Walk into any pub and order a pint of Guinness, and you’ll witness a mesmerizing ritual. The bartender pulls the tap, fills the glass two-thirds full, then sets it aside to settle before topping it off with that iconic creamy head. But crack open a can of Guinness at home, and something magical happens without any theatrical waiting period. Pour it out, and you get that same cascading foam effect that made the beer famous.
But how is it done? It’s all thanks to a tiny little device that is affectionately known as The Widget.
Beer Engineering
In 1959, draught Guinness diverged from other beers. The pints served from the tap at the pub were charged with a combination of nitrogen gas and carbon dioxide, rather than just carbon dioxide alone. Nitrogen is less soluble in beer than carbon dioxide, and low temperatures and higher pressures are required to get it to stay in the fluid. Charging the beer in this way, and then forcing it through a tap with a restrictor plate with many fine holes, allows the pouring of a beer with small, fine bubbles. This is what gives Guinness its signature smooth, creamy texture and characteristic dense head. The lower carbon dioxide level also contributes to the flavor, removing some of the sharp taste present in regular carbonated beers.
When Guinness started using the nitrogenation method, it quickly gained popularity and became the default way to serve the draught beer. The problem was that it wasn’t initially practical to do the same for bottled Guinness. Without being poured through the fine holes of a special tap under pressure, it wasn’t possible to create the same foamy head. Bottled Guinness thus remained carbonated in the traditional manner, and it was thus very much unlike the draught beer served at the pub. The desire was to produce a better version—”bottled draught Guinness” was a term often bandied about. The company experimented with a variety of methods of serving nitrogenated Guinness from a bottle or can. It even sold some bottles with a special “initiator” syringe to generate head in select markets, but it was all too clumsy to catch on with the beer drinking public. A better solution was needed.
The modern widget was developed as the technological solution to this fundamental problem in beverage physics. Guinness tackled this challenge by essentially putting a tiny pressure vessel inside the larger pressure vessel of the can itself. The widget is a small plastic sphere, hollow inside, with a tiny hole on the surface. The widget and beer are placed inside the can on the production line. Liquid nitrogen is then added, before the can’s lid is sealed. The can is then inverted as the liquid nitrogen quickly boils off into a gas. This effectively fills the widget with gaseous nitrogen under pressure, often along with a small amount of beer. It’s a charged pressure vessel lurking inside the can itself.
The magic happens when the beverage is served. When you crack open the can, the pressure inside drops rapidly to atmospheric pressure. The nitrogen under pressure in the widget thus wants to equalize with the now lower-pressure environment outside. Thus, the nitrogen sprays out through the tiny hole with tremendous force, creating countless microscopic bubbles that act as nucleation sites for the rest of the nitrogen dissolved in the surrounding beer. As the beer is poured into a glass, a foamy head forms, mimicking the product served fresh from the tap at the local pub.
Today’s widget, first marketed in 1997, is the floating sphere type, but the original version was a little different. The original widget launched in 1989 was a flat disc, which was mounted in the bottom of the can, but fundamentally worked in the same way. However, it had a tendency to cause rapid overflowing of the beer if opened when warm. The floating spherical widget reduced this tendency, though the precise engineering reasons why aren’t openly explained by the company. The fixed widget actually had a surprise return in 2020 due to COVID-19 supply chain issues, suggesting it was still mostly fit for purpose in the brewery’s eyes.
The key to the widget’s performance is in the filling and the construction. It’s important to ensure the widget is filled with pressurized gas, hence the inversion step used in the filling process. If the pressurized nitrogen was allowed to simply sit in the empty space in the top of the can, it would just vent out on opening without making any head. The orifice size on the widget is also critical. Too large, and the pressure equalizes too quickly without creating the necessary turbulence. Too small, and insufficient gas and beer volume flows through to generate adequate nucleation. The widget as it stands today is the result of much research and development to optimize its performance.
