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This rum sour recipe is delightfully sweet tart! Pair any type of rum with lemon juice and simple syrup for a fun and easy cocktail.

Rum Sour drink in cocktail glass with cherry and lemon garnish
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Got rum and not sure what to do with it? Make a rum sour! This classic sour cocktail is delightfully sweet tart, pairing any type of rum with lemon juice and simple syrup. Top it off with an egg white foam topping, which gives it a creamy mouthfeel. It’s irresistibly refreshing: and simple to make! As two cocktail experts, the sour is always a favorite: we’ve tried it every which way from whiskey to pisco. Each type of liquor brings a new twist, and this rum sour is a stand-out!

Ingredients in rum sour

The rum sour is a spin on the whiskey sour, a classic cocktail from the 1880’s. Traditionally sour cocktails have three parts: liquor, citrus, and sweetener. In the 1920’s, sours were often served with an egg white foam on top to add a frothy texture and creamy body to the drink.

To make a rum sour, use rum as the liquor. We like it with dark or aged rum to add a nuanced, sophisticated flavor, but white rum works too. Here’s what you’ll need for a rum sour recipe:

  • 2 oz dark or aged rum (or white rum)
  • 1 oz lemon juice
  • ¾ oz simple syrup
  • Egg white
Rum Sour cocktail with rum bottle

Types of rum

This rum sour works with any type of rum, but dark and aged rum are our favorite here. Taste the different varieties of rum, and you’ll find that they almost taste like different liquor. Here’s an outline on types of rum:

  • Dark rum has a deep, caramel flavor and notes of cinnamon and spices (see Dark Rum Drinks).
  • Aged rum, aka golden or añejo rum, has notes of vanilla, coconut, almond, citrus, or caramel.
  • White rum has a straightforward flavor with the signature fruity finish.

As a note, coconut rum is a sweet coconut-flavored liqueur made with rum (Malibu is the most popular). We wouldn’t recommend using it for a true rum sour, but you certainly can try it for a tropical-tasting spin on the drink.

Rum sour cocktail with dark rum bottle.

Use a “dry shake” for the egg white foam

Bartenders have added egg whites to cocktails since the 1860’s to add a frothy texture to the surface, as well as a creamy rich flavor. Is it safe to add raw egg whites to drinks? Turns out, the risk of salmonella is very low. In fact: melons, salad, and peanuts, have more of a threat for salmonella than eggs! Here’s how to safely store and use eggs to minimize risk. If you prefer, you can substitute aquafaba as a plant-based equivalent to the actual egg white (see below).

The best frothy egg white foam is achieved by doing a dry shake. This move is used in classic cocktail recipes like the Gin Fizz. Here’s how it works:

  • The first shake without ice lets the protein in the egg begin to form foam, instead of being diluted by the ice.
  • The second shake with ice cools the drink and strengthens the foam. Strain it into the glass and you’ll get a thick, white frothy layer.

How to make a rum sour (basic steps)

The rum sour is quick and easy to make. The only time involved is juicing the lemon and separating out the egg white! Otherwise, it’s a simple mix, shake, and strain using a cocktail shaker. Here are the basic steps (or jump right to the recipe):

  1. Place all ingredients in a cocktail shaker. Shake vigorously for 15 seconds without ice.
  2. Add ice to the cocktail shaker and shake again vigorously for 30 seconds.
  3. Strain into a glass and garnish with a cocktail cherry and lemon slice.
How to make a rum sour cocktail recipe with lemon half

A substitute for egg whites in cocktails

Want an egg white foam in your cocktail without raw egg? Don’t worry: you can use aquafaba! Aquafaba is the liquid that’s in a can of chickpeas. Because it’s starchy, it can work as a binder similar to an egg. Use the following formula: Two tablespoons of aquafaba equals one egg white.

And that’s it! Let us know what you think of this rum sour recipe in the comments below. We hope you’ll love it as much as we did!

More rum drinks

Got rum? Here are a few more top rum cocktails to try:

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Rum Sour

Rum Sour


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5 from 1 review

  • Author: Sonja Overhiser
  • Prep Time: 5 minutes
  • Cook Time: 0 minutes
  • Total Time: 5 minutes
  • Yield: 1 drink 1x
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Description

This rum sour recipe is delightfully sweet tart! Pair any type of rum with lemon juice and simple syrup for a fun and easy cocktail.


Ingredients

Scale
  • 2 ounces* aged or dark rum (or white rum)
  • 1 ounce lemon juice
  • ¾ ounce simple syrup
  • 1 egg white*
  • For the garnish: cocktail cherry, lemon slice

Instructions

  1. Add the rum, lemon juice, simple syrup, and egg white to a cocktail shaker without ice. Shake for 15 seconds.
  2. Add the ice to the cocktail shaker. Shake again for about 30 seconds until cold.
  3. Strain the drink into a glass; the foam will collect at the top. Serve with a cocktail cherry.

Notes

*To convert to tablespoons, 1 ounce = 2 tablespoons. 

  • Category: Drink
  • Method: Cocktail
  • Cuisine: Cocktail
  • Diet: Vegetarian

About the authors

Sonja & Alex

Hi, we’re Alex and Sonja Overhiser, married cookbook authors, food bloggers, and recipe developers. We founded A Couple Cooks to share fresh, seasonal recipes and the joy of cooking! Our recipes are made by two real people and work every time.

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1 Comment

  1. Sonja Overhiser says:

    Let us know if you have any questions!