Dilution + Temperature Equilibrium
James Bond was/is incorrect. 007 may be a world renown spy, but I wouldn’t take his advice when it comes to cocktails.
Within the industry, it is commonly agreed upon that the ingredients in a cocktail shall dictate whether a drink should be shaken or stirred. Barring a few rare exceptions, if it contains fruit juices or an egg white, it must be shaken. If the drink only consist of sugar/syrups, spirits and bitters, it should be stirred.
Shaking or stirring is meant to blend ingredients together and also to dilute the cocktail with ice so that it chills and reaches its temperature equilibrium.
Each technique also has its own unique additive purpose. Shaking is meant to aerate the cocktail, while stirring is meant to maintain the delicate nature of the spirit in order to keep the viscosity silky.
Whichever method you are using, you must understand the intent is to bring the temperature of the cocktail down to either 32°F or 35°F through dilution.
Cocktail recipes are created with the forethought and expectation that it will be diluted with ice to balance and round out the flavors. If you don’t believe this, I would encourage you to do a little experiment.
Make 2 identical cocktails in 2 separate glass. Choose a stirred cocktail in order to keep the consistency between the 2 as close as possible
Cocktail 1(no ice): Place in the freezer until the temperature of the drink reaches 32°F on its own. Should be about 2 hours.
Cocktail 2: Once cocktail 1 is ready, add ice only to cocktail 2 and stir until the ice dilutes and the temperature is also 32°F
We now have 2 cocktails with the same temperature, but cocktail 2 will have been diluted with ice while cocktail 1 has not. Do a taste test at this time and let me know which one you prefer. My hunch is that you will enjoy the one that has been diluted more. Until there is an invention that can cool a room temperature cocktail down to the same temperature as ice in less than 60 secs, cocktail recipes will always be made with ice in consideration.
If you’re still with me, this brings us to the concept of temperature equilibrium and how to achieve it. If you haven’t been paying attention, I will summarize everything in 1 sentence. As Dave Arnold, the author of Liquid Intelligence states,
“there is no chilling without dilution. There is no dilution without chilling.”
It is the ice melting that is causing the cocktail ingredients to chill. If the ice did not melt, the liquid would not change. When we stir or shake, we are creating friction so that the ice will absorb the heat from its surrounding in order to melt, blend in and bring down the temperature of the surrounding liquid. Once the temperature of the surrounding liquid is the same as the ice, the ice will no longer melt.
Does shaking or stirring bring down the temperature quicker?
Quick Answer: Shaking
How long does it take for the surrounding liquid to be the same temperature as the ice?
Answer: This depends on which method you are employing and how fast you are dispersing the heat. Consider this chart from cookingissues.com
Blue: Shaken drink
Red: quickly stirred drink
Green: slowly stirred drink
All drinks started with the same volume of liquor and at the same temperature with equal weights of un-cracked Kold-Draft cube ice.
As you could see, the shaken drink reaches 0°C (32°F) or below consistently around the 9 to 10 sec mark.
The quickly stirred drink around 42, 43 secs
The slowly stirred drink around the 1min 20 sec mark
Although we roughly understand the time it takes to get to temperature equilibrium, we must also consider the diminishing return of the cost of time invested in shaking/stirring to the value we receive in the form of temperature decrease. Diminishing returns occurs around 30 seconds of stirring. This means that for the first 30 seconds of stirring, you will get a 21°-23° drop, but if you continue on for another 30 seconds, you’ll only see another 5° drop.
At the 30 second mark, you haven’t reached temperature equilibrium quite yet, but you would be close. If your bar is extremely busy, adding an extra 30 seconds for 5° may be a tradeoff to consider and determine if it’s worth the time or not. I’m not saying this is right or wrong. I’m always advocating quality over quantity. If it was up to me, I would say learn to stir quicker so that you could reach the desired temperature within 30-40 secs.
Regarding Shaking
We know that shaking is the quickest way to bring the temperature down. However, the type and shape of ice used in the shaking process will have an effect on the speed as well as the texture of the drink. As I mentioned earlier, shaking aerates the cocktail giving it a more frothy texture. This is why the shape and type is important.
Using small ice: The drink will get chilled quicker, which means quicker dilution due to more surface area of ice exposed to liquid. The trade off is, there would be less air being pushed around inside the tin during a shake because the ice would conform to the walls of tin with less open space for air to squeeze through. The result will be a cocktail with lots of ice chips, but less frothy in texture.
Using 1 large square 2” square cube: The shake will take a little longer to get to the desired temperature than the small ice, but the advantage is as the cube is tossed back and forth within the tin, there is plenty of space for liquid and air to pass by, creating a really desirable texture in the cocktail. The cube shape also provides more air resistance over the more aerodynamic sphere ice so it will push more air around during the shake.
Now that you understand the science behind why we shake and stir, I hope it will inspire you to look at your favorite cocktails in a different light and see how they could be improved with a simple change of technique or type of ice used. Be on the look out for my post on stirring using Japanese techniques. Cheers!