I used a cheap Islay single malt (probably Laphroaig) as the Scotch for fun, added two dashes of bitters for balance, and stirred it for long time. To let all the ingredients come together in balance, I need to get enough dilution. So as written in the recipe, you either need to add some water in advance, or stir it over one minutes like I did. In the end, I’d say it's a really good cocktail.