From Requiem for a Margarita.

1/2 ounce of Triple Sec (1 tablespoon)
1 ounce of fresh lime juice
1 1/2 ounces of light tequila

Making the best margarita in town—at home—is not a matter of money. It does not depend on buying the best tequila or substituting classy Cointreau for the cheaper Triple Sec. No, the one most important thing is to use freshly squeezed lime juice. If you don’t do that, no amount of expensive ingredients or fancy recipes will ever make it more than mediocre.

The formula we have settled on comes from The Cuisines of Mexico by Diana Kennedy. It is deceptively simple and deceptively strong. It is also quite small, because a classic margarita is a drink that you sip, like a liqueur or fine Scotch, not one that you chugalug.

Begin by chilling a cocktail or martini glass. It is important to use a glass with a stem, so the heat from your hand does not warm the drink. Don’t use a wine glass; the inward curving rim will keep you from getting the full effect of the salt around the edge. Rub the rim of the glass with a cut lime, put some salt on a plate, and lightly press the rim into it, so that it is coated, but not caked.

For each margarita combine 1/2 ounce of Triple Sec (1 tablespoon), 1 ounce of fresh lime juice, and 1 1/2 ounces of light tequila. (There is no point in using naturally aged gold tequila because its sublime flavor would be masked by all the other ingredients.) Shake the liquid with ice cubes in a cocktail shaker and strain it into the glass. Don’t include the ice or your drink will be too watery.

Now taste. That is a margarita. It doesn’t taste like what you’re used to? Well, we can’t help it if your taste buds have been corrupted. If you insist on adulterating your drink, we can’t stop you, but we can at least give you some acceptable pointers.

You may reduce the tequila to one ounce if you don’t care for its strong, distinctive flavor. You may sweeten the drink by using equal parts of Triple Sec and lime juice, or add sugar (start with 1/2 teaspoon) if you don’t want more of the strongly distilled, acidic flavor of the Triple Sec. The one thing you must not do, under any circumstances, is combine the ingredients with ice and mix them to slush in a blender. Anyone who would do that would put tomato juice in his beer or sugar in his coffee or commit other moral outrages too heinous to mention.

What does it cost to make a margarita at home? Our classic, using an inexpensive tequila, costs about 45 cents for a three-ounce drink. A six-ounce size, more nearly what you get in a restaurant, would be 90 cents, but remember—the classic has about twice as much tequila as the norm and restaurants buy their liquor wholesale.