Further different widget designs have emerged over the years. The company had mastered draught Guinness in a can, though it needed to be poured into a glass to be drank properly. The company later looked to create draught Guinness that could be drank straight from the bottle. This led to the creation of the “rocket widget.” It worked largely in the same way, but was designed to float while remaining in the correct orientation inside the neck of the bottle. Fins ensured it wouldn’t fall out of the bottle during drinking. It would charge the beer with bubbles when first opened, and continue to boost the head to a lesser degree each time the bottle was tilted for a sip.
Guinness could have left this problem unsolved. It could have remained a beautiful tap-based beer, while selling its lesser carbonated products in bottles and cans for home consumption. Instead, it innovated, finding a way to create the same creamy tap-poured experience right out of the can.
The next time you crack open a widget-equipped can and watch that mesmerizing cascade of bubbles, you’re witnessing a masterpiece of beverage engineering that took years to perfect. It’s a reminder that sometimes the most elegant engineering solutions hide in the most ordinary places, waiting for someone clever enough to recognize that a tiny plastic ball could revolutionize how we experience beer outside the pub.
But why? What’s the need for that kind of stupid, consumerist ritual? At home when I drink Żubr beer I just open a can and drink it. No need to pour it into a glass. Beer is all about alcohol and taste, not watching foam like it’s some piece of abstract art.
Nitrogen, as the article itself notes, changes the texture and flavor of the beer, compared to using carbon dioxide, but there are difficulties in having the nitrogen knocked out of solution in a reliable, repeatable manner. Being able to knock the dissolved Nitrogen out of solution in a reliable manner produces a reliable result, that result is designed to mimic the effect of a tap. This texture directly effects the flavor.
Full disclosure, however, I’ve never been a big fan of Guinness myself, but I can respect the engineering that went into replicating the (IMHO superior) texture of tapped Guinness.
Considering Zubr has a 3 star review on Untapp’d, I’m going to guess you’re less drinking for flavor, and more for effect; to each their own.
Yup. I’ve definitely noticed the effect in carbonated drinks vs nitrogen-ed drinks. Diet Coke has a sharp acidic feel. If you let the Co2 bubble off, the bite goes away. Nitro cold brew is bubbly but smooth right out of the can.
Similarly people taking acetazolamide (say for rapid altitude aclimiazation) as well as the usual diuretic effect will notice the change in carbonated beverages as it inhibits carbonic anhydrase and stops the zing on your tongue.
I’ve heard it called champagne blues.
And presumably nitrogen is not affected by this!
Wild!
https://pubmed.ncbi.nlm.nih.gov/3364458/
(DOI link gets you the full paper.)
Til that’s why lamictal (lamotrigene) does that. Had an ex taking it for antipsychotic reasons and she stopped enjoying soda.
“ Nitrogen, as the article itself notes, changes the texture and flavor of the beer”
A different brewing method and different ingredients change the texture and flavor of the beer as well. Guinness could try to make a better tasting neer that doesn’t need nitrogen, right? Hundreds of Dutch, Belgian and German breweries make beer that tastes super without nitrogen or widgets. And even with nitrogen and widgets, Guinness still tastes meh.
:D
“Beer is all about alcohol and taste” and “Żubr beer” in the same sentence, good one.
And is is not a ritual, humans taste mostly via the nose, so if you drink beer from a can/bottle you will taste it less because less air born stuff gets into your noose. You might prefer it because a beer like Żubr will simple taste worse from a glass because more of it “amazing taste” gets into your nose.
Great tasting beer is not good drinking beer, because you’ll quickly grow tired of the taste. The first pint goes down well, the second pint is okay, and the third pint you’ll be forcing down your throat.
Great drinking beer is drank cold and from the can, so it’s as odorless and tasteless as possible, almost like carbonated water with a hint of malts and hops, so you can drink several cans and still come back for more without taste fatigue.
This is why most American beers are the way they are. However, Guinness is its own beast.
You have defined the difference between someone who drinks to enjoy the flavor vs. someone who drinks just to get drunk. I prefer flavor.
Because I feel like it. Buzz off.
Call me crazy, but the bottles taste worse than the cans. Not everything needs it though. I’m guessing from another comment, Żubr seems to be like Pabst Blue Ribbon. I don’t need a widget to enjoy a cheap beer.
