Craig's Bubbles

Okay, I can't compete with the gerber baby, so I'll just go with my passion. Well, one of my passions, anyway. So... let's talk beer.

Beer has bubbles, typically as a result of the fermentation process. Yeast eats the sugars present in the wort, and produce two byproducts as a result: alcohol and carbon dioxide. Many beers typically add more CO2 after fermentation as part of the packaging process, because we have become accustomed to fizzy beer. However, not all beers have this type of carbonation.

Guinness Draught doesn't. Instead, it gets its bubbles from good old nitrogen. One of the properties of the nitrogen bubbles is that they're smaller and more plentiful. It's an attempt to simulate the creamy texture of a real cask conditioned stout. A beer that's been pulled up by a beer engine from a non-pressurized cask is going to come up with a foamy head and not much carbonation in the body. The cans use a nitrogen widget, but when you've got a keg system like this, you need a tank of Nitrogen (technically 75% N, 25% CO2). Each produces the same result.

It's a nice effect, and creates a nice mouth feel for the beer. It also creates this hypnotic bubbly effect after the pour, often called the Guinness cascade effect. Studies have been done as to why the bubbles seem to rush down the sides of the glass. It's because they *are* rushing down the side of the glass, while the center of the beer has a hidden column of bubbles rising to the surface.

There. Science!

Now, pardon me, I have to finish drinking the two subjects who volunteered for my photo shoot. (Remember, folks, a pint of Guinness is only 125 calories. And it's good for your heart.