William Grant & Sons has unveiled the fourth batch in its The Balvenie Tun 1509 series – an expression consisting of liquid from 23 different casks.Following the release of the first, second and third batches of The Balvenie Tun 1509, the fourth batch in the range has been hand-selected by The Balvenie malt master David Stewart. Stewart selected 23 whisky casks and Sherry butts from the distillery's aged stocks. Each liquid was then put into the tun marrying vessel. The whisky was left to marry for several months before being taken to the distillery for bottling. The marrying process allows for elements of all 23 whiskies to blend together, resulting in a "unique" single malt. On the nose, scents include "sweet toffee vanilla fudge, honeycomb and oak spices". Tasting notes suggest that "the initial sweetness gradually develops into deeper richer oak with some dried fruits and a cinnamon and ginger spiciness". Stewart said: "Stock management is a unique and enjoyable part of my job as malt master and Tun 1509 Batch 4 is a perfect example of how marrying together various individual casks can create an expression of real quality. "I’ve been delighted by the response of the whisky community to previous batches and I’m sure Batch 4 will be as highly regarded." The expression is bottled at 51.7% abv, and has an RRP of £220 (US$289.99). Earlier this week, The Balvenie launched their oldest expression as part of the brand's DCS Compendium Chapter 3 – a 55-year-old single malt whisky.