Welcome to August, and what could be more delicious in any weather than a glass of artisanal Beaujolais? One of the most delightful changes I have witnessed in the last few years in wine is the transformation of the average quality of the world's most eloquent expressions of the Gamay grape.   Gone, largely, are those formulaic yeasts and high-speed fermentations that made Beaujolais taste of rubber, bananas and boiled sweets. Today's wines are varied with some verging more towards a red burgundy, some very (sometimes too) obviously oaked, some wonderfully confident and silky in texture – all of them hugely...