This single malt is at the heart of the Johnnie Walker Black blend, however I will not hold that against Mortlach.  In fact I think it is a great pity we don't see more of this single malt (and less Johnnie Walker Black perhaps?).  This bottle comes from refill sherry casks and there are lots of raisin and grapey notes in the nose.  The nose is actually quite intense but very delicious.  The taste is also rich and mouth coating, more darks fruits and classic Christmas spice notes you would expect from a sherry casked Speyside single malt.  Some leather and tobacco as well in the finish which for me is little too dry and could have used something sweet in the taste to balance out and potentially elevate it from a really good to a great whisky.  Nice after dinner dram.