Sour mix is a combination of sugar, water, lemons, and limes. One batch could give you a whole party's worth of margaritas, whiskey sours, or daiquiris without much effort. A bottle of sour mix may call to you from the store shelf with a siren song of good times and an easy-pour spout. Don't be fooled. No one should use store-bought sour mix. Ever. It tastes like cheap lemon-lime candy with Jell-O mix and looks like Gatorade stirred with uranium. The homemade version tastes like fresh, real juice and real sugar, which is what you want in a cocktail.
What's Available to Buy
There are dozens of versions of commercial sour mix available—sometimes called sweet and sour, Margarita, Collins, or lemon-lime mix—and most grocery and liquor stores carry it. Sometimes it comes in a big plastic jug, small artisan-looking bottle, or bag of powder, but however it comes, store-bought sour mix is evil and must be stopped.
Cheap sour mixes are made from artificial lemon and lime flavoring along with corn syrup, coloring, preservatives, and stabilizers. Higher-end mixes are made with juice from concentrate, citric acid, and sugar. Despite its appearance, commercial sour mix is not made with radioactive citrus and will not give you super powers. (Though if it did, you would be able to thwart criminals by shooting a mildly irritating yet pleasant-smelling acid into their eyes.)
The true beauty of making this mix is having a fresh, versatile, and easy cocktail mixer for parties. However, it's also great to have on hand for lazy-night-at-home whiskey sours or an impromptu afternoon margarita with the neighbors.
There's no reason to buy sour mix when in 10 minutes you could hand-make something almost as convenient and infinitely more delicious. You just can't beat real, fresh ingredients. Making your own sour mix isn't an elaborate project. Juicing a few lemons and limes and combining it with sugar water doesn't take a lot of time or energy. Like all DIY ingredients, there's room for fun experimentation—try adding a little orange or grapefruit juice, or using raw sugar or agave syrup. If you're just going to use your mix for margaritas, agave syrup with a combo of lime and orange juice could be just right.
There's a whole family of drinks called Sours that are liquor plus some form of sugar and citrus. You can make any of these drinks using your homemade sour mix—and they will be all the better for it. Mix equal parts whiskey and sour mix and serve it over ice for a whiskey sour. Or use the same formula to make a daiquiri, using rum instead of whiskey. Try it for margaritas or sidecars, adding Cointreau or triple sec and tweaking the formula to your taste. If you're feeling fancy, shake up a couple ounces each of pisco and sour mix along with an egg white and a few drops of bitters to make a pisco sour. For something a little lighter, try a Tom Collins by pouring shot each of gin and sour mix and topping off with club soda.