Cocktail Science

Studying the science behind your drinks.

The Fastest Way to Chill a Cocktail Glass

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[Photos: Kevin Liu]

The other day, I was walking around Annandale, VA when I decided to wander into an appliance store that specialized in products imported from Korea. We're talking stoves, microwaves, freezers—the works. But one appliance completely surprised me. It looked like a normal refrigerator from the outside, but where neatly arranged shelves should have been on the inside, instead sat row upon row of pink plastic containers.

It looked like a fridge designed for nothing but leftovers. When I questioned the store's owner as to why someone would design and market a refrigerator designed solely for leftovers, he explained that they were actually meant for another, even more niche use: kimchi. That's right—there are actually 20-cubic-foot behemoth home appliances designed to house a single food item.

But, as I giggled over the absurdity of maintaining a refrigerator only to house pickled cabbage, I secretly harbored the guilt of knowing I too was running a refrigerator dedicated solely to a single passion: cocktails.* That's right: over the years, my stock of cocktail syrups, perishable fortified wines, and garnishes has grown so huge that I fear someday it will tip over and drown me in a flood of nicely-chilled vermouth.

And what about the freezer section of the refrigerator? That's where I store my Tovolo ice trays for perfect 2-inch cubes of ice, as well as a selection of cocktail glasses that always stay perfectly chilled.

But I know that not everyone can afford to maintain a freezer stocked with glassware, so I recently did a few experiments to find out the best (and fastest) way to chill a cocktail glass.

*Well, I keep beer in it too, but just stick with the story, k?

Why Chill a Cocktail Glass?

First, let's start with the basics. When you shake or stir a cocktail with ice, the end temperature will be somewhere slightly below 32°F/0°C. The exact temperature will vary depending on your other ingredients, room temperature, etc. but suffice it to say the cocktail will end up somewhere just below the freezing point of water.

In theory, your cocktail is at its perfect temperature and dilution immediately after it was made, so the point of chilling a cocktail glass is to keep the cocktail it houses at the ideal temperature for as long as possible.

Does it Work?

Luckily, I don't need to run experiments to prove that chilling glassware matters. That's because the awesome Frederic Yarm has already done meticulous tests to prove that chilled glassware keeps a cocktail chilled much better than a room-temperature glass can. The effect is even more pronounced when you use thicker glassware.

Yarm ran tests with both freezer-chilled glassware and glasses that had been filled with ice and water to get down to temperature. Depending on your appliance, glasses chilled in a freezer can drop down to almost 0°F while a glass chilled with ice and water will never drop below 32°F (since that's the freezing point of water).

The Absolute Fastest Way to Chill a Glass

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[Photo: UC Davis College of Engineering]

Before I get into the tests I ran, let's get one thing out of the way: If you're looking for the no-kidding fastest way to get a cocktail glass from room temperature down to really cold, look no further than the liquid nitrogen method pioneered by David Arnold.

Nitrogen stays liquid at temperatures under -320°F/-195°C. That's really cold. In fact, the only reason the extreme cold of the material doesn't shatter the glass from thermal shock is because a gaseous layer of nitrogen forms around the liquid and serves as insulation.

I've seen Dave Arnold's bartenders use liquid nitrogen to chill glasses at Booker and Dax in New York, and the technique is both quick and effective. But, since most of you (and I!) might not be willing to invest in a dewar full of nitrogen, I'll leave that technique to the pros.

The Test

When Frederic Yarm did his exploration of cocktail glass chilling, he did a quick comparison between chilling a glass by filling it with ice water vs. putting the glass in the freezer.

The results? Water and ice gets a glass down to its coldest temperature—just above the freezing point of water—in about 6 minutes. It took Frederic's freezer about an extra minute to get a glass to the same temperature (it continued to get colder after that).

Could I do better? I needed to find a technique that could get a glass down 32°F/0°C (and perhaps below) in less than six minutes for it to be more effective than currently established methods.

What didn't work:

I tried a bunch of different techniques based off guides and myths popularized online. Here's a quick summary and a few notes about why these methods didn't work.

