New Technology Creates a More Eco-Friendly Head on Your Guinness

Just in time for St. Patrick's Day, Irish mathematicians discover a biodegradable alternative to the plastic widget in cans of Guinness.

As St. Patrick's Day draws near, many of you may be anticipating a nice chilled glass of Guinness, complete with a creamy foam head. But if you're not propping up a bar in Ireland, and are instead pouring your beer out of a can at home, that long-lasting head can only be produced with the help of a plastic widget.

Simply pouring a carbonated beer, such as a lager, from the can into a glass is enough to generate a head. But this is not the case for stouts, which are infused with nitrogen bubbles, rather than carbon dioxide, in order to create their uniquely smooth texture. The small plastic widgets in each can of stout contain pressurized nitrogen, which is released once the can is opened, triggering some of the dissolved nitrogen in the beer to bubble up into a head.

Using applied mathematics, including the ideal gas equation and a fourth-order Runge-Kutta scheme with a timestep of 10-3, however, a team from the University of Limerick in Ireland recently discovered that microscopic plant fibers made of cellulose, such as cotton, can also froth up a stout.

In a paper publishing their findings earlier this month, the Limerick mathematicians conclude:

A typical pouring time for a stout beer is 30 seconds. In this time about 108 postcritical nuclei must be released. A single fibre produces one bubble every 1.28 seconds. Therefore about 4.3 × 106 fibres are needed. If each fibre occupies a surface of area λ2 then the total area that must be occupied by fibres is 8.3 × 10-4 m2.

Or, in plain English, embedding a 1 inch square of food-safe biodegradable cellulose fibers in a Guinness can would produce a perfect creamy head, doing away with the need for plastic widgets altogether. And although the technology is a long away from the shelves yet, removing plastic from our food chain is certainly something to drink to.

Images: Thumbnail (cc) by Flickr user raygunb (1) Courtesy of Michael Devereux/Mathematics Applications Consortium for Science and Industry, via Wired, still showing how pockets of air trapped in tiny cellulose fibers, each between 10 and 50 microns wide, help nitrogen and carbon dioxide bubble out; (2) the Guinness widget (cc) by Flickr user slworking2, via Wired.

via The Hill / Twitter

President Trump's appearance at the World Economic Forum in Davos, Switzerland was a mixed bag.

The theme of the event was climate change, but Trump chose to use his 30 minutes of speaking time to brag about the "spectacular" U.S. economy and encouraged world leaders to invest in America.

He didn't mention climate change once.

Keep Reading
The Planet
via David Leavitt / Twitter and RealTargetTori / Twitter

Last Friday, GOOD reported on an infuriating incident that went down at a Massachusetts Target.

A Target manager who's come to be known as "Target Tori," was harassed by Twitter troll David Leavitt for not selling him an $89 Oral-B Pro 5000 toothbrush for a penny.

He describes himself as a "multimedia journalist who has worked for CBS, AXS, Yahoo, and others."

Keep Reading

The Australian bushfires have claimed 27 human lives, an estimated 1 billion animals are feared dead, and thousands of properties have been completely decimated.

The fires were caused by extreme heat and dryness, the result of 2019 being the country's hottest year on record, with average temperatures 1.52C above the 1961-1990 average.

The area hit hardest by the fires, New South Wales, also had its hottest year on record, with temperatures rising 1.95C above average.

Keep Reading
The Planet