It is a bewitching thing, coffee. For years I used to follow the daily twists and turns of the London coffee market, reporting on the tremendous Brazilian frost in July 1975 which devastated the crop and caused world coffee prices to triple in the two subsequent years.

I remember the dark auction room in the Brazilian port of Santos where the traders met to spar over the latest market offerings before retreating to their dusty offices to taste and sniff the export crop.

I remember the not very interesting coffee I had years later in Saigon, after the United Nations taught an emerging Vietnam how to grow coffee and their exports were soon equalling the global oversupply of beans on the world market, depressing prices for growers everywhere.

When coffee-growing nations met to try to agree on export quotas to keep prices from falling, I remember the exquisite coffee they used to serve at the International Coffee Organization, a sort of OPEC for coffee-growing nations with its headquarters just round the corner from the BBC's Broadcasting House in London.

I remember the terrific coffee I drank in Rwanda where they were trying to tell the world about its surprising quality grown in a scarred country, haunted by genocide.

I remember the superb brew served in Singapore in a cafe where they dripped melting ice cubes over the ground coffee to produce a concentrated liquor which is then diluted with hot water. Takes 12 hours, tastes terrific.

Image copyright Getty Images Image caption A civet with coffee berries

I remember the very special indeed Kopi Luwak served in Jakarta. The coffee berries are eaten by civets, and processed in the digestive tract of the animal.

Find out more Listen to From Our Own Correspondent for insight and analysis from BBC journalists, correspondents and writers from around the world Broadcast on Radio 4 on Saturdays at 11:30 BST and BBC World Service Listen to the programme Download the programme

When the beans are (so to speak) spat out at the other end, they are collected and sold at very high prices. The coffee was interesting but not exquisite. The practice has led to charges of cruelty as demand for this curious Indonesian novelty increases.

And demand is growing, for coffee everywhere. It's said to be the developing world's second most valuable traded commodity, outstripped only by oil.

Now what occasioned this stream of semi-consciousness was an encounter the other day with perhaps the most delicious cup of coffee I have ever drunk. Like Marcel Proust tasting that little cake, the Madeleine, my cup of Finca la Soledad Urrao brought it all back.

I happened to be in the city of Medellin in the hills of Colombia, the third largest coffee exporting nation in the world. Medellin is Colombia's second biggest city, but in recent decades it's been better known worldwide for its exports of another stimulant, cocaine.

In 1991 Medellin was the most violent city on earth, with more than 6,300 murders as gangs fought over urban territory.

But a long government war on the drug lords brought them down, the gangs retreated, the murder rate settled down. Medellin's mayors engaged in a comprehensive programme of urban renewal - a new metro and cable cars to bring in slum dwellers trapped in distant poverty, striking new parks and civic buildings - cultivating new, and tangible, city pride.

So I thought about all this as I looked out over a plaza in Medellin the other day lined by 23 huge black sculptures by the locally-born Fernando Botero, now the country's most celebrated artist. His hugely distinctive people look as though they are wearing fat suits, trapped in ballooning corpulence. He's given many paintings and sculptures to his home of Medellin, and they are unforgettable.

Image copyright AFP

Just like the coffee I was sipping as I looked out over Botero Plaza from the cafe called El Laboratorio de Cafe, the Coffee Laboratory, where they serve what is said to be some of the finest brews in this famed coffee region. Though brew is the wrong word.

A precise barista weighed out the beans, from a named finca, or estate, in the regional hills. She ground them not too fine, and then decanted them in a filter.

Using water at 90C, certainly not boiling, she poured it out in tiny amounts from a thin-stemmed kettle over the coffee, waiting for it to pass into the glass pot before adding a little bit more.

And then the savouring as it was poured into the cup. The smell. The taste. No milk, no sugar, no need. It was delicious, quite delicious.

A sudden rainstorm broke over this city of perpetual spring, as the Colombians call it. And decades of coffee memories came flooding back, as I lingered over one of the coffee-est moments I have ever experienced.

Image caption Weighing the beans - the first step to the perfect coffee

Image caption The water is heated to 90C (194F)...

Image caption ... and poured - a tiny amount at a time - over the coarsely ground beans

How to listen to From Our Own Correspondent:

BBC Radio 4: Saturdays at 11:30 BST

Listen online or download the podcast.

BBC World Service: At weekends - see World Service programme schedule or listen online.

Subscribe to the BBC News Magazine's email newsletter to get articles sent to your inbox.