Like the film Groundhog Day, except Bill Murray at least knew he was stuck.

Then my daughter was born, and the days started showing me their seams. One hour I was a father, holding an infant who has no opinion whatsoever about my inbox. The next I was at a laptop trying to think in straight lines. Then a son. Then a husband. Then, briefly, just a person who wanted twenty minutes that belonged to nobody.

Nobody gives you a moment between those. You are expected to simply switch, so you don't. You carry the last hour into the next one and end up half-present in both.

I didn't need more energy. I needed somewhere to put the last hour down before picking up the next one.

It started with rain

That April it rained properly for the first time in months. I stepped outside and the smell of wet earth put me, without asking, in a courtyard I had not stood in for twenty-five years. Nothing moves you between states faster than smell. Not caffeine, not a to-do list. Aroma arrives before thought does.

So I stopped reading about coffee and started reading about perfume, to find out whether a cup could be built the same way: a beginning, a middle and an after.

But you cannot drink a smell. The coffee still had to be good, and good coffee in India usually means a café, a queue and four hundred rupees, or a shelf of equipment you will use twice. So the format became part of the design. Two sachets, hot water, three minutes.

A kitchen counter and a great deal of bad coffee

All of it happens at a kitchen counter in North India: a hand grinder, a 0.1-gram scale, and a notebook that no longer closes properly.

Mostly it has been failure. Cardamom that vanished into milk, then cardamom that turned the whole cup into chai. Sachets that leaked. Cups my wife described, with devastating economy, as plain. Once, memorably, as half-cooked.

Then one May morning she tasted the cup and, from the other side of the kitchen, said the word cardamom out loud. Nobody had asked her what was in it. That was the first cup that worked.

The failures are all in the Lab, with the verdicts intact.