Why Do Bubbles in Guinness Sink? An Exploration of the Surprising Phenomenon

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In summary, the bubbles in beer sink because of a drag force, which is caused by the current flowing down in the beer. This phenomenon is not unique to Guinness, but can be seen in most draught beers. Similar effects can also be observed with raisins in champagne. The explanation for this can be found in a mathematical model developed by researchers at Stanford and Edinburgh.
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denni89627
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How is it that the bubbles in my favorite beverage sink, unlike any other beer. After a couple minutes of research I found that the bubbles rise in the center of the pint glass but they fall along the edges which is what you see. I understand this principle with heat convection, but not with bubbles! What's going on here?

All wrong answers owe me a fresh pint. (for experimental purposes):rofl:
 
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Why do raisons do the same thing when champagne is poured into a glass with raisons in it?
 
  • #3
Yeah but raisins are heavier than the champagne...
The bubbles seem to go down way after the pour, when i can't imagine there is still that much turbulence in the beer.
 
  • #4
If bubbles rise to the top it creates a current moving up in the beer. For there to be a current going up there must be an equal current flowing down.
 
  • #5
here is a page by the group in Stanford who along with researchers in Edinburgh who did the experimental work which
a) demonstrates that the bubbles really do go down due to a drag force as mentioned by GOD_AM.
b) links to an article to the researcher who devised the mathmatical model explain the mechanism involved.

what i think is great is that this is not a property of guiness inherently, it is a property of any draught fow beers... which i always take an oportunity to order just because most tend to be tasty and are so much fun to watch...

so here is the link without further ado:
http://www.stanford.edu/group/Zarelab/guinness/index.html" [Broken]
 
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1. Why do Guinness bubbles sink?

The bubbles in Guinness beer are made up of nitrogen gas, which is less dense than carbon dioxide gas found in most other beers. This causes the bubbles to rise initially, but they eventually sink due to the higher density of the liquid compared to the gas.

2. Is the sinking of Guinness bubbles unique to this beer?

No, the sinking of bubbles is not unique to Guinness. Other beers that use a mix of nitrogen and carbon dioxide, such as stouts and porters, may also have sinking bubbles. However, the unique combination of ingredients and brewing process in Guinness makes the sinking bubbles more pronounced.

3. Can the sinking bubbles be affected by temperature?

Yes, the temperature of the beer can affect the size and movement of the bubbles. Colder beer will have smaller bubbles, which may make the sinking less noticeable. Warmer beer may have larger bubbles that rise more slowly, making the sinking more noticeable.

4. Does the type of glassware used for serving Guinness affect the sinking bubbles?

Yes, the shape and size of the glass can impact the sinking bubbles. The traditional Guinness pint glass, also known as a tulip glass, is designed to enhance the sinking bubbles and create a creamy head on the beer. Other glass shapes may not have the same effect.

5. Are the sinking bubbles in Guinness a sign of quality or freshness?

No, the sinking bubbles in Guinness are not an indication of quality or freshness. While some may argue that the sinking bubbles are a desirable characteristic of the beer, they do not affect the taste or quality of the beer. The freshness of Guinness can be determined by checking the expiration date on the bottle or keg.

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