Combine sugar and water over medium heat. Stir until combined and remove from heat. Let cool for 10 minutes.
1 cup water, 1 cup granulated sugar
Stir in lemon juice and lime juice until well combined.
1 cup lime juice, 1 cup lemon juice
If using right away, stir in 1-2 ice cubes to reduce the temperature. Otherwise decant into a jar or bottle and store in the fridge for up to 2 weeks.
If a frothier sour mix is desired (such as for whiskey sours), you can mix in 2 egg whites to the cooled mixture. Shake well to combine. If adding egg whites, use within 2 days.
2 whole egg whites
Notes
Citrus tips: Use fresh lemon and lime juice for the freshest taste, but the bottled concentrate will work perfectly fine. For fresh lemon juice, you will need about 6 lemons. For fresh lime juice, you will need about 8 limes.Mix it up: Play with the ratio, or mix and match with other citrus juices like orange or grapefruit. Adjust the batch size: This recipe is easily to scale up or down. Use ½ cup measures for a smaller batch, or double it if you are planning a party. Use the +/- buttons at the top of this recipe card to scale the recipe as you need to.