How does a Connoisseur/Connaisseuse exactly get ranked up?

[Appletree]

You know, ever since Burgundy appeared, she hasn't ranked up...at all.

And that made me wonder: how exactly does a Connoisseur/Connaisseuse rank up?

 

[Adil]

As seen in one of the early BW episodes, they have something like "connoisseur test" (not an official term) after which they get qualified. But yeah, I would love to see the process in one of the future episodes.

 

[Garren]

Probably a test and an examination, considering in real life that's how Sommelier's receive their title.

I still hope the Pinot Noir/Taverne episode sets-up a Sommelier Society Arc where it's revealed that the society has become so stuck up they consider their word above everyone else's, and Pinot Noir, after Cilan defeats him, is not upset at his loss, but rather him allowing Momotchi (COTD) to choose her own Pokemon despite his advice. He hobbles off to the Sommelier Society to have Cilan audited, as he has disgraced the title of Sommelier. Enter the Four Sommelier Kings.

But of course when Burgundy comes back with a new diploma she'll simply have more food metaphors under her belt.

 

[Likeitornot.]

Yeah, as the others have already stated, they go through exams in order to increase in their ranks.
From Cabernet's flashback in BW019, it seems that the Sommeliers have an evaluation of an individual Pokemon, proceeded by a theory/written exam. However, I'm not sure if this is the entire prodecure, it's not really discussed, and it can only apply to an exam into a C-Class rank for definite, as it briefly displays Cabernet going through the journey of doing and passing the exam.
In BW070, it is implied they must attend classes first before moving up a rank, as Cabernet blames the fact that she's still a C-Class on her absence in the classes due to her battling instead.

 

[Winterdaze]

By purchasing a bigger thesaurus
It seems by attending classes and taking tests, at least for the lower ranks. I suspect higher ranks may have to have some kind of "work experience" period where they have to go and assess Pokemon in the real world. I wouldn't be surprised if they had to do some kind of internship thing. IDK

 

[Almonds]

I think Cilan mentioned about examinations or so. Maybe experiences count as well.

 

[Chao]

I can see an oral examination were the sommelier would judge the compatibility of the trainer and Pokemon. The criteria in ranking would be based on the eloquence and accuracy of their evaluation. As you can see, Dent's evaluation is more eloquent when compared to Cabernet's, which justifies their ranking.

 

[Peppermint Phoenix]

I remember Cilan saying even the C rank tests are very difficult implying that the whole thing is entirely test based. Maybe with a prerequisite like an intership or a class. But what could actually be on these tests? Well to answer that I would need psychology knowledge.

But Imagine most test question would be hypothetical situation between pokemon and trainer and to find the solution with an essay on compatibilty