Hemming, who also writes for Jancis Robinson MW’s Purple Pages, was among 19 new masters of wine joining the institute this year – a record high for the body.
He said: "Passing the MW is such huge a relief, and I've been overwhelmed with messages of congratulation and celebration, which has been lovely. When I started, I had no idea it would take me six years but it has all been worthwhile, and I'm thrilled to have got there in the end."
They also include former Selfridges buyer Dawn Davies, who is joining Speciality Drinks as head buyer, Sarah Knowles, the Wine Society’s buyer for Australia, New Zealand, North America and Austria, and former Harpers journalist Rebecca Gibb.
Masters of Wine go through a rigorous series of exams as well as publishing an in-depth research paper on a wine-related topic.
IMW chief examiner John Hoskins MW said: “Not only do we have a record number of new MWs, but we can report that the general standard of the research papers was considerably higher than equivalent papers submitted in previous years. This is testament not just to the hard work of the candidates involved, but also to the success of the overhaul of the exam process.
“We now have a strong pool of MWs with the experience to give students the guidance they need to tackle this last part of the exam, which for many had in the past proved to be the most frustrating.”