A close up of a pint of Guinness with the caption 'Is Guinness Carbonated?'

Is Guinness Carbonated? (And How Much Does It Have?)

Although Guinness started its life as a porter, nowadays, it is a traditional Irish stout beer, drunk all over the world. It has been brewed in St. James’ Gate in Dublin since 1759 and thus has had plenty of time to create a large following. 

Though the flavor of this beer is one that is loved by many, and the color eye-catching, it is the carbonation that causes many to ask questions. As Guinness is more creamy than traditionally ‘fizzy’, is it even carbonated at all?

Guinness, just like most beers, is carbonated. As it is stout it has less carbonation than regular lagers. Like many other stouts, it is also carbonated using a mixture of CO2 and nitrogen, creating smaller bubbles and giving a creamy mouthfeel, rather than a fizzy one. 

If you’re looking for a more detailed explanation about Guinness’ carbonation and process, as well as if it causes bloating, continue reading! 

Is Guinness Carbonated? (Explained)

All beer is carbonated, including Guinness. Carbonation is really just a fancy word for gasses in liquid. In order to keep the gas inside the beer, the liquid needs to be pressurized. When this pressure is released, either when the bottle or can is opened, or when poured from a keg, the gasses surge upwards, causing bubbles.  

Guinness uses a mixture of natural and forced carbonation, however, the forced carbonation is what makes the liquid special. Instead of carbon dioxide, or CO2, Guinness uses nitrogen. This creates smaller bubbles and a creamier mouthfeel, which means it doesn’t have the ‘fizzy’ experience most other beers have. More information about the difference between natural and forced carbonation, you’ll find below. 

Carbonation in beer is the result of two processes; natural and forced carbonation. The amount of gas within a beer causes it to be more or less carbonated. 

Natural carbonation is, as the name suggests, a natural result of the brewing process. In this process, the sugars in the barley and potentially other grains are eaten by the yeast during fermentation. This causes alcohol to form, as well as the yeast to release CO2 gasses, which end up carbonating the beer. 

However, most natural carbonation is released during the brewing process. Only some of it is kept using one of two ways. One, it can be poured into holding vessels before fermentation is completed. Two, it is bottled when fermentation is complete but left unfiltered. The yeast is thus left in the beer, and before sealing a small amount of sugar is added. This basically causes a second fermentation in which the yeast eats the sugar and causes carbonation. 

Forced carbonation is added after the fermentation process. The beer is allowed to fully ferment, after which the brewers pump carbon dioxide, or in Guinness’ case, nitrogen into the keg afterward. 

How Is Guinness Carbonated? 

The hype around Guinness’ carbonation started in 1951 when Michael Ash joined Guinness. He was the one to revolutionize the way Guinness is served. Wanting to serve Guinness in draught form, he figured the best way to do this was by using a nitrogen/co2 mixture. Most beer on draught is carbonated using only CO2, but nitrogen creates smaller bubbles. Guinness chose to go for a mixture of 75% nitrogen and 25% CO2. This creates a creamier and smoother mouthfeel, as well as the ‘surge and settle’ effect.

This effect describes the way Guinness behaves when it is poured. First, it produces many bubbles that, surprisingly, travel down instead of up. Guinness recommends pouring an almost full pint, then waiting exactly 119.53 seconds before topping it up. During these almost two minutes, the beer settles and creates the perfect foam head. 

Once this was proven to work and loved in pubs across the country, they wanted to recreate the effect in cans. The result was the use of the widget; a small, nitrogen-filled ball that is placed inside the can. When you open a bottle of Guinness, the ball releases the nitrogen and provides you with a similar experience as a pint of draught Guinness. 

However, this surge and settle effect is as much science as it is marketing. You see, it only works using a special tulip-shaped Guinness glass, as the grooves in this push the bubbles down instead of up, as you would expect with a normal pint. This downward movement is what causes the surge effect. A normal glass wouldn’t do this, or at least not as much as the tulip-shaped one. 

So, the nitrogen needing to settle is in part a marketing gimmick. After all, there are several other beers ‘on nitro’ available nowadays, and none of them need almost two minutes to settle. 

By making you wait a little longer for your pint, Guinness creates a different experience that is more memorable than other beers. But, if you’re not in the mood to wait, a martini glass is apparently the best way to get the bubbles to settle quickly, according to mathematician William Lee. 

Why Is Guinness Less Carbonated Than Other Beers?

Guinness uses a mixture of carbon dioxide and nitrogen to carbonate their beer. This isn’t particularly special anymore – most stouts are carbonated using this mixture. 

The mixture causes smaller bubbles to be generated, which means you don’t get the same fizziness you would with a standard American lager. Instead, it provides a creamy mouthfeel, making it feel like it isn’t carbonated, or at least not as much as other beers. 

Apart from stouts, there are some beers that are less carbonated, such as barleywine, which is a strong English ale and is maltier rather than hoppy, or Sahti beer, a Finnish farmhouse ale. 

There is only one modern style that can be served uncarbonated, which is (unblended) lambic, a Belgian ale.  

This beer is rather special, as the fermentation isn’t caused by the brewer’s careful selection of yeast. Instead, the wort is just left out in the open, waiting for the environment’s natural microorganisms to ferment it. This creates a beer that varies in taste. As it is left out in the open, the natural carbonation is released and not bottled, leaving you with an uncarbonated beer. 

Does Guinness Cause Bloat? 

Drinking Guinness can cause bloating, as a result of the gas inside the drink as well as the alcohol. 

Bloating can be caused by several different factors.

For beer, the most obvious reason it can cause you to bloat is carbonation. As explained, carbonation is really just gasses that are trapped inside the liquid. When you drink the beer, the gasses also enter your body, causing your stomach to puff out. This is also the reason you might find yourself burping a lot after drinking beer. 

Another reason beer causes bloating is alcohol. This is essentially just a poison that causes inflammation inside the body, including the digestive system. It swells up and produces more acid than it normally does, causing bloating. 

Lastly, there is the fact that drinking alcohol makes you dehydrated. This makes your body try to hold on to as much water as possible, resulting in a swollen stomach, as well as a puffy face, hands etcetera. 

As Guinness has both carbonation and alcohol, it causes bloating.