Over-Hyped

We had a bottle of prosecco that I ordered from Green & Blue, and it was so non-descript, so ho-hum, that I actually had to go back to their website to see what it was that attracted me. What they said about the Casa Coste Piane Valdobbiadene Prosecco was that the producers are meticulous about their fruit (so far, so good), that it is bone dry and full of mineral and restrained fruit (yes on the dry, restrained on the flavour), and "it would be a crime against all the Gods of Wine if you don’t try it at least once". Here's where they've gone too far for me, because this wine wasn't all that. It was almost completely flat (the bottle does say 'Frizzante...Naturalmente', so I was not expecting to be wow'ed by the bubbles) and no more special than any other prosecco that I drink by the glass when I'm out at a pub or at Borough Market. I found it disappointing - it was an OK wine, nothing horrible about it, but nothing that remarkable, either. I'm surprised by the rave review, which is echoed on some other websites.