You need only walk past here to sense the seriousness of purpose at Base Camp. There’s Mr Tezuka, unsmiling in the window. Running his machines. Few customers at the tables out the back. The shopping street, Satake Shotengai, near-deserted.

You never go in. Maybe it seems like a place for drip-coffee maniacs.

But today is cold and windy, and you’ve been walking 20 minutes from Kaminarimon. So, you ask for a seat. The first thing you discover is, Base Camp is not even a cafe.

Mr Tezuka’s wife says, The tables are only for customers who buy our beans. You get a free cup while you wait for us to roast them.

Base Camp is not cheap, but you believe Mrs Tezuka when she says you’ll pay far more for this quality elsewhere. We bring in the best beans, but hold down our prices for the neighbourhood, she says, gesturing toward the empty street.

The care extends to the service. Mr Tezuka writes down customers’ names in a little book, along with their preferred beans and roast. The next time you come, he looks you up.

His roasting machines are small revolving drums fixed to the top of gas rings. They are made in Niigata. As far as you can tell, apart from the gas control, they have only an on-off switch, meaning the adjustments are all up to Mr Tezuka. Experience must count for a lot in this job, to know when a roast is done, to know when to stop.

He enquires what you’re after. You tell him, something to drink black, stovetop espresso. There are so many options, he says. Starting with the raw beans. Then we have five roasts, from Medium through City to French.

He recommends the house Oedo Blend, French roast.

Take a seat at the back. Mrs Tezuka brings coffee. The kero heater blazes. The beans rattle away, like beads in a jar. Posters from a coffee calendar are framed on the wall. Mr Tezuka tells you he used to be a mountain climber. That’s how the place got its name. Now you hear him put the beans through a new-model grinder. The powder is finer than the coffee any other roaster has given you. Mrs T. instructs you to keep it in the freezer.

At home you can’t stop drinking it. It is exquisitely bitter and crisp, no lingering aftertaste, no burnt notes, no jitters. Summit achieved.

Base Camp is at 3-2-11 Taito, Taito-ku tel/fax 03-3831-0613