You’re not. If I remember correctly, bottles allow for a small amount of oxygen intake and cans do not. Clearly oxygen affects the chemistry of it all.
Not oxygen, light. Light drives chemical reactions that cause “skunking”.
This is the reason why beer bottles are usually brown or green – to absorb light.
“sTuPiD cOnSuMeRiSt RiTuAl”, you sound like such a reddit right now
The brewers would cry if they saw this. Beers are designed to be served in specific ways, that’s the purpose.
Mass market beers are designed more or less for what you do, drinking straight from the can or bottle, and light beers often work this way well enough with few changes.
Heavier beers or those with specifically controlled flavour profiles are different. Some expect to be served not only in a glass, but a specific type of beer glass and temperature, even pouring method, similar to many wines. These affect oxygenation, how acidic, basic, or smooth the drink is when it hits your tongue.
TLDR; You might be fine with anything, but for a lot of people drinking is not just about alcohol, but a hobby into it’s own. You prefer a lager, get a lager glass, and serve it at the intended temperature. Polish lager is typically meant to be served at around 5°C I think. See if you enjoy it a bit more.
You are on hackaday, there’s no way you don’t treat something in your life the same way already, make a ritual of it.
Guinness is often referred to as Meal In a Can for a reason. It’s unlike most beers, especially American beers, which are watered down to be “light”. Guinness really is its own class of beer. You can practically cut it with a knife and serve it in slices. But there’s a ton of flavor in it. Quite possibly the only beer that needs to have head.
Reading this a few streets over from where it’s made, thanks for linking to the article about the plunger and the Guinness Light, didn’t know that those were the ancestors of the widget. Unfortunately it still tastes like beer.
I’d just like to suggest the alcohol-free Guinness. It’s actually quite good, and the canned variety does indeed have a widget.
^ This. It is good!
Regular Guinness is mediocre, at best.
It’s the American Budweiser of stouts.
Drink ANY micro-brewed stout, much, much better.
Can’t imagine the kinderbeer version is worth drinking.
Some micro brews are better and some are worse, all depends on your taste.
HaHa.
alaska brewing has a good stout. better than guinness.
They have a smoked one that is fantastic
Come now. That’s not fair to water.
IMO, boring and overpriced, which is why it’s popular with both customers and bars. It’s a massive market stout with a chemical gimmick (that actually works) to make it smooth.
The article topic was a genius move and I do like nitrogenation for the flavour profile it brings, but you are fully correct in that one should drink a local microbrew if possible. If nothing else, you want to try different things and you can always laugh at the mistakes of a small brewer, likely with the producers themselves if you want.
Not being a big beer drinker myself, friends had to drag me into this culture, but it is fun and the culture is deeper than American slightly alcoholic soda products.
I was at Apple’s WWDC once. They always have a party at the end. At the party they served beers: non-alcoholic, normal and heavy beer.
Turned out the normal beer was some 2% alcohol, and the heavy beer was 5%.
Listen Apple… A proper heavy beer has between 10-12% alcohol. It tastes like tar, makes your stomach sick, makes you piss drunk already after 1 bottle, but it takes at least an hour to finish that bottle because of its taste.
Then there is the heavy beer that actually tastes good, between 8-10% alcohol.
Then we have the normal beers. Generally 5 to 6% alcohol. Pilseners and IPAs.
Then come the light beers with 2-3% alcohol.
And the alcohol-free beers, which actually have somewhere between 0 and 1% alcohol.
I do not expect to be served a pilsener if I ask for a heavy beer, period.
Ah, and yeah, I do not run around drunk and making trouble on parties. Because I drink the beer for the taste and mild alcoholic effects. If I want to be drunk and make trouble, I’ll drink a good Wodka and not have a hangover the next day.
I’ve had the “zero” alcohol Heineken and Stella. They’re pretty good too.
I have to ask, if you want a light refreshment like that with no alcohol, why drink beer at all? Just pick up soda water and flavour to your preference. Not pulling your leg, an honest question as these beers are just soda themselves.
