Eggnog can be a pretty simple mixture of dairy and booze, but it’s the extra ingredients that make it pop. These ingredients, usually spices like nutmeg, cinnamon, and vanilla, give the drink extra layers of flavor, stopping it from being too cloying.
How you use these flavorings, though, will make a big impact on how good they taste. If you just decide to dash them in at the end, they won’t distribute properly and will instead provide a taste that is too harsh, raw, and inconsistent. To get around this, do what Gordon Ramsay does and allow your spices to infuse in your milk, making it the first job that you do. Ramsay mixes his ground spices into whole milk using cinnamon, cloves, nutmeg, and ginger, as well as a few dashes of vanilla extract. After heating the mixture just to the boil, he then allows it to cool and infuse for ten minutes.
This infusion process essentially serves to activate, extract, and distribute the flavors of the spices. It also develops their flavors, unlocking their full potential for the drink. By resisting the urge to boil them for longer, you also don’t kill off any of the taste of the spices.