Sweet & Sour Mix, also called “Sour Mix” or “Lemon Sour Mix,” is a citrus-flavored sweetener that has been used in cocktails since the 1800s. Large bottles of its premixed ingredients can be found in stores, but I don’t recommend using those because just about all of them are made with reconstituted citrus juices or citrus peel oils, which have a very different flavor than fresh citrus juice. Instead, I make ours at home to achieve the freshest flavors possible that are closer to what the cocktail’s creator intended. The process is very simple, much like that of homemade simple syrup or grenadine.
Add 100 g sugar and 100 ml hot water to a saucepan.
Heat over medium high heat while stirring for 3-5 minutes until sugar is dissolved but water is not yet boiling, then remove pan from heat.
Add lemon juice and lime juice to pan, stir for 5-7 seconds, cover, and let cool for 10 minutes.
Strain mix through a fine mesh strainer 1-2 times to remove any sugar particles.
Pour mix into a squeeze bottle or pouch with a spout using a funnel, then refrigerate or freeze.