Like a bare tree in winter, some winter drinks are meant to be austere: dry, direct, bracing, with the sort of thrust that allows its effects to make a beeline to the belly. Certainly that's true with your basic shot, whether tequila or scotch or bourbon, but not everyone is interested in slamming such spirits; and to 'do' a shot as such is no way to administer a slow burn.
In southern California the solution, so to speak, is found in a winter fruit, for a simple cocktail called the Scotch & Lime. Few drinks can boast of its bracing, lipsmacking directness, a kind of linear mouthwatering pleasure that acts like medicine without being medicinal, that warms the belly while offering a surprising amount of complexity — scotch, in high citrusy relief. The drink is sour, but it's not a sour, per se, neither a whisky sour nor a scotch sour — both would call for a touch of simple syrup to ameliorate the tart and the heat — but this is one that should simply be left untamed.
According to drinks columnist and mixologist David Wondrich, proportion is everything in a drink like this. Too much lime and the drink becomes merely tart at the expense of the scotch. Not enough, and you may as well just have a scotch. He's arrived at a ratio of 3 ounces of (blended) scotch, on the rocks, with one-half ounce of lime juice, the lime working like a snakebite to almost clarify the flavors of the spirit, brightening the drink without taking away too much of its sensation as it hits the spot — like medicine taking effect, delivering the warm punch you're looking for.
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