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.

Beer syrup may not be the go-to ingredient in your home bar, but it's one of those brilliant tricks that bartenders have up their sleeves. According to Berger, "Guinness Draught is not originally ...

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.

The same system is used in Guinness Draught bottles, only they use a plastic rocket-shaped widget. It allows you to have an authentic Guinness pour away from the pub. *Originally published in 2016.

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.

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.