As a barista at Toby’s Estate, Costa Arvanitopoulos noticed a growing trend: customers looking for coffee beans from specialty roasters to brew it at home.

“Talking to hundreds of customers on daily basis, [I found] there was a real need for easy access to quality coffee,” he tells Broadsheet.

Taking inspiration from straight-to-home grocery delivery services, he and his wife Effie stumbled on the idea of an online marketplace for roasted coffee beans, not just from around the country, but also from across the globe.

“Giving everyone access to the best coffee from Australia, as well as Malaysia, America, the UK, and delivered straight to your home – it was a no brainer,” he says.

So became Barker St, a one-stop online shop selling coffee beans. It’s a collaborative effort – Effie deals with strategy and finances (the bean counter if you will), while Costa selects and contacts roasters (the bean courter).

“I know what they do, how they do it and how well they do it”, he says, adding that roasters must use high-quality, ethically sourced coffee beans.

“[Ethical coffee] is so important to me. When it’s not ethically sourced you’re pretty much ripping off the farmer at origin,” he says.

About 40 per cent of Barker St’s brands source their green beans directly from the coffee grower, which ensures a better price for the farmer; the other 60 per cent use a wholesale green-bean buyer with reputable credentials, and can negotiate fair prices with coffee farmers or farming co-ops. In short, he sources from conscientious roasters, and not from “a multinational trying to rip off the farmers”.

Barker St features some familiar Australian coffee-roasting stalwarts. There’s Mecca and Reuben Hills from Sydney, Everyday and Five Senses from Melbourne, and Monastery in Adelaide. Asked, if Australia has such a healthy roasting culture, why bother looking overseas?

“We love Australian roasters but we wanted to give variety. Not many people get to travel to London and New York, and if they do, they don’t know about these roasters,” says Costa.

He’s handpicked an international line-up of well-regarded labels: Onyx Coffee Lab from Arkansas in the US, Nylon from Singapore and Caravan from London. But his biggest boon was getting Denmark’s La Cabra on his books.

“They’re pioneers in the industry, and the CFO is from Australia. They were fantastic – they were the white whale we wanted,” he says.

He also highlights Colonna, the Bath-based roaster founded by three-time UK Barista Champion Maxwell Colonna-Dashwood. “He’s definitely one of the best in Europe,” says Costa.

The UK roaster only offers three small-batch roasts of coffee at a time – an all-rounder, a single origin and an “extremely rare” coffee – and rotates the selection each month.

But picking Costa’s favourite roaster, from here or abroad, is like picking his favourite child – he loves them all. “They all have a special place on the website. I respect them all equally,” he says.