I HAD been out partying after a wine tasting in London, and caught the last Tube back to my brother’s place where I was staying. Cocooned in a warm carriage I was soon fast asleep and remained so until we juddered to a final stop on the far side of the Circle Line.

Sitting on the night bus after an hour’s wait in the rain should have been the moment to make creative connections between booze and the underground. Instead I sat cursing my fate and left it to Nikki Welch to dream up the wine Tube map.

It is a brilliantly simple idea based around 54 styles, regions and grape varieties that act as stations. The logic goes like this: rather than sit for ever at sauvignon central, for example, why not branch out? You could take the aromatic line to albarino and riesling, or head west to semillon and vinho verde.

I met Welch in Edinburgh where she lives after 13 years at Thierry’s, a big wine importer in England. It seems there wasn’t a eureka moment on the Piccadilly line or even a night bus, but rather a growing frustration with the trade’s failure to engage consumers with its highfalutin vocabulary.

With lines of bottles decorated with Post-it notes, she assembled the various lines and sketched out her first map in 2011. “It was about trying to make connections and make wine explorable,” she explained. “The practical advice people really wanted was simply: ‘If you liked that, try this.'”

Her idea has since evolved into The Pocket Wine Guide (Birlinn £7.99), and will soon become an app.

Of course the wine Tube map only takes you so far, but it would help anyone navigate their way into the subject. In the supermarket faced with a wall of wine like paint in B&Q and with nobody to ask, it’s unsurprising if people are confused. Three years ago, having surveyed 2,000 shoppers, Morrisons claimed only 26 per cent of us have faith in our wine-buying decisions.

I blame those endless dodgy deals that dictate the way we shop. Prices ping up and down with little if any regard to value, and most promotions are smoke and mirrors, especially if they shout "half-price". The only way out of this promotional loop that accounts for more than two-thirds of wine sales is to acquire a little knowledge, and perhaps a map.