Allt-a-Bhainne 23 Years Old 1991 (Signatory Cask Strength Collection)

Distilled in 1991 and bottled by Signatory Vintage in 2015 under the Cask Strength Collection imprint, this is a 23 Years Old Allt-a-Bhainne at 55.3% ABV from ex Bourbon maturation. The release is one of 225 bottles and is a sister selection to the earlier 19 Years Old and 22 Years Old bottlings Signatory drew from the same vintage.

Allt-a-Bhainne ferments malted barley for 48 to 50 hours on Mauri liquid yeast in closed stainless steel washbacks, then double distills through two copper wash stills and two copper spirit stills with steam heating and shell and tube condensers. The short Speyside ferment produces a clean malt forward spirit built as a blend filler for Chivas Regal, Passport and 100 Pipers. New make is reduced with Rowantree Burn water and tankered to Keith for cask filling and maturation, since the distillery holds no warehousing on site.

Ex Bourbon American oak frames cask contribution on vanillin and oak lactones from the toasted and charred staves, with Maillard chemistry from hemicellulose oak sugars driving honey and vanilla. The clean American oak palette suits Allt-a-Bhainne's lighter blend filler spirit. Twenty three years of dunnage maturation in the Keith warehouses extends the ex Bourbon contribution into deep maturity, with the slower Maillard products of toasted oak sugars building extended honey and developed lactone structure.