For the unacquainted, shokupan is an incredibly fluffy milk bread that originated in Japan. It’s like Wonder White on steroids, and it’s often used to make katsu sandos.

When Melbourne baker Quentin Berthonneau first tried it, he was “blown away by the texture”.

So much so, the Q le Baker co-owner (who trained at Vue de Monde and Chez Dre) made a side hustle out of it, which launched just before lockdown.

Using a recipe refined over two years and a dozen trials, he’s baking just 30 loaves a week and delivering them across Melbourne. And they’re already so sought-after he’s had to institute a waitlist.

But Berthonneau makes his shokupan a little differently. Where the traditional recipe uses yeast, his unusual riff uses sourdough. “The difference between mine and most others is it’s naturally fermented, and it doesn’t have any additives in it,” he says.

Despite a flurry of wholesale enquiries for his carb-heavy, perfectly rectangular prisms, the 30-a-week limit remains. “I’m not planning to make thousands of shokupan,” says Berthonneau. Instead, he’s doing a series of collaborative pop-ups with venues around town – where you’ll be able to get your hands on his bread, and a one-off creation made with it.

The first is this Sunday at Hibiki, a Japanese-style brunch spot in Camberwell. Owner Reiji Honour will serve hikiniku tamago, a sando with mince-meat-stuffed omelette, cos lettuce and house-pickled daikon radish.

Berthonneau also teases two upcoming collabs – with Richmond sandwich shop Hector’s Deli and North Melbourne bakery Beatrix.

The Shokupan x Hibiki pop-up is on Sunday July 5 from 9am to 3pm at 1161 Toorak Road, Camberwell. Orders for Shokupan can be made via Instagram.