For those of us who are addicted, coffee has mystical powers. Caffeine is a drug, of course, but beyond the natural high, the aroma and the taste, its café-culture associations have lately made the daily cup iconic. In part, this is thanks to brilliant marketing that makes believe that for two quid a shot we can all be bons viveurs and transfigure our daily grind through what we drink.

However, now two British film-makers have harnessed coffee’s cachet for more altruistic ends, in a powerful documentary, just released in this country, called Black Gold. Nick and Marc Francis want to connect consumers not with the aspirational world of the marketers but with the reality of the people who actually cultivate the stuff, particularly in Ethiopia. The fact is that, while we are swallowing the dream, they are often left with little but the bitter taste of dregs.

‘Ethiopia produces some of the best coffee in the world, yet those coffee-growing communities are now caught up in a food crisis,’ Marc explained when I interviewed him recently for Developments magazine. ‘The industry has grown to $80 billion a year, coffee shops are opening on every street corner, and yet coffee farmers are struggling to feed their children. That’s outrageous and insane.’

His brother continued: ‘We wanted urgently to remind audiences that through one cup of coffee they are inextricably connected to the livelihoods of millions of people around the world who are struggling to survive.’

Their film follows the work of one man, Tadesse Meskela, whose co-operative union represents over 74,000 Ethiopian coffee farmers in the fight for a better price. Growers receive around 23 cents per kilo of coffee, yet every kilo yields 80 cups – with an average retail price of $2.90. Black Gold challenges the big five buyers – Kraft, Nestlé, Procter & Gamble, Sara Lee and Starbucks – to wipe the stains of injustice from their business.

And what of us, the consumers? Is it enough to savour the aroma of our cup of fair-trade and feel good about life? Perhaps we need to wake up to the smell of death that still hangs around a grossly unfair trade. In the global village, we are all neighbours now. If we’re to be ‘the fragrance of life’, as Paul calls us in 2 Corinthians 2.16, this film could help us – even if it makes us choke on our skinny cappuccinos.