Springbank 12 100 Proof
You have a gem. This particular bottling of Springbank is HIGHLY, HIGHLY collectible. It originally **** for $50.00 a bottle and was released in a limited edition. I purchased three of these when they were released ~10 years ago, if my memory serves me right.
The unique quality about this bottling of 100 proof Springbank is not that it is 50% ABV, but that the ABV was achieved NOT by diluting down from cask strength with water, but was lowered by using Springbank whiskies from 12 to 25 years old. In Europe the Springbank 100 counterpart was released as SPRINGBANK 100 British Proof which is 57% ABV. Whereas %ABV in America is half of the Proof, the European proof is British Proof. British proof is calculated by multiplying the proof ( 100 ) by 4 and then dividing 400 by 7 to get the 57% ABV.
Since you are new to Scotch, even though this Springbank has other Springbank whiskies of different ages in it, it is still a single malt; because single malt means whisky from a SINGLE DISTILLERY. Although it has Springbanks up to 25-years-old, it is considered a 12 year old under British law. The same rule applies to single malts as it does to blended Scotches.
Keep these bottles and buy all you can get, but don't let the shop know what they have. Once in a while we all run across a gem. It's by luck. Enjoy!!