In order for beer to go from its keg to your glass it is pushed through a line using Carbon Dioxide (CO2). The majority of bars and restaurants use a blend known as G-Mix or Beer Gas, consisting of 25% CO2 and 75% Nitrogen. The problem is this blend was created to dispense Nitrogen-infused beers like Guinness Stout and when applied to regularly carbonated beers it can negatively affect them.
Why This Happens
The on-going carbonation of beer is dictated by several factors including temperature and pressure. These variables help balance the continuous dance between the CO2 dissolved in the beer (carbonation) and the un-dissolved CO2 inside the keg itself (called headspace). When this delicate balance is off two things happen: gas escapes from the beer into the headspace creating flat beer or non-saluted gas from the headspace is absorbed into the beer creating over carbonated beer. When using the 25/75 G-Mix blend, you don’t possess enough carbon dioxide to hold the pressure required in order to maintain this balance and the resulting loss of gas creates flat beer. In fact, the amount of psi required to re-balance this solution would exceed the limits of the equipment itself.
What the Heck Does Any of This Mean?
The known universe does not possess a draught system using G-Mix that can keep beer delicious for any extended amount of time. That’s why people who know way more about beer and science then both of us oppose the use of 25/75 gas for pouring beer.
Ok, Thanks for Making that Make Sense but How is BBD’s Different?
We use 100% CO2 to dispense our beer, additionally; we use a direct-draw system where the keg is located directly under the tap. This means beer isn’t sitting in a long tube behind a wall, sometimes at uncontrolled temperatures, waiting for you to order it.
Wow, you guys are serious. Is there anything else?
There is actually, there is a difference between clean glassware and ‘beer-clean’ glassware. Most industrial dishwashers and detergents leave a thin film of soap, fats and oils in the glass that destroy the foam found in beer. A ‘beer clean’ glass forms a proper foam head and during consumption allows ‘lacing’ – basically a pattern of foam that clings to the glass as you consume the beer.
How do we know you’re not just making this up?
You don’t have to believe us, all this information comes directly from The Brewer’s Association, an organization of 1700+ breweries, and their study on Draught Quality. And if you don’t want to believe them…
When people talk of nitro, it’s a reference to the type of gas used in the carbonation process. It means the difference between the creamier nitrogen beers (N2) and their lively, prickly CO2 counterparts. A typical nitrogenated beer contains about 70 percent nitrogen and 30 percent carbon dioxide. Nitrogen is largely insoluble in liquid, which is what contributes to the thick mouth feel. Mix this with our direct draw lines and you can taste the noticeable difference between a regular CO2 beer and it’s N2 version.