Method: Place sugar cube in base of mixing glass and soak with bitters and a small dash of soda water then muddle into paste. It’s OK if the sugar isn’t completely dissolved, a little sweet crunch can be nice. Then pour whisky into mixing glass and fill 3/4 with hard ice. Stir about 18 to 20 times. Strain over one large cube of ice in an Old-Fashioned glass. Squeeze an orange zest across the drink to release the oils, give it a twist and drop it in the drink.