Today is St Patrick’s Day and what beer is more quintessentially “Irish” than a Guinness?
If you’re celebrating with a bottle or a can of this Irish dry stout, you may notice the clink-clank of a tiny object rattling around the inside.
That little gadget is called a “widget,” and you should be thankful for it. It’s making your beer taste like it was just poured fresh from the tap.
Business Insider explains how.
In cans of Guinness, the widget is a hollow, spherical piece of plastic with a tiny hole in it. As you can see in this photo (right), it looks like a little ping pong ball.
In bottles with widgets, the device looks more like a three-inch-long rocket (pictured below).
During the canning process, brewers add pressurized nitrogen to the brew, which trickles into the hole along with a little bit of beer. The entire can is then pressurized.
When you open the can, the pressure inside drops to equalize with the pressure in the room. But the pressure inside the widget is still much higher than the pressure in the beer around it, since the gas can escape only through a tiny hole. That makes the nitrogen inside the widget squirt into the beer like a jet. This blast creates a burst of tiny nitrogen bubbles that rise to the top of beer, giving it a thick, creamy head like the one you’d get from a tap.
Guinness brewers first patented the idea of the widget in 1969, but it wasn’t until 20 years later that they released their first-generation widget, which was a flattened sphere that sat at the bottom of the can.
This little piece of plastic did its job well when serving the beer cold, but when served warm, the beer exploded everywhere after the can was cracked open.
So in 1997, Guinness released the floating, spherical widget you can see in cans today — which they call the “Smoothifier” — to fix this problem.
Breweries typically use carbon dioxide to give a beer its quintessential bitter fizz, but a drink like Guinness calls for a sweeter, silkier experience.
So brewmasters infuse the ale with nitrogen rather than with carbon dioxide, since nitrogen bubbles are smaller than CO 2 bubbles. The resulting head and taste is smoother and more delicate.
Nitrogen gas also doesn’t easily dissolve in water, so when you crack open a beer, most of the gas is released into the air, but the foamy bubbles in the head still remain. This — along with the smaller bubbles — gives the brew a thicker, more velvety “mouthfeel” without the acidic bite of carbonation with CO 2.
Because of the fleeting nature of nitrogen gas in liquid, it’s hard to maintain tasty levels of the gas in packaged beers once you open them.
“With nitrogen, you would require way higher (and dangerous) levels of pressure, and still loose plenty of nitrogen (and beer due to foaming) during packaging,” Xavier Jirau, scientific advisor of the homebrew club The Brewminaries, previously told Tech Insider via email. “In order to deal with this issue, brewers got little creative, and there is where Guinness plastic widgets come into play.”
The popularity of widgets have caught on since Guinness introduced them in the late 80s. Other beers such as Old Speckled Hen, Young’s Double Chocolate Stout, Murphy’s Stout, and Boddingtons Pub Ale all have widgets in their cans.
