‘Sauvignon Blanc smells like cat pee,” a wine-tasting expert tells us in the amusing and suspenseful documentary “Somm.” So “we use the word ‘blackcurrant bud.’ That’s kind of our code word.”

Such unexpected moments of pomposity deflation make this film a delicious tipple as it follows four friends through the exacting preparations for the test to become a master sommelier. Imagine an exponentially more difficult bar exam, one that produced just 197 practicing lawyers worldwide.

Jason Wise’s entertaining and enlightening film does suffer from a somewhat obtrusive score, from a coyness about who the contestants are when they aren’t sipping wine and from lack of access to the climactic test (though Wise does deliver some brilliant moments in filming the winners and losers as they learn their results).

Yet “Somm” does a fairly impressive job of making wine tasting somewhat cinematic despite its being essentially unfilmable, at least until taste-o-vision comes along. And it’s reassuring to learn that the subject is so vast (Italy alone is home to some 3,000 kinds of grapes) that some of wine’s most ardent students are virtually dipping their stemware into the ocean. “The reality,” says one sommelier about a blind tasting, “is that you have no clue what the wines are.”