By Libby Brodie This is the summer of sake in London – and about time too. I had been under the misguided impression that all sake was rough and intensely boozy, the type of drink one hocks back as a dare. However, despite a fairly high alcohol percentage, sake is relatively low in acidity and has a graceful softness when sipped. It is a delightful revelation. Kioku Bar in The OWO is a relaxed and welcoming spot of warm honey-coloured wood, designed in the style of a traditional Japanese listening bar, where drinks are served to a sound track. Indeed, Sommelier Anthony Yukio was as attentive t…