Who, when and why
For anyone who tastes several whiskies side by side, from beginner to connoisseur. By covering the glass for a moment, you will still pick up every nuance you noticed earlier when you return to it. You notice the difference most with fruity, delicate whiskies from the Smooth & Fruity quadrant of the M4W Flavour Compass, whose aroma fades quickly. A small extra to give with a Glencairn glass.