In my case I like beer flavors, with and without alcohol. Sometimes I have to drive to and from the venue where I will spend evening. Here in Norway drink and driving is not an option, so rather than drink a overly sugary drink or water, I have a 0% beer.
0% beer usually just tastes like non-fermented malts or the pre-brew “tea” as it goes in the vat. They have a similar taste as taking a spoonful of flour and mixing it in a glass of water with some sugar and hops.
De-alcoholized beer tastes better, but it’s still flat compared to real beer. I’ve yet to find a proper non-alcoholic beer that has the proper taste, and isn’t trying to mask the lack of flavor by overloading on hops.
I’d rather have a nitrogenated cappuccino without milk or sugar than a non-alcoholic Guinness. The taste is the same, but at least I’m being honest and not pretending I’m drinking beer.
Now that is something a bit harder to come by, I’m not a fan of buying pre-made coffee, especially given the price, and bottled nitrogen prices make me want to separate it myself.
discovering i actually kind of like seltzer water led me to open my mind to a lot of these ‘hop tea’ and ‘alcohol-free beer’ sort of beverages. and if you’re desperate for a novelty like i am then you could definitely do worse! there’s even a ‘wheat soda’ that i guess is popular in india and mexico??
if i was to suggest a ‘see also’ for canned guinness with a widget, i would recommend boddingtons
Conversely there are some quite nice ales known as barley and wheat wines. They’re strong in alcohol and flavour like wines so you wouldn’t want to drink them by the pint. They’re more like a warming winter beverage.
I’m not sure how this is converse, there’s a reason winter ales exist and ales are (supposed to be) served at ~12.5°C or mulled at ~ 60°C.
Do you make these yourself? I do that (sans hop-tea, I’d rather chew pine tar), as do friends and even my parents. To satisfy your interests start collecting flavours rather than brands.
I think the foam is the thing I like the least. Would rather just drink the beer, although give me a Belgian Ale every time…
Ok, you just said you don’t like foam and that you do like Belgians at the same time?? Belgian’s signature characteristic is their effervescence.
That said, I get what you mean with a huge “head”. That’s not the point of nitrogenation, it’s the very fine bubbles that are not acidic. I would guess you like the light acidity of a Belgian, so the more neutral nature of a nitrogenated stout (any kind) might not appeal to your tastes. Have you tried a Framboise?
Great piece! Was confused at first by the definition of widget though. In a business sense, the widget has a different meaning and I was half expecting this story to be about math, and how using a generalized value somehow changed beer delivery. Like how the wooden pallet revolutionized shipping. Was a fun surprise to learn of one more definition of the word widget. Thanks for sharing
Widget basically means thingy.
Is the widget the same shape as a turnip?
as with ‘bedule’ in champagne making
In a business sense, widget is a standin for a party or whole product, that’s where the ball got it’s name too, right as that style of business speech had taken over upper management in US corporations. And just like any other corporation they didn’t change the name once it was a product.
Since you are familiar with the topic, simulate in your head a couple of the meetings that led to this outcome, it shouldn’t take long.
Guinness has also released a non widget nitrogen infused can which you use a clip on ‘nitrosurge’ device, I think it just has a pizo speaker that buzzes the nitrogen out every few seconds. You can also put a glass of Guinness in an ultrasonic cleaner with a little bit of water underneath to get the nitrogen out to make a creamy head :)
What I don’t understand is how and why the N goes into the widget rather than “simply sit[ting] in the empty space in the top of the can [which a moment before was the bottom]”.
I’d guess it does both. It fills the empty space and the widget. When you open the can, the gas in the empty space vents out right away, but that in the widget bubbles out more slowly. That’s my guess, anyway.
Thank you, I guess that’s the only way it makes sense. Your answer was helpful.
The answer “As explained twice in the writeup, the can is inverted on the filling line after the nitrogen is added. Instead of the nitrogen staying at the top of the can it travels to the bottom where the widget sits and fills it” was not helpful, not least because it doesn’t reflect that the bottom becomes the top and the top becomes the bottom, as explained once in the question.
