Glenfiddich 15 Year Old Solera Reserve Single Malt Scotch WhiskyGlenfiddich 15 Year Old Solera Reserve single malt Scotch whisky is created using a technique pioneered by our Malt Master and its warm, spicy flavors are transformed with the alchemy of the Solera Vat. Our Solera Fifteen is aged in European oak sherry casks and new oak casks, the whisky is mellowed in our unique Solera Vat, a large oak tun inspired by the sherry bodegas of Spain and Portugal. Never emptied, and kept half full of whiskies since 1998.