R.D. stands for 'récemment dégorgé' or 'recently disgorged'. What this means is that it has been ageing on its lees (dead yeast cells) in the bottle from the vintage until very recently - around 15 years in this case - which means that it is extra bready, rich and yeasty. It's a pinot noir heavy blend, around 70%, with the rest made up from chardonnay all from the superlative 2008 vintage. This is already being touted as one of the finest Bollinger releases of recent years. It's superb now but will age for 20 years or more if you keep it somewhere cool and dark.
Tasting Note by The Chaps at Master of Malt
On the nose you'll find stewed peaches, honey and rich bready notes while in the mouth there's fresh apricots and apples with an incredibly long nutty finish.