AT a small cafe hidden away off San Francisco's busy Market St, James Freeman is proving that there's no such thing as too technical when it comes to making coffee.

In his Blue Bottle Cafe on Mint St, the counter is dominated by a couple of contraptions that would look more at home in a mad scientists' laboratory, but which actually represent a San Franciscan pursuit for perfect coffee that combines technology and tradition with an astonishing attention to detail.

The New York Times has put the price of Mr Freeman’s dedication to perfect coffee at $20,000 - and that's just for one of the machines.

He says that’s a little overblown, but not by much.

“The $20,000 was basically the machine, the sourcing the beans, the labour – they got it up to that figure,” he said.

“But they’re all pretty expensive, I can say that much.”

His favourite is the copper-clad lever espresso machine, a vintage Italian job from the 1970s.

But for perfect coffee, he says no one does it like the Japanese.

To prove it, two years ago, Mr Freeman sourced a pair of Oji drip-fed machines from Japan, a place where he’s been “pretty much dazzled by everything” since his first visit 26 years ago.

The Oji machines fuse tradition and tech in a way that might seem ridiculous to non-coffee drinkers, but those queued around the block outside his Blue Bottle Café in Mint St give thanks for it twice a day.

Twice a day because, if it’s Blue Bottle’s famous iced coffee from the taller of the two Ojis you’re after, it takes 12 hours to make a pot.

They make two pots overnight ready for the morning crowd and try to turn it around in time for the evening.

Each pot starts with 3.2 litres of water in the top globe, which releases exactly 88 drips per minute through a glass cylinder holding 160g of coffee.

The coffee is “single source” – all the beans are from the same crop, not blended – and coupled with the fact there’s only six litres of it available every 12 hours, chances are that might all add up for the world’s most expensive hangover cure.

“It’s $4 for a 12-ounce glass of ice coffee,” Mr Freeman says.

“It’s a wonderful iced coffee, kind of a bourbon-like iced coffee. It’s got a heat to it that’s like having a shot of bourbon.

“It’s hard to give it away at that price – some of the stuff we do, like the siphon coffee, are a premium service – it’s a pretty good deal.

“We run out a lot.”

In fact, Mr Freeman’s running out more and more.

In March this year, five Oji machines in Blue Bottle Cafes made their debut in Brooklyn.

Then there’s the other Oji - the "$20,000" one that makes hot coffee.

This one is a five-globe affair, arranged horizontally.

While not as slow as its taller counterpart, the brewing process is more spectacular.

Water is heated in each globe by halogen lights, which forces it up into a module holding the coffee grounds.

The mixture is stirred with a bamboo paddle in a manner which has to be perfected by baristas before they get to lay a hand on Mr Freeman's machine.

The "art" is creating a whirlpool within four turns, something which Mr Freeman says he spent months practising.

Stir it too much (more than 90 seconds) and the coffee over-extracts. Too little (less than 45 seconds) and your coffee is underdone.

The mix is then filtered back down into another globe and kept at that temperature by a barista cradling it with a moist cloth.

Although he calls his vintage lever machine his “rosebud”, Mr Freeman said he prefers the routine of making siphon coffee in the morning.

“It’s a very nuanced technique,” he said.

And the chances of Australians ever experiencing an iced coffee that takes 12 hours to brew aren't out of the question. Mr Freeman said it's just a matter of convincing the Japanese suppliers that their machines will be given the dedication they deserve.

“The reason others don’t do it is because it’s expensive and difficult to get right," he said.

“Anyone can buy them if they want.”