Whisky Glenfiddich 19 Year Old Age of Discovery Maderia Cask Finish. In homage to the intrepid Portuguese voyagers who went on to change our understanding of the new world, we created Glenfiddichs first ever 19 Year Old single malt Scotch whisky. Finished in fine, aged Madeira wine casks from an independent island winery dating back to 1850 we named this expression, Glenfiddich Age of Discovery. An earthy, bright whisky with a warmth that fades to long sweetness. The first time we’ve used Madeira casks for incredible, rich depth.