By Harold McGee
Spirits are served at temperatures ranging from ice cold (Swedish aquavit) to steaming hot (Calvados). To appreciate nuances of flavor, they’re best served at room temperature, and if necessary warmed in the hands. Their aroma is intense, so much so that it can be just as enjoyable to sniff as to sip; Scotch lovers call this nosing. At distilled strengths, alcohol has an irritating and then numbing effect on the nose that is accentuated at high temperatures. To reduce the interference of alcohol and bring out more delicate aromas, connoisseurs often dilute whiskies with good-quality water to 30% or 20% alcohol. Different kinds of spirits have very different flavors, which derive from the original ingredient—grape or grain—from the yeasts and fermentation, from the prolonged heat of distillation, and from contact with wood and the passage of time. Spirits with a high fusel oil content have an unctuous quality in the mouth, while more neutral spirits give a cleansing, drying effect. The aromas of spirits often persist in the mouth long after the liquid itself has been swallowed.