That’s exactly how it works. To be more specific, with the van upside down after having been pressurised with nitrogen, the nitrogen immediately goes to the top, along with the empty (air filled) ball. The pressure equalises through a small hole in the ball, and a tiny amount of beer. When righted, the ball stinks to the bottom, the combination of plastic and pressurised nitrogen not being buoyant enough to stay up. When opened, the nitrogen at the top immediately escapes, and the pressure drop leads to the ball decompressing as well, but the small hole makes this a fine foaming jet, resulting in the drink foaming as desired.
“the ball stinks to the bottom”
Aha! THAT explains the smell of Guinness!
;)
As explained twice in the writeup, the can is inverted on the filling line after the nitrogen is added. Instead of the nitrogen staying at the top of the can it travels to the bottom where the widget sits and fills it.
the widget is inserted at ambient pressure. then the liquid nitrogen is added. then the cans/bottles are sealed. as the nitrogen boils off in the can, it increases the pressure, which forces nitrogen into the beer and the beer into the widget. the raised bottom in the bottle/can will keep the widget below the gas line so the boil off will force beer into it. when you open the can the sphere contents is at higher pressure and will force out the beer.
Beer is largely water. How compressible is beer?
Executive summary: Not buying it.
The beer is not compressible, but the gas inside the widget is. When the external pressure rises, the volume of gas inside the widget decreases and beer goes in. Eventually the gas is dissolved in the beer and the widget is entirely filled with liquid.
When the pressure drops, the reverse happens and the beer squirts out of the widget, through a tiny hole that causes it to foam up.
Love the artwork
So I should be hooking my nitrogen filled car tire to my keg of beer?
No, but the idea of having lightweight semi-permeable pressure vessels in tires is interesting (and not a new idea), intended to seal leaks or prevent catastrophic loss of control. Solutions have included secondary inner tubes, multichamber tires that seal depressurised sections and maintain their own capacity, foaming goo that takes up space or hardens on exposure to oxygen free flowing in the tire (mechanics hate this stuff), etc., many things.
Not „widget” – more of gadget thingy.
Imagine miniature, shallow ultrasonic cleaner with a Guinnes logo.
Less than quid in local trift store ;)
https://www.reddit.com/r/Guinness/comments/16bxcsy/ultrasonic_surger_20/
I could totally use a shallow ultrasonic cleaner, with or without
guiness logo. Wish I had your thrift stores!
What happened to all the comments on the “Estimating Celsius” article?
If you want to try real Irish beer I suggest you get some Smithwick’s.
Irelands oldest beer and far better tasting than stout.
And no plastic pats…
Indeed. Guinness isn’t really Irish either. It was devised as a tax-avoiding knockoff of London Porter.
Knew part of this, but not that it was London Porter, neat… Also weird to me as Guinness is nothing like a proper porter.
Agree completely.
Have any recommendations for a Scottish? I have n liked a couple, but many are misses for me.
You are in the business of communicating in English. Please, please, please get it right. The past participle of drink is drunk, not drank.
There’s an earlier article with the word “unphased” instead of “unfazed”. 😑
“Set phasors/fazors/fasors/fasers/fazers/phazers/phazors/phazurz on stun!”
English spelling is weird. The English language is the only language capable of having exactly the same language rules all over the world and still divide people.
i love guinness but i think the alaska brewing stout is better. i may be a bit biased, i used to live across the creek from the brewery.
How can you do an entire article about the widget without the dancing penguins?
https://www.youtube.com/watch?v=UOdGWTrTJTI
Honestly, this place is going to the dogs.
I am still awaiting my promised Guinness bar towel, dammit.
ITS A G.D. PING PONG BALL AND YOU KNOW IT. Stop with the Widget madness!
Ok. A serious comment…
What I absolutely don’t like is that it’s a plastic thingy in an aluminium can. That means that it takes an extra step in the recycling process. The plastic needs to be separated from the can first before either can be recycled.
So it makes the recycling process relatively expensive. While it should be cheaper, to incentivize recycling.
I’m sure it’s unnecessarily leading to more ‘wild’ plastic in the environment, which is not a good thing.