  • Evaporative cooling using water—I tried misting a glass with a spray bottle of water and then blowing on the glass with a fan. Slow and not even a little effective.
  • Evaporative cooling using alcohol—I tried misting a glass with vodka and blowing it with a fan. Still not cold enough and pretty slow.
  • Salt and Water mix—combined water, salt, and ice, then dunked a glass in it. This worked very quickly, but the residual salt in the glass was noticeable no matter how much I rinsed it.

What did work:

Three of the techniques I tried beat the 6-minute threshold.

First, a disclaimer: I did these tests for fun and not so I could publish my results in a scientific journal. I don't own a thermistor, so I had to use an infrared thermometer.* That means that whenever I measured the temperature, it interrupted the test, so I had to set up a new test for every data point I gathered. I hope you can understand why, then, I only took measurements every 30 seconds.

I also didn't perfectly control room temperature or the temperature of my freezer, etc. etc. but everything was pretty close, and I think the basic takeaways are sound. But for those of you who care about experimental design, I did want to be upfront with my less-than-completely-scientific methods.

*Infrared thermometers are designed to measure the temperature of black bodies and can give false readings when used on reflective surfaces (like shiny metal) or transmissive surfaces (like a cocktail glass). I did do some tests to make sure the thermometer registered the glass and not things behind it, but an infrared thermometer is still not ideal for this sort of test.

3rd Place: The Wet Towel Trick (3 minutes)

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A number of people on the internet recommend wrapping a wet paper towel around a wine bottle and tossing it in the freezer to speed up chilling. The technique works well for cocktail glasses too.

Simply wet a paper towel and squeeze out excess moisture. Wrap it tightly around the bowl portion of the glass and put it in the freezer. I found that three minutes got the glass down to about 35°F/2°C.

Why does it work? When water changes from a liquid to a gas, it draws in a massive amount of heat from its surroundings. The inside of a freezer is very dry and that environment causes the water on the towel to vaporize quickly. If you were to just spray a glass with water, the water would pool in the bottom of the glass and evaporative cooling would only chill that spot. The paper towel helps to spread the effect over the whole glass.

2nd Place: Fan in the Freezer (2 minutes)

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My freezer has a vent where cold air comes out. To trigger the fan that blows the air from that vent, I simply opened the door of the freezer until the temperature inside warmed up enough to trigger the compressor. Then, I put my glass directly in front of the vent. If you don't have a freezer with a fan, you could always buy a small battery-powered fan.

Why does this work? In a word, convection. With convection, cold air near the glass constantly gets replaced with new cold air, which causes the glass to chill rapidly. By adding a fan, convection is made much more efficient. Using a battery-powered fan will be less effective than using the super-chilled air straight from the freezer's vent, but you'll still get most of the benefits of convection. This is the same principle that helps convection ovens cook faster than conventional ovens.

1st Place: Really Cold Vodka (30 seconds)

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Think of this as the poor-man's version of liquid nitrogen. I left a bottle of vodka in my freezer overnight. When I checked it the next day, it registered a frigid 12°F/-11°C.

To chill my glass, I simply poured the cold vodka into the glass and let it sit. After thirty seconds, the glass registered 30°F/-1°C. After a minute, it had dropped to 26°F/-3°C. Not bad. When the vodka had done its work, I poured it into a tupperware container to use again.

Why does this work? Alcohol has a much lower freezing point than water does and it has a much greater specific heat and density than air does. Which means that alcohol chills much faster than air at the same temperature.

Another benefit to this technique is that only the bowl of the glass gets chilled; the stem stays comfortable to the touch.

Of course, the major downside is that you impart a slight taste of vodka to your drink. I tried wiping out the residual alcohol with a towel, which helps. I also tried wrapping the glass in plastic wrap first, but that actually insulated it and kept the technique from working.

So, What Would I Do at Home?

If anything, my tests have simply given me one more cocktail-related thing to store in the freezer. Imagine rinsing glasses for Sazeracs with freezer-chilled absinthe. Cold and delicious!

With that being said, if I ever did find myself without chilled cocktail glasses and in a hurry, I'd probably toss a few glasses in the freezer with a mini fan, since that would be simple, effective, and not a lot of work.

Do you chill your cocktail glasses? What's your technique?

About the author:Kevin Liu likes to drink science and study cocktails. Wait, that's backward. Ask him geeky food and booze questions on twitter @kevinkliu. While you're at it, check out his book about cocktail science.

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