Boston Sour Cocktail: A Smoother Version of a Whiskey Sour

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This Boston Sour recipe is so easy to make with only a few ingredients. It’s a great time to learn how to make cocktails with egg whites.

One of the things I learned traveling is that I love sour cocktails. I made so many pisco sours in Peru working at a hostel bar in Cusco and yet I never grew tired of drinking them.

That time in Peru was eons ago but I still love exploring new kinds of sours. The inspiration for this Boston sour recipe is my Aunt Margaret.

She’s been looking to visit Boston for a while but hasn’t made it. 

And so I’m bringing Boston to her.

Boston sour cocktail - bourbon with lemon juice, sugar syrup and egg white in glass. Vertical orientation.

What is a Boston Sour?

It is essentially a whiskey sour with egg white. It’s basically to a pisco sour but instead of using pisco you use whiskey or bourbon whiskey.

Now, this can be confusing because in some bars a whiskey sour DOES have egg white.

But back in the day in a lot of American cities it was a terrible drink that used cheap whiskey, some kind of sour syrup mix or powder.

And so calling it a Boston sour ensures you’re getting egg white instead of cheap cocktail mix.

Don’t be afraid to use egg white. As long as you’re using fresh eggs and you aren’t letting the cocktail sit outside all day in the sun you’ll be fine. 

It doesn’t taste eggy at all. The egg whites add a really nice creamy, smooth frothiness to the drink.

And if you’re not a fan of whiskey try this Empress gin sour recipe, which is such a pretty lavender colour.

The first Boston sour I’d ever made, when I lived in Toronto.

How to Make a Sour

A sour is a type of cocktail that can be made with any kind of spirit. You simply need the three S – spirit + sour + sweet: 

  • Spirit (pisco, whiskey, rum etc)
  • Sour – usually some kind of citrus
  • Sweetner – usually simple syrup.

And so it’s not a requirement to have egg white in a sour cocktail. However, most bartenders now do prefer to add egg white as it smooths out the drink.

Boston sour cocktail - bourbon with lemon juice, sugar syrup and egg white in glass. Vertical orientation.

Whiskey Sours Were Once Considered Healthy

Like many inventions, there are varying opinions as to who invented the whiskey sour.

Some say Elliot Stubb, who is often credited with inventing the pisco sour, also invented the whiskey sour in Northern Chile in 1870.

Others believe it was closer to home.

If you’re North American and remember any of your history classes you’ll recall that scurvy. Sailors often suffered from lack of vitamin C and would die from it. 

To combat this illness a British naval officer, Vice Admiral Edward Vernon, concocted a type of medicine. It added lemon, lime or other citrus to whatever spirits they had on hand.

And since it was alcoholic, sailors had no issue taking their medicine.

It wasn’t until hundreds of years later that the first Boston Sour was documented. In 1892 egg white was introduced as an ingredient to smooth the harshness of cheap whiskey.

Whiskey sours were a popular drink during prohibition time. And today if you need a reason, August 25th is whisky sour day.


A Modern Boston Sour Recipe

This sour drink recipe is so easy, you’ll wonder why you ever paid $17 for one at some chi chi cocktail bar. It only requires a few ingredients and they are easy to find. 

Some serve it in a coupe glass, but really it’s fine in any short glass.

If you have a cocktail shaker you’ll want to dry shake the cocktail first to build volume then shake again with ice cubes and finally strain into a coupe or rocks glass.

A dry shake without ice gives a bit more velvety creaminess to the drink.

But First…How to Make a Simple Syrup

So many classic cocktails call simple syrup. DO NOT buy it.

Making a syrup just for cocktails sounds complicated but it’s really simple…hence the term simple syrup.

Over medium-low heat put equal parts of water and white sugar into a saucepan and stir.

Once the sugar has dissolved into the water remove from the heat and let cool. Voila!

This recipe calls for equal parts simple syrup and lemon juice, but I like my cocktails on the less sweet side so I’ll often only use 1/2 oz of simple syrup to 3/4 oz lemon juice.

Boston sour cocktail - bourbon with lemon juice, sugar syrup and egg white in glass. Square orientation.

Boston Sour Cocktail

Yield: 1
Prep Time: 2 minutes
Additional Time: 3 minutes
Total Time: 5 minutes

This Boston Sour recipe is so easy to make with only a few ingredients. It's a great time to learn how to make cocktails with egg whites.


  • 2 oz whiskey
  • 3/4 oz simple syrup
  • 3/4 oz fresh lemon juice
  • 1 small egg white (should be 1/2 ounce)
  • A few dashes of Angostura bitters


  1. Dry shake whiskey, simple syrup, fresh lemon juice and egg white in a cocktail shaker for 10 seconds. Then add four ice cubes and shake for five seconds.
  2. Strain into a chilled coupe or rocks glass. 
  3. Add a few dashes of Angostura bitters.
  4. Optional: garnish with a cocktail cherry.


Disclaimer: Although I have never had an issue with raw egg whites it isn't for everyone. The elderly, children under 5 and people with weak immune systems should avoid the raw egg whites to avoid the risk of salmonella.

Nutrition Information:
Yield: 1 Serving Size: 1 Amount Per Serving: Calories: 186Total Fat: 0gSaturated Fat: 0gTrans Fat: 0gUnsaturated Fat: 0gCholesterol: 0mgSodium: 43mgCarbohydrates: 12gFiber: 0gSugar: 11gProtein: 3g

Nutritional information is provided as a courtesy and is an estimate only. This information comes from online calculators. Although attempts to provide accurate nutritional information, these figures are only estimates.

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Variations of the Boston Sour

New York Sour / Continental Sour / Greenwich Sour:  the Boston sour recipe with a couple spoonfuls of red wine, such as a Bordeaux, on top to make a red wine float

Ward 8: the Boston sour recipe with lemon and orange juice as the sour, and grenadine as the part of the sweetener.


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Join the Conversation

  1. Margaret VanBlarcom says:

    Wow, cant wait to try this . You have one lucky Aunt Margaret! You make recipes so easy … love it!

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