Whether it is a home bar or you run a busy pub, ensuring the correct pressure for each of your drafts is a critical task. There are many contending factors to consider when adjusting your systems, and poorly pressured drinks can lead to disappointed customers, returned drinks and wasted money.
As gas cylinder suppliers, we want to help you ensure that every drink you pour is of the best quality and offers cool refreshments for all your customers. We will cover the correct CO2 pressure levels for various beverages and all the issues that may affect your system’s pressure.
Why Is CO2 the Best Gas for Drafts?
In a draft beer system, CO2 gas cylinders are just one essential component of producing great-tasting beer. CO2 is the best gas for assisting in dispensing beers, and at constant pressure, CO2 displaces alcohol in the barrel as you empty the keg, keeping the drinks carbonated and refreshing. Allowing a barrel to fill with oxygen can change the beer’s taste and be harmful to the beer. CO2 is naturally produced during fermentation, making it the best gas to keep the pressure right. Lack of CO2 will offer flat drinks, and you will find customers returning their drinks out of disappointment, which can be very costly to your business.
What Happens if the Pressure Isn’t Right in the Barrel?
A full gas cylinder has approximately 800 PSI which is far too high for dispensing drinks, which is why you will require a CO2 regulator, which will control the amount of pressure to the barrel needed for dispensing. If the pressure of the barrel is too low, it will lead to under-carbonated beers and drinks, which spoils the beer. Signs that the pressure is too low are as follows;
Lack of bubbles when poured
Looks like juice
Tastes flat
Alternatively, too much pressure can spoil the perfect pint and create a lot of waste. This results in too much CO2 trying to escape and less beer being dispensed. These are the signs that your draft beer system is over-pressurised;
Too much foam
Tastes acidic
Smells off
It feels too carbonated (much like carbonated water)
These can also signal that the barrel is nearly finished, and you may need to replace the keg.
What Is the Correct CO2 Pressure for a Draft Beer System?
The ideal pressure for your beer will depend on the type of beer you wish to dispense. There are also many factors which can fluctuate this and must be considered.
Different Drinks and the Required Pressures
Most ales (including pale ales, IPAs, ambers, etc.) from a brewery with a carbonation volume of about 2.1 to 2.6 require a set regulator from about 7 to 13 psi. For lagers, a regulator set between 10 and 14 psi works best. Continental and light pilsners need slightly higher CO2 regulator settings, from 11 to 16 psi. Wheat beers, Belgian beers, and common American sours are generally the most carbonated beers, requiring about 15 to 20 psi. Stouts should be poured with beer gas and a stout faucet, using a nitrogen regulator at about 35 to 38 psi.
Factors Which Affect the Pressure
Three primary considerations may be calculated to achieve the perfect pint.
The length of the beer line – If you are unsure of the length of your beer line, you can measure the line from your shank to your coupler, and you will need to measure this in feet to help you achieve the correct calculations for achieving the suitable pressure.
The line resistance – Every foot of the beer line has an average line resistance. The smaller the inside diameter of the line, the more resistance and the larger the diameter, the less resistance. Below is the table to help you determine the line resistance of your draft system. There are usually two common types of lines, as you can see below;
For example, if your beer line from the tower to your keg measures 5 feet and your beer line is 3/16″ Inside Diameter. Multiply the length (5 Feet) X Line Resistance from the chart above (2.20 lb), which will result in the Line Resistance being 11 lb.
Gravity – The rise and fall within your draft beer system will determine your system’s gravity. It is measured between the two horizontal planes of your system: the centre of the keg and your faucet. For each foot of gravity in your system, a value of .45 PSI will need to be applied. You can round this to .5 PSI to make this calculation easier.
For example, if your faucet is 2 feet above your keg, your keg is 2 feet high. Add your faucet height (2 feet) + you keg height / 2 (1 foot). This would mean your gravity is 3 feet
In the final calculation, you must multiply the gravity by .5 PSI. We will walk you through this in the next step.
To help find the ideal pressure, you take the three calculations from the above factors and use the below formula;
Pressure = (Length of Beer Line (in feet) x Line Resistance) + (Gravity x .05)
For example, if your beer line length is 5 feet, the line resistance per foot is 2.2lb, and your gravity is 3 feet, the ideal pressure is 12.5 lb.
Getting the Right CO2
If you’re searching for a more cost-effective cellar gas solution for your business, no matter how big or small it might be, we can offer you quality gas cylinders at affordable prices. We even stock home bar gas for domestic setups. Our high-quality, mixed beer gas can help to improve the taste of beer, extend the life of your customer’s favourite draught beers and improve the overall presentation.
We stock a range of sizes from 6.35kg – 50L for every need of business or bars. You can order our bottled CO2 online or contact us directly for more regular and contractual requirements.
