The Fermentation Bifurcation Season 9, Episode 22 -  Aired April 28, 2016

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.

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Guest Stars: Brian Thomas Smith as Zack, Alessandra Torresani as Claire

Writers: Steven Molaro (Story), Jim Reynolds (Story), Anthony Del Broccolo (Story), Chuck Lorre (Teleplay), Steve Holland (Teleplay), Tara Hernandez (Teleplay)

Director: Nikki Lorre

Viewers: 14.13 million Households Rating: 9.3/16 Adults 18-49 Rating: 3.3/13

Available on iTunes

Episode Notes

  • The title refers to the two different ways the gang spend the evening: Leonard, Penny, Amy, Raj and Howard at a wine tasting event, while pregnant Bernadette spends the night with Sheldon.

> Sheldon's Spot

After spending an enjoyable evening playing Dungeons and Dragons with Bernadette to get her mind off being pregnant, Sheldon tells Bernadette that any time she wants a break from being "Bernadette the Pregnant", "Bernatrix the Warrior Queen" is waiting. When Bernadette says she might take him up on that offer, Sheldon points out that it's only good until the third trimester as he can't risk getting amniotic fluid on his spot.

Episode Quotes

Leonard: Hey, did you ever think about the military applications for the guidance system?
Sheldon: Of course.
Leonard: Does it bother you?
Sheldon: No, it did at first. But then I talked it through with Frank and Alicia, and they really helped put things into perspective.
Leonard: Who are these people?
Sheldon: Leonard, friends are like toilet paper. It's good to have extras under the sink.

Zack: I see what you're saying. She's not so great.
Raj: Don't listen to him. He says crazy things all the time. Uh, watch. Marco.
Zack: Polo.

Raj: So, uh, what are you guys talking about?
Claire: Your friends were just telling me about all the other girls you're dating.
Raj: Why would you do that? I specifically asked you not to do that.
Penny: We didn't.
Amy: You just did.
Zack: Wow. Maybe none of you guys are smart.

Penny: All right, well, let me know if you guys want to go.
Raj: I would love to. I do enjoy the complexity of an aged Pinot noir.
Leonard: I'm sure that would pair nicely with your fried nuggets of chicken.

Raj: Hey, dude, you're killing me with Claire.
Zack: What are you talking about?
Raj: I mean, come on, look at you. You're classically handsome, you've got a swimmer's body. Next to you, I look like me.

News Stories

Title Date Posted
922 'The Fermentation Bifurcation' Press Release April 26, 2016

CBS has issued the press release for the next episode of The Big Bang Theory, "The Fermentation Bifurcation", which airs this Thursday. Brian Thomas Smith reprises his role as Penny's ex-boyfriend, Zack.  Full story


As they eat dinner in the apartment, Penny tells the group she won a night of wine tasting at work and asks if her friends are interested. Raj and Amy are up for it, but Sheldon doesn’t want wine again. Howard says they won’t be able to go as Bernie can’t drink, but she says he should go. Bernadette is less than enthusiastic when Sheldon suggests he and Bernadette spend the evening together instead. Now that she’s pregnant, Bernadette is avoiding many of the things he’s been avoiding his whole life. Bernadette relents and agrees to give it a try.

In Howard’s lab, Raj asks if he can bring Claire to the wine-tasting as he’s been wanting her to meet the guys. After Raj admits he’s still dating Emily, Leonard wonders how this works. Raj says they know they’re not exclusive, but they don’t ask too many questions. Sheldon likens this to his online gaming mates, Frank and Alicia. After Howard says they’re ready, the guys successfully test their guidance system.

In Raj’s apartment, he phones Claire to ask if she’s free Saturday night to attend a wine-tasting with his friends. Claire is free but she wonders whether meeting his friends is too big a step. Raj doesn’t think it’s a big deal, but Claire points out they’ve been keeping things casual. What if she meets his friends and they don’t like her or she doesn’t like them?

In the apartment, Leonard is using a scratch ‘n sniff wine-tasting book to prepare for the evening ahead. Before they leave, Penny asks Sheldon whether he is still hanging out with Bernadette tonight. Sheldon confirms they are and is happy to share the list of things he and Bernadette will be avoiding.

