It's time to finally burst the bubble on brewer's gassy secrets, as Budweiser is crowned the gassiest of all beers, followed by Stella Artois and Coors Light.

As a nation, we've been drinking beer for centuries - it's almost a matter of pride, and it's a guarantee that a couple of bottles or cans are a staple across many fridges all over the UK. There's no doubt we're a boozy bunch, and that also means we can often suffer from the side effects too - and not only hangovers.

The often underappreciated annoyance of bloating, belching and feeling mildly like an overinflated balloon is also a common side effect of having a few too many beers. We've all been there, and felt terrible for it.

That's why we decided to team up with leading food scientist Dr Stuart Farrimond, to produce a first-of-its-kind study that finally reveals the gassiest beers of all. Did you know, for example, that there's an average of 2.1 pints of carbon dioxide (CO2) in a pint of beer?

Let vouchercloud guide you through Dr Farrimond's findings, and show you the gassiest beers to avoid this weekend, how much pressure is in a beer can and the consumer perceptions of fizzy beers.


What's the Gassiest Beer?

The 'King of Beers' - Budweiser - is one of the most popular mass-produced beers in the world, and even sponsors huge sporting events and organisations like the NFL - so it's no surprise that most of us have cracked open a Bud at some point in our lives. The results of this study, however, reveal that Budweiser has also been crowned the gassiest beer too, with 2.7 pints of CO2 in every pint. It's no wonder you're burping, right?

Which is the World's Gassiest Beer?
Joint second place was claimed by Stella Artois and Coors Light, with just over 2.55 pints of CO2 per pint, while Corona Extra (2.48 pints of CO2) came third.

The top 10 gassiest beers - the worst culprits when it comes to leaving you feeling heavy halfway through a night, that is - are:

1. Budweiser - 2.71 pints of CO2 per pint
=2. Stella Artois and Coors Light - 2.55 pints of CO2 per pint
4. Corona Extra - 2.48 pints of CO2 per pint
5. Bud Light - 
2.46 pints of 
CO2 per pint
6. John Smiths Bitter - 2.44 pints of 
CO2 per pint
7. Heineken - 2.39 pints of CO2 per pint
8. Pilsner Urquell - 2.32 pints of 
CO2 per pint
9. Fosters - 2.3 pints of 
CO2 per pint
10. Cobra - 2.27 pints of 
CO2 per pint

The study also shows that lagers contain more gas than ales and stouts, as the flattest beers are Hobgoblin (1.74 pints of CO2 per pint) and Fullers Pride (1.9 pints of CO2 per pint).

But, how do you get that much gas into a liquid? The gas dissolves into the liquid in much the same way that salt and sugar do. The molecules of carbon dioxide simply slide between the water molecules - this means that the volume of gas may be large, but the number of molecules is small so there is plenty of space for them to be squashed in there.


How Gassy do we Think Beers Are?

Budweiser is the most carbonated and scientifically most gassy beer, but we also wanted to find out whether this equates to the actual 'fizz' we experience when drinking.

... turns out it doesn't.

How Gassy Do We Think Beers Are?
Our panel though that the beer tasted less 'fizzy' than it actually was, giving it an average effervescence rating of just under six out of ten.

Our panel actually thought the top three 'fizziest' tasting beers were:

  1. Kronenbourg 1664 - 7/10 effervescence rating
  2. Bud Light - 6.8/10  effervescence rating
  3. Estrella Damm - 6.5/10 effervescence rating

How Much Pressure is in a Beer Can?

There is a wide range of pressure among the popular beers, ranging from 16.5psi for Hobgoblin to 40psi for canned Guinness Draft - more than double.  Putting these results in perspective, the opening of a can of Guinness releases more pressure than the opening valve of a car tyre, which is inflated at around 31-35psi.

From the research, we can see that - surprisingly - non-alcoholic lagers are the least pressurised of the beers tested, though it's fair to say Dr Farrimond was expecting something of the opposite. This is because many think that alcohol-free lagers are actually gassier than alcoholic lagers, and these findings show something to the opposite.

How Much Pressure is in a Can of Beer
Dr Farrimond's explanation for this was simple:

"The frequent complaint that low-alcohol beers cause burping and bloating may be because drinkers are sober and more aware of these normal beer-drinking side-effects"

In other words, when stone-cold sober, we're more aware of our bodily functions than when we're drinking alcoholic beer - making them seem gassier than they are.


Conclusion

Our partnership with Dr Farrimond found there was a variety of different types of 'gassiness' in popular beer brands, from the CO2 per pint, the pressure in a can or bottle and finally an effervescence rating. To counter some of the common side-effects, Dr Farrimond has advised that all beers should be consumer cold - as they will be less fizzy. This is because gas bubbles form more readily at lower tempratures.


Methodology

For all experiments, multiple samples of 31 popular beer brands (including lagers and craft ales) were purchased from a leading supermarket. They were then stored without moving for 48 hours before testing at a temperature of 21 degrees.

To quantify the 'gassiness' of beer, a specialist gauge fitted with a can/lid piercing adaptor was used. This tool allows for pressure within a sealed can to be measured without opening the container, acting like a tyre pressure gauge. The tool's metal needle pierces the lid while forming a tight seal with a rubber ferrule, and the pressure within the 'headspace' is recorded. Preliminary testing of one brand (Stella Artois) in cans and bottles was udnertaken and showed that there was negligible pressure differences between the containers. Thus, beer bottles and cans can be tested fairly alongside one another.