Flavors of Brazil that Brazilians generally like their beer to be served cold - extremely cold. When asking for a beer, most will tell the waiter that they want the beer to be bem gelada (well chilled), geladinha (quite cold), or even estupidamente gelada (stupidly cold). The Brazilian gold standard in a beer is a medium-light lager served at the coldest possible temperature. But what IS the coldest possible temperature for beer, and how close to Brazilians come to achieving that standard?
AmBev which controls the largest market share in Brazil for beer. (The photo at right shows a refrigerator advertising Antartica beer, one of AmBev's products.I'm not certain, but I'm guessing that the bars receive these fridges free from the breweries in exchange for selling that brewery's brand in the bar. These fridges normally have a digital thermometer prominently displayed near the top of the door. This allows the bartender or waiter (and discerning customers) to monitor the temperature inside the fridge.
Beer freezes at a lower temperature than water, due to the presence of alcohol in the brew. Pure alcohol has an extremely low freezing temperature: -114C or -173F. But beer of course is only 4 or 5% alcohol, and the rest is water, which freezes at 0C or 32F. The fact that beer is carbonated and bottled under pressure also lowers the freezing temperature.
So last night, while chatting and snacking with my party, I began to watch the temperature changes for one particular fridge. When the door hadn't been opened in a while, the temperature hovered around -7.5C or -8C. That's cold! In Fahrenheit it would be between 17 and 18F. Every time the door was opened for someone to grab a bottle of beer, the internal temperature would rise to -5C or so, then settle back down to -8C. My curiosity was spiked, so this morning I did some elementary research on the internet. It appears that the freezing temperature of most beers is around -8.5C or 16.5F. The beer in that fridge last night, when first removed from the fridge, were very close, therefore, to the coldest possible beer. No wonder it tasted so good - particularly as we were outside in the tropical night, and the air temperature at midnight was about 28C or 82F. That means there were 36C or nearly 100F degrees of difference between a freshly poured beer in that bar and the ambient temperature!
There is one undesired side-effect of this Brazilian passion for ice-cold beer and bars attempts to please their customers. From time to time the fridges get too cold and the beer reaches a temperature at which it is still liquid in the unopened bottle, which is pressurized, but at which the beer freezes instantly when the bottle is opened and the pressure is released. It's happened to me several times - a bottle of beer arrives at the table looking nice and frosty. The waiter opens the bottle and then tips it to pour out the first round into our glasses, but nothing comes out. The beer is a solid chunk of beer-popsicle inside the bottle. At that point nothing can be done, as thawed beer loses all of its charm and carbonization. Waiters are generally good-natured about it when it happens though, and soon return with a beer that's only slightly less estupidamente gelada.