At the wine tasting, Howard and Amy are stuck for things to say when they are the first to arrive. They are relieved when Leonard, Penny and Raj finally show up. As Raj explains Claire is meeting them there, he begs his friends not to ask too many awkward questions about their relationship as they’re trying to keep it casual. When Amy sees Penny’s old ex-boyfriend, Zack, across the room, she asks if Penny’s going to go say hi to him. Penny isn’t sure about going over to see him.

When Bernadette arrives at the apartment, she tells Sheldon she’s brought sparkling cider. Sheldon details the fetus-friendly evening he has planned: an in-depth look at the world of model trains, followed by an exploration of the different ways to make toast.

Leonard can’t smell anything as his friends discuss the notes they’re picking up from the wine. When Zack comes over to talk to the group, he notices Leonard and Penny are married. Apart from their time together, Zack admits he was always rooting for them two of them. When Zack asks what’s up in the science world, Howard explains they’ve been working on a navigation system. After Howard explains it can be put in satellites or rockets, Zack wonders whether it could be used for weapons or war stuff. Leonard doesn’t think the military would be interested in their little project. After they admit their system is much better than what the military use now, Zack wonders whether they really are smart.

Back in the apartment, Sheldon talks Bernadette through the different sizes of model train gauges. After she asks him what it is about trains that he likes so much, Sheldon admits that life was confusing and chaotic for him as a child, and trains represented order. He could line them up, categorize them and control them. Bernadette thinks that’s lovely.

Leonard and Howard admit they have both been worried about the military use of their system. Raj argues they can’t let this stop them as virtually any scientific advancement can be used for destructive purposes. When Claire turns up, Raj awkwardly introduces her as his friend he is casually dating.

Bernadette is bored as Sheldon describes the various types of toast, including something he calls “Star Wars toast”. Things get worse when Sheldon says it’s time for Dungeons and Dragons. Bernadette is not enthusiastic about playing the game, but Sheldon insists she will enjoy it as he designed it especially for her. Sheldon tells Bernadette her character is Bernatrix, a warrior queen who is strong, beautiful and tall. Bernadette likes the idea of being tall. Sheldon mentions there’s a lot she will like in this universe, including the fact it is the men who carry the babies.

At the wine-tasting, Amy tells Claire they’ve heard so many wonderful things about her, but she is thrown when Claire asks what. When Zack walks over to see them, Raj introduces Claire as his friend. Zack asks if she’s seeing anyone, so Raj points out she’s seeing him. Zack is confused why Raj described her as a friend, arguing she seems great and wondering why Raj is being casual with her.

As they use the men’s room, Leonard and Howard are still concerned about the potential military application of their guidance system. Leonard wonders whether they should take a step back with the guidance system, but Howard points out he needs more money with a child on the way. Leonard doesn’t see what use money is if they accidentally bring about armageddon. Howard can’t imagine their invention will be used to bring about the end of the world.

Back in the apartment, Bernadette is excited as Sheldon takes her through her final battle in the game of Dungeons and Dragons. Bernadette admits the night has been much more fun than she expected. She thanks Sheldon for the evening, admitting that ever since she got pregnant she feels like she became “pregnant Bernadette”. She says it was nice to take a break from that. Sheldon tells her that any time she needs a break from being pregnant, Bernatrix the Warrior Queen will be there waiting.

Raj goes over to Zack’s table to tell him that he’s killing him with Claire. Next to Zack, Raj doesn’t feel so hot. Raj wants Zack to do him a favor and stop talking about how great Claire is.

Back at the group’s table, Claire asks Penny if Raj brings around a lot of girls. Penny deflects the question to Amy, but Leonard jumps in to say Raj is a terrific guy and loyal to a fault. When Raj and Zack return to the table, Zack loudly says he sees what Raj is saying and Claire is not so great. After Raj asks what they were talking about, Claire says his friends were telling her about all the girls he’s dating. Raj is upset and asks why they would do that when he specifically asked them not to. His friends point out they didn’t reveal how many women he is dating, he just did. Zack wonders if any of them are smart.

The next morning, Leonard is feeling the effect of the night’s drinking when he goes to the kitchen where Sheldon is eating toast. When Leonard asks Sheldon if he ever thought about the military applications of their guidance system, Sheldon answers of course. It bothered him at first but he talked it through with his online friends, Frank and Alicia, and they helped put things into perspective.