Craft Ginger Ale, with its more intense flavors, works best for this cocktail. Spiced Simple SyrupThe simple syrup recipe makes enough syrup for about 3 Moscow mules. If you anticipate needing more, use a sugar to water ratio of 1:1, and additional spices for each cup of water you add to the mix. (i.e., A triple batch would have 1½ cups each sugar and water, plus 2 cinnamon sticks, 2 star anise, 2 inches of ginger, etc.)Simple syrup will keep up to three weeks in the refrigerator.