A lot has already been said and written about non-sulphured wines (put 'natural wine' in our search box, for instance) but the topic remains highly fashionable, as witness this year's RAW wine fair in London six weeks ago. In its catalogue, the organiser Isabelle Legeron MW made a point of publishing the exact level (or absence) of sulphur in each and every wine the participating producers showed at the event. She leaves no stone unturned when it comes to touting the benefits of sulphur-free wines while trying to convince the stubborn among us that these wines can age – presumably...