Dalwhinnie Winter Gold: why doesn't it freeze?

 

Thanks to Paul for this treat! It is kept in the freezer for 24 hours before serving but doesn't melt. I found a graph of freezing temperature versus % alcohol here and this would need -30 degrees Celsius to freeze, far below any domestic freezer. This has raised a load of questions. Firstly, what is a eutectic point? That's going to need some research. Secondly, what is it about alcohol that means that it has a different freezing point in the first place? More work to be done.