Nearly early modern mixed drink involves ice. You can make amazing drinks with rudimentary spirits and MacGyver equipment, but without ice, the drink falls flat. Besides the obvious cooling effect, ice also dilutes the drink, reducing the overall percentage of alcohol and increasing the volume. While dilution might seem non-desirable, trust me – you want it, at least up to a certain point. Our palates are tuned to a particular flavor intensity, and without adding water the flavors would be too intense.
When it comes to using ice in drinks, here’s a fun science fact most folks don’t know: There’s a direct relationship between the amount of cooling and the resulting amount of dilution. Here’s why: Heat energy naturally flows from warmer to cooler, e.g from your warm(er) liquid ingredients to your colder ice. Let the mixture sit long enough and a near equilibrium is established – The liquid and the ice both at nearly 0 degrees Celsius (32F), and the ice melting only very slowly. Most of us have observed this firsthand on many occasions with an ice filled glass of soda.
A tiny bit of science now. It takes .5 calories of energy to increase the temperature of 1 gram of ice by one degree Celsius (C). However, it takes 80 calories of energy (160 times the amount) to convert ice at 0 C (32 F) into water at the same temperature. When you add ice to drink, it rapidly warms to 0 C, but then what? As long as the liquid is warmer than 0 C, there’s still “excess” heat energy in the liquid ingredients, and that energy has one thing on it’s minding: Melting that ice!
The long and short of it is that the vast majority of the cooling effect of ice is from ice turning into water. It’s the law – the law of thermodynamics. That’s enough science for now, but if you’re intrigued, I highly recommend an amazing article that extensively covers of topic of ice and cocktails. It has a fair amount of science yet is highly readable. It had a huge effect on how I think about drink preparation.
You might be wondering “Is there some way to chill a drink with less dilution”? For instance, what about those “whiskey stones”? While they do chill a drink, the amount of cooling they provide is fairly minimal. Their cooling effect stops the moment they reach the same temperature as the liquid, which is fairly quickly. No, melting ice into water is a much more efficient cooling method. The other obvious trick to prevent dilution is to chill the liquid ingredients themselves. I generally chill my citrus juices, vermouths and syrups, but don’t chill my liquors. Although if you’ve got a bottle of vodka in your freezer, go ahead, knock yourself out!
Mixed drinks incorporate ice by one of three methods: Stirring, shaking, or blending. Stirring introduces the least amount of dilution and cooling, while blending causes the most. You might be wondering “How does a bartender know which technique to use?” There’s a general rule of thumb: Drinks with all clear ingredients are stirred. Everything else is shaken or blended as appropriate. Shaking a drink cools a drink faster than stirring, although it’s possible to cool it just as much via stirring. It will just take you a long time – two minutes if you read the article I mentioned earlier.
With this rule in mind, let’s go through a few classic drinks and figure out whether they should be stirred or shaken:
- Margarita – The lime is cloudy. Shaken
- Manhattan – Bourbon/Rye and vermouth, both clear. Stirred.
- Martini – Gin or Vodka, vermouth. Stirred. Sorry James…
- Mai Tai – Lime or other citrus fruits, and likely the syrups will be cloudy. Shaken.
- Negroni – Gin, Campari and Vermouth – All clear. Stirred.
- Pina Colada – Blended, obviously!
Can you bend the rules? My personal take is that if you feel like stirring something that would normally be shaken, go for it. It’ll either not get as cold or will take longer. However, it does provide more control over the amount of dilution. As for shaking a stirred drink, don’t do it! I once ordered a Manhattan and couldn’t see the bartender making it. I could tell immediately it had been shaken, and was completely terrible. As for blending, I like my Pina Coladas shaken. Some would call that sacrilege, but I can make a compelling argument for it.
Finally, a public service announcement about straining. When shaking a drink, the ice cubes violently smash against each other and the sides of the shaker. Naturally this causes the ice to fragment into smaller pieces. Some ice pieces are just small enough to slip by whatever basic strainer the bartender uses, e.g. a Hawthorne strainer. Once in your glass they melt and dilute the drink further. Worse, they form mini-icebergs that interfere with the drink texture. It’s one of my cocktail pet peeves. When serving a drink “up” (without ice, in a stemmed glass) good bartenders use a second, much finer strainer held over the glass to capture anything undesirable, including ice chips. I do this myself and am always surprised by how much ice I catch. Watch for it the next time you pull up a seat at your favorite bar.