A fascinating study led by Professor Claudio Pellegrini, an expert in thermal and fluid physics at the Federal University of São João del-Rei, addresses an interesting question: What shape should a beer glass have to keep beer cold the longest? To answer this, Professor Pellegrini and his team identified the mathematical and physical formulas for various types of beer glasses popular worldwide, including tulip glasses, British pints, American pints, Weizen glasses, and the familiar mug often referred to as “the tankard”…
Popular types of beer glasses around the world.
The Brazilian physicists’ research maintained fundamental formulas and conditions that affect how the temperature of beer in a glass is influenced by the surrounding environment, such as the impact of foam and the heat transfer from the drinker’s hand through the glass. They evaluated these processes alongside various parameters of the beer glass, such as the height of the glass, the diameter of the base, the maximum bulge diameter of the glass, and the height of the poured beer inside the glass…
Ultimately, they concluded that to keep beer cold the longest, the glass should resemble the one shown below, considering both the Imperial pint (approximately 568 ml) and the American pint (approximately 473 ml):
In this study, Professor Pellegrini focused solely on transparent glass types, and most of them feature relatively thick bases or are taller than the table surface. He noted: “In tropical countries like Brazil, the everlasting issue is keeping beer cold during consumption, especially in coastal areas.”
“The process is fundamentally simple: You order beer, the waiter brings it, and then you drink. This process repeats over and over. However, the moment the beer is poured into the glass, it begins the heat transfer process with the surrounding environment, which continues until thermal equilibrium is reached with both the environment and the glass. This is something no one desires. Depending on the temperature difference between the outside and the beer, it can take just a few minutes before it’s undrinkable. For instance, at a coastal temperature of 38 degrees Celsius, our calculations indicate that it takes only 3 minutes for the heat transfer process to complete, rendering the beer warm.”
The research by Brazilian physicists revealed that there is indeed an optimal beer glass design for keeping this alcoholic beverage cold. The tall glass with a flared rim in the first image is essentially the same as a Pilsner glass. Naturally, Pilsner glasses come in various designs to enhance aesthetics, but the best shape for keeping beer cold is the flared rim, rather than a tapered one. Based on calculations, this is the shape that allows for the longest cold retention.
Based on calculations, this is the shape that allows for the longest cold retention.
Professor Pellegrini humorously shared that aside from “personal benefits,” he conducted this research to engage his students more with aspects of learning and research that can sometimes feel abstract, dry, and unappealing.
