Liquid Cool: The Science Behind Below Zero BeerDecember 18, 2018
- Nico GocoWords
When I first heard about Below Zero Beer, I thought it was just a fad that wouldn’t last. After all, while I like my beer very cold, I was concerned that a nearly frozen beer would lose all flavor.
Man, was I wrong.
When you take that first swallow of your subzero brew on a hot summer day, it’s an eye-opening experience. Even years later, I find that I still occasionally enjoy drinking beer this way.
But how do they do it? Are we at the height of scientific advancement that beer molecules can be controlled at some magic brew master’s will? Are alchemists and sorcerers involved? After all, we’ve been taught that water freezes at zero degrees Celsius. So how come this beer gushes out cold yet smooth instead of freezing solid?
Sadly, no witchcraft is actually involved. The answer lies in a few well known scientific phenomena: Freezing Point Depression and Supercooling. In fact, people have been taking advantage of these principles for centuries. They’re the ones responsible for beer’s ability to stay liquid at freezing temperatures.
Here are the reasons why beer can stave off the hand of Jack Frost:
- Beer is a solution, which means it’s water with other stuff (like alcohol, adjuncts, and carbon dioxide) dissolved in it. That other stuff lowers the freezing point of water to between -2° to -6° Celsius.
- The glass bottle helps to keep it liquid at even lower temperatures. To become ice, beer molecules need to attach themselves to rough surfaces or solid impurities. But since the bottle’s insides are so smooth, ice has a hard time finding purchase. This is called supercooling, and it keeps your beer nice and drinkable even way below the freezing point.
- The freezer they use isn’t anything out of the ordinary. The temperature is just slightly tweaked to keep beer at a temperature where it won’t freeze so easily. To further avoid beer from freezing (and the broken bottles that would result from the liquid’s expansion), the barkeep follows a timed cycle to shuffle the bottles around. This helps maintain a controlled temperature inside the freezer and in the beer bottle itself.
Right after they pop open the bottle, the beer is at a very sensitive phase. Any change in its balance can cause ice to form immediately. This is why tapping the bottle, or pouring it into a glass will make it freeze.
Why do some people like beer below zero? At such a low temperature, a lot of the bitter flavors are subdued. The cold helps hide the bitter and strong flavors of the beer. The sweet and rounder flavors are heightened, and the beer is easier to drink.
Not all beers will benefit from the below zero process, though. Some beers are best served cool or slightly cold, and drunk slowly to savor the flavors. The Beer Guide for Dummies states that you’re better off drinking a Slurpee instead, since very cold temperatures will ruin your beer. Beer aficionados also fault large breweries for promoting ice cold serving temperatures, as this can help mask their beer’s flavor flaws.
Still, with our hot and humid climate, a beer served below zero can do wonders to fill the void she left in your heart to refresh you. You can even try making some at home if you want. A mythbusters episode reports that the beer should stay for about three hours inside your freezer to be supercooled.
Do you like your beer served below zero? Did you ever drink from the bottle too fast and got your tongue frozen stuck? Share your woes in the comments!