*Sour has a more plain and casual look, she has a full purple medium-length hairstyle with purple eyes and no head accessories on. Her skin is a bit purplish. She wears a white short-sleeved t-shirt, a purple plaid skirt, pastel purple tights, violet flats, and what seems to be a lace choker. She has a minimalist and emo fashion style instead of her former punk and neon style.

In summer episodes, Sour wears a white sleeveless summer dress over a purple shirt/shorts, with a dark purple sash belt tied in a bow, and purple flats with light purple bows on the toes.

In winter episodes, Sour retains her usual clothes but wears a white beret, a white winter coat with purple outlines, and a light purple scarf over it.

Sour Grapes is very unemotive and quiet, rarely showing any emotion outside of deadpan apathy. Like her best friend Raspberry Tart, she seemed to have a bit of a mean streak, though not to the same extent as Raspberry, at worst being judgemental over Strawberry's outfit being "matchy-matchy" in Mean Berries. Sour Grapes' closed-off nature also means she doesn't like being the center of attention and is easily overwhelmed, such as in Sweet and Sour when Strawberry tried to befriend her in her usual outgoing extroverted way, which just served to turn Sour away. It's also why she's much more willing to listen to Lemon Meringue, who relates to Sour's introverted personality and was able to connect with her on a deeper level.

A recurring theme with her is just going along with what others tell her to do, like being Raspberry's minion or working with the Pieman. While she helps Raspberry and Bread Pudding in their schemes, she doesn't really show all that much investment in it, and only goes along with their plans because of their friendship. In general, she didn't really seem to have the same level of animosity that her friends had with the Berry Besties. In stark contrast to when she worked for Raspberry, Sour Grapes was much more hesitant to do what Pieman said, but she still followed his orders despite his mistreatment because he was family. Sweet and Sour eventually showed that despite her unemotive personality, she hated working for Pieman and felt sad over how lonely she is, not being able to open up to berries who cared about her. Fortunately, Strawberry overheard her and made an effort to help reconnect her friendship with the Berry Besties, helping Sour realize that she shouldn't have to put up with Pieman just because he's her uncle. Afterward, she stood up for herself and refused to be pushed around by Pieman anymore, quitting working for him to be with the Berry Besties, who she now sees as her true family.

While she is generally apathetic, she does have a lot of things she likes to do. In Strawberry Surprise and Crushing The Cosplay, she's shown to enjoy drawing, and the massive change from the former episode's simple sketch to the latter's incredibly detailed drawing indicates she draws incredibly frequently. In the latter episode, it's also revealed that she's a massive fan of Tangerine Smash and Guava Girl, and has an encyclopedic knowledge of the entire franchise only rivaled by Orange Blossom. She also likes gothic and creepy things. In "Lemon's Name in Lights" one of the few things she seems happy about is when she got to decorate the Christmas tree in a purple, gothic style with a giant skull on top. Ironically, the Berry Bestie that Sour gets along with the most is Blueberry Muffin, who's bubbly and excitable, but admittedly to a lesser extent than Strawberry. It's suggested she enjoys Blueberry's quirky nature, as she was intrigued by her love of raw marshmallow on s'mores, and went along with Blueberry on her quest to finally meet Cinnamon Swirl despite having no real reason to.*