Boston Sour – 1972 Trader Vic’s Bartenders Guide Recipe

Boston Sour vs Whiskey Sour

There is debate whether to call this recipe a Whiskey Sour or a Boston Sour. I personally am going to go with Boston Sour and here is why. 1). I can find no cocktail books that list adding egg whites to a whiskey sour till the 1950s (Read the section below for more detailed information about when egg whites actually start being used in sours). Whiskey sours were traditionally just lemon juice, sugar, and bourbon. Adding egg whites to cocktails was considered girly, and no machismo man would want to be seen ordering a girly whiskey sour. Even if it made them feel super cute. 2). Traditionally cocktails with egg white like this had fun unique names to indicate that they were not a standard sour. White lady, pink lady, clover club, rattlesnake, million dollar cocktail, etc. The list goes on and on, but the name was always something other than “base spirit” sour. 3). Egg whites were listed as optional/non-traditional in sours from the 1950s -1960s and I can’t find a recipe that specifically says you must egg whites till the 1970s. The 1972 edition of Trader Vic’s Bartender’s Guide is the oldest use of the name Boston Sour I could find in publication that does not list egg whites as optional. If it’s in a book older than that, then it’s one I don’t have. I will say though I combed through a little over 100 books published between 1880 to 1972 looking for the Boston Sour and that was the first one I found.

So the TLDR of this is, Whiskey sours are not traditionally made with egg whites and the Boston Sour is the first version of this recipe I found to say you must use egg whites and that they are not optional.

To Add Egg Whites Or Not To Add Egg Whites

This has been the absolute single hardest cocktail to document and I try to keep my sources to only published books. Sometimes I use newspapers but I don’t give them much weight. The conclusion I have come to is a traditional whiskey sour, all sours for that matter, do not have eggs whites. Yes there were cocktails like the clover club or pink lady that had egg whites, or you can go back even further to the Fizz style cocktails from the 1880s that had egg whites. But not until the early 1950s am I able to find anyone use egg whites in a cocktail labeled a Whiskey Sour. Sour cocktails prior to the 1950s that used egg whites in this way all seem to have fun names and were presented as cocktails for the ladies. In the 1930s or 40s if a man ordered a whiskey sour and he was handed one with egg whites in it, he would probably be offended or think the bartender mixed his drink up with some woman’s at the bar. I looked through maybe 100+ books ranging from the 1880s to the late 1960s and this was pretty consistently what I found.

The earliest use of egg whites in a standard sour I could find was from King Cocktail by Eddie Clark. Who in 1947 was the successor head bartender to Harry Craddock at the Savoy. The 1955 official British Bartenders union cocktail book, The UKBG, also mentions using egg whites in sours, but both books say they are optional and not traditional. Assumedly egg whites were added upon request and not the normal way a whiskey sour was made. Keep in mind Harry Craddock, 1920 – 40s, did not make his sours with egg whites. All those cocktails had different fun names. Eddie Clark even grouped those fun cocktails in the “For ladies only” section of his book. Is this an example in”toxic”ated masculinity?

The Most Important Ingredient

Cocktails with egg whites are actually difficult cocktails to get right and anyone who says otherwise is projecting a false image. Everyone who has made a fizzes or sour with egg whites has had one of these pop open on them while shaking, only to make a mess. The best advice I can pass on to making any cocktail with egg whites is it comes down to 2 things; Technique and chemistry. A common technique that works very well is the dry shake. A dry shake is shaking all your ingredients together without ice first to make forming the foam easier. The foam will still form with ice but you will end up working twice as hard for half the result if you shake with ice first. The first shake is only about 20-30 seconds of vigorous shaking but this is the part that forms most of your foam. A little tip here is to wrap a kitchen towel around the seal of your shaker because no matter how strong you are or how tight your grip it will pop open a little. as the egg whites unfold they can expand up to 8x their original size, thus increasing the pressure inside the shaker and forcing small amounts of the sugary egg mix to squirt out. Wrapping a small towel around the shaker will catch this and keep things clean.

Next and more important is chemistry. For a cocktail with egg whites to properly foam you have to get the science right. Denaturing/unfolding egg protein into a meringue is more science than brawn and a friend of mine who is a baker once gave me this advice for how she made meringue at the bakery.

  1. Keep it room temperature.
  2. Use an acid to help break the proteins hydrogen bonds and unfold it in addition to beating it.
  3. Use sugar to stabilize the foam from collapsing and to form smaller bubbles.

A mistake I made for a long time is using is using eggs fresh from the fridge. Even if I’m doing a dry shake I’m still starting off with cold ingredients. So take the eggs out and let them come to room temperature first. Cold egg protein is much more stable and difficult to break apart than if it is room temperature. The next tip is to use acid. Bakers will use cream of tartar as the acid helps accelerate the denaturing process along with beating it. In the cocktail we use lemon or lime juice. Without using an acid it is much much harder to form a foam. The last bit of advice is to use sugar to stabilize the foamed protein from collapsing. A sweet liqueur alone isn’t enough. I’ve tried making cocktail with egg whites with just liqueurs for sweeter alone and they have never formed a good foam. This needs actual simple syrup. If you don’t use sugar in your cocktail what will happen is the foam will form but it will collapse back into the liquid-y cocktail just as fast and you will be left with a thin layer of lame bubbles on top. It will still taste the same and be good but that beautiful foam will be gone, and for these drinks the large foam head is the garnish. The sugar also somehow makes the water “wetter” and helps keep the suspended air inside from combining into larger bubbles. This helps form a smoother micro bubble head.

cocktail with egg whites are some of the most elegant and sublime cocktails but they are not the easiest to make. Eventually you can get to a point where you can make them correctly and consistently but it can take a while and many failed attempts. Hopefully the tips I gave help shorten that journey. Also theres a lot of tips and tricks out there for making eggs foam and I tried to keep mine reasonable and realistic, but see what works for you. I’ve been doing this for a long time and still I have the occasional one that doesn’t foam up well, even though I make them all the exact same. Its just the nature of the egg sometimes and I just accept it and make it again.


Boston Sour – 1972 Trader Vic’s Bartenders Guide Recipe

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Course: DrinksCuisine: American






Total time



Learn how to make a classic Whiskey sour with egg whites.


  • 1 oz Egg Whites

  • 2/3 oz lemon Juice

  • 1/2 oz Simple Syrup

  • 2 oz Bourbon


  • Combine all ingredients in the shaker. Shake dry for 30 second – egg foams better when not cold.
  • Now add ice to the shaker. Vigorously shake again till the shaker is ice cold and frosted.
  • Strain into glass to remove ice shards

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