It’s risky to make a film with only three characters. If the audience dislikes even one of them, that’s 33 percent of the ensemble gone. In the case of “Yeast,” a three-person mumblecore debacle by Mary Bronstein, I hate all three of them. How am I supposed to enjoy a film when I dislike 100 percent of the characters?

Something tells me Bronstein would be pleased by this reaction, and part of me admires the chutzpah required to make a film so blatantly cringe-inducing. The wife of Ronald Bronstein, whose similarly aggravating “Frownland” is currently making the rounds, Mary Bronstein has achieved something notable with “Yeast.” It’s a sort of litmus test: Whichever character you hate the most says something about you.

Bronstein herself plays Rachel, a rather bossy, frequently exasperated young woman who has for some reason surrounded herself with friends who do nothing but annoy her. She and her best friend and roommate Alice (Amy Judd) are supposed to go camping with a third friend, Gen (Greta Gerwig), but Alice decides at the last minute not to join them. She refuses to say why, or to even get out of bed. Rachel gets fed up and leaves without her.

The camping trip is a nightmare of awkwardness and irritation. Gen is flighty, silly, immature, and irresponsible. Her cloying behavior is cute, but come on — it gets old after a few minutes, let alone after an entire weekend. How could anyone be expected to endure her on a regular basis if this is how she always is?

For the first hour of the film, I was on Rachel’s side. I pitied her for being stuck in a world that she’s not loose enough to enjoy. This society of hipsters and slackers and devil-may-care attitudes is no place for a serious, mature woman like her. She needs to get away from her “artist” (i.e., unemployed) friends and find some bankers or stockbrokers or something.

It seems to me that her behavior shifts in the last 20 minutes, though. She becomes outrageously bitchy and controlling, far more than is justified by her friends’ maddening inertia. I went from sympathizing with her and hating the other two to hating all three of them. They all infuriate me beyond measure.

Yet I see that other viewers have had sort of the opposite reaction: Gen and Alice are fine; it’s Rachel who’s awful. Cinematical’s Kim Voynar wrote that Rachel is “a maddeningly annoying control-freak dealing with her fractured relationships with two friends.” Spout’s Karina Longworth calls Rachel “a torturously needy, bullying, self-obsessed adult-age girl who comes to learn the hard way that she is not the center of the universe.” At Salon, Andrew O’Hehir says she’s “a monstrous and manipulative young woman, simultaneously cruel and needy, who abuses and berates her roommate and her supposed best friend without mercy and then can’t understand why they’ll do anything to get away from her.” This is Rachel we’re talking about — the one I sympathized with for two-thirds of the movie.

Hmm. I don’t like to contemplate what this says about me. But truly, I couldn’t stand Gen — and I adore Greta Gerwig, who plays her! That’s a testament to Gerwig’s skill, I suppose, that she could create a character so slap-worthy despite her own charming cuteness. And Alice is just sluggish and lethargic and slovenly and useless. Ugh.

So the film has value as a divisive conversation-starter and character study, perhaps, and maybe it was Bronstein’s intention to make it so grating and tiresome as to be virtually unwatchable. But I’m not sure doing it on purpose makes it OK. If you want to make a movie to help you work through your own issues, fine — make the movie and show it to your therapist. Don’t expect us to congratulate you for doing a great job of making something unbearable.

D (1 hr., 18 min.; Not Rated, probably R for abundant harsh profanity, brief partial nudity.)