Glenfiddich 18 Year Old Perpetual Collection - Vat 04 Whisky (70cl, 47.8%)

It's the fourth installment of the Glenfiddich Perpetual Collection, originally released as a travel retail exclusive. The collection explores perpetual maturation in a method similar to a sherry solera system, with whisky matured in a series of vats that are never fully emptied. Each vat is only half emptied for bottling, and then topped up with younger spirit so that the maturation continues while retaining a portion of the original spirit. This 18-year-old single malt spent its time in a selection of oloroso sherry and bourbon casks and was married in solera vat number four.