everyone but Sheldon and Bernadette wants to go to the wine tasting, and Sheldon assumes that that means that he'll be hanging out with Bernadette the night of the wine tasting. After some hesitation, Bernadette agrees to hang out with Sheldon, because she obviously didn't pay attention to the show for the last five or so years.

The next day, Raj asks if he can bring Claire to the wine tasting, which prompts Leonard to ask how Raj is dating two women at once. Meanwhile, Howard puts the finishing touches on the prototype to their infinite persistence gyroscope. The prototype works, but Leonard and Howard both note that staring at it too long makes them dizzy. Seconds later, Sheldon (who was filming the test on film) suddenly collapses.

Raj invites Claire to the wine tasting, but Claire is a little apprehensive because she doesn't want things to get "weird". She points out that they've enjoyed a casual relationship so far, but meeting friends is a big step and points out all the different ways it could go wrong.

Before they leave for the wine tasting, Leonard tries out a "scratch and sniff" wine tasting book. Meanwhile, Sheldon preps for his night in with Bernadette by pointing out all the things a pregnant person can't do.

Amy and Howard arrive to the bar first and make some awkward conversation before the rest of the group arrives. Amy quickly points out that Penny's ex-boyfriend Zack is there, but Penny doesn't want to say hello.

Bernadette and Sheldon begin their "fetus friendly festival of fun" by cracking open a bottle of sparkling grape juice before Sheldon shows Bernadette all the different ways to make toast.

While trying to smell wine, Zack pops up to say hello to the gang. He's surprised to see that Penny and Leonard got married, but makes some small talk by asking about Leonard and Howard's invention. He doesn't get the nuances of their navigational system, but he is amazed that they didn't consider the military applications of their device.

Sheldon shows off the various sizes of model trains, and points out that he once swallowed a model train when he was young. Bernadette asks why he likes trains so much, and Sheldon says that they represented order in a chaotic childhood. Bernadette thinks that Sheldon's answer was beautiful, so of course he ruins it by bringing up the model train that rumbled around in his bowels for a few days.

Howard and Leonard admit they were worried about the military uses of their navigational equipment, but Raj points out that any scientific development can be used for military purposes. Claire arrives and Raj instantly starts getting antsy.

Sheldon finishes his presentation of toasts and moves on to the next activity: Dungeons and Dragons. Bernadette doesn't seemed thrilled, until she learns that Sheldon made a custom campaign where she's a tall warrior queen living in a world where only men get pregnant.

Zack heads back to the gang's table to hit on Claire, which causes further questions as to why Raj and Claire are keeping things casual. Meanwhile, Howard and Leonard debate what they should do about the navigational system in the bathroom.

Sheldon and Bernadette continue their game of Dungeons and Dragons, in which Bernadette's character kills a sushi monster and then slips into a hot spring. After the game finishes up, Bernadette thanks Sheldon for a fun night.

Raj asks Zack to lay off on the questions about Claire, which leads to another awkward moment when Zack awkwardly tries to step away from his past comments. Claire realizes that Raj is dating other girls and catches him in a lie, leading to more fun moments of awkward silence.

The next morning, Leonard asks Sheldon about if he's worried about the military applications of their device, but Sheldon said he got through it with the help of two friends that Leonard's never heard of. And that's how the episode ends.