In the past few decades, Guinness revolutionized both draft beer systems and how stouts are canned. The key? Nitrogen, and a modified ping pong ball.

Many stouts, especially a beer like Guinness Draught Stout, can actually quite low in alcohol (Draught is 4.2% ABV, for instance) and lower than you might think in terms of caloric content.

Making a beer syrup is one of the best way to concentrate these incredible flavors, Guinness Brand Advisor Zack Berger ...

You may think the espresso martini is pretty perfect as-is, but for beer lovers out there, a touch of Guinness Draught can take things to the next level.

A 12-ounce serving of Guinness Draught has 125 calories. By comparison, the same size serving of Budweiser has 145 calories, Heineken has 142 calories, and Samuel Adams Cream Stout has 189 calories.

Pints of Guinness Draught beer are pictured in London, on May 9, 2008. Leon Neal/AFP via Getty ... Guinness Draught was created in the late 1950’s.

The plastic ball in the Guinness can, also called a "widget," ensures the draught stout has its classic foamy head, as if it were poured from the tap.

Stout beer is a dark, creamy, often bitter ale that is consumed around the world. Guinness, a dry Irish stout, is the most widely known, but there are others that are popular.

Guinness hired the man who would change their beer into what we see today. Michael Ash, a mathematician and brewer, invented Guinness Draught and in doing so the world’s first nitro beer.

The plastic ball in the Guinness can, also called a "widget," ensures the draught stout has its classic foamy head, as if it were poured from the tap.