Just before setting off for the US I took part in a blind tasting of six extremely luxurious champagnes designed to see whether 50-odd of us could tell the difference blind between the same wine in bottle and magnum (and jeroboam in the case of Krug 1998). It was all great fun, as you can see from this picture taken by Matt Martin.
In very broad outline, the most interesting conclusion was that the majority of tasters did identify the magnums in more cases than not, but ended up actually preferring the wine in the regular bottle size. Only in...