Brewing can be a tricky process, we all know that. But with the right knowledge, tools and equipment combined with OCD-levels of cleaning and sanitising, plus patience and a bit of luck, you will hopefully produce a great beer. But your work isn’t done there! How beer is stored and dispensed is just as important. So read on to find out if your beer lines are on point. And spare a thought for the brewers whose fate and reputation lies in the hands of pub and bar staff, who may not be as thorough as you can be after reading this article.

BEER LINES

The beer line is the tubing that connects the keg to the tap. It sounds pretty straight forward, but the beer line is more than a transport system: it actually plays a significant role in the taste and quality of the dispensed beer. 

When setting up a beer dispensing system you need to take into consideration the length and inside diameter of the beer line. To determine those measurements, you have to think about the type of beer being served and its temperature, as well as the pressure from the CO2 or nitrogen used to dispense the beer. Getting these right will help you achieve a consistent and optimal pour speed and ensure that the resulting pint maintains the integrity intended by the brewer: with the right amount of foam, at the intended carbonation level, and with the right taste and aroma characteristics. 

KEY COMPONENTS OF A BEER LINE SYSTEM

A beer line system typically includes the tubing (the beer line) that carries beer from the keg to the tap, the keg, couplers, fittings, regulators, separators/blenders, and the tap. The coupler attaches to the keg, and the regulator manages the pressure of the gas pushing the beer through one end of the tubing.

CALCULATING BEER LINE LENGTH  

Selecting the correct length is vital to ensure optimal performance of your draft beer system. Lucky for us there is a formula to determine the correct length! A commonly used equation is:

BL = (Ps - (RS x 0.5) - 1) / R

BL = Beer line length (in feet)

Ps = Pressure set on the regulator (PSI)

Rs = Rise from keg to tap (feet)

R = Resistance factor depending on the beer line diameter

Note: A longer beer line may be needed for systems with higher elevation from the keg to the tap.

CHOOSING THE IDEAL BEER LINE DIAMETER

The internal diameter (ID) of beer lines in a draft system plays a key part in controlling the flow rate, managing foam, balancing the system, and maintaining the quality and temperature of the beer. The ID dictates the resistance the beer encounters while flowing through the lines, impacting the pour and carbonation level. So getting the diameter right is essential! 

A smaller diameter creates greater resistance, which then requires higher pressure for proper beer dispensing, can create too little foam or can excessively slow down the pour. Conversely, a larger diameter reduces resistance, but a system with too little resistance will cause beer to pour too quickly, resulting in fobbing.  

Here’s an overview of common beer line sizes:

5 mm (3/16”) ID: High resistance, suitable for systems with shorter runs.

6.5 mm (1/4”) ID: A middle-ground option with moderate resistance.

9.5 mm (3/8”) ID: Offers less resistance and is suitable for longer beer lines.

The selection will also depend on factors such as the desired flow rate and the specific type of beer being served.  

MAINTAINING AND CLEANING BEER LINES

A clean beer line ensures that the beer is served with its intended flavour profile, without off-flavours or odours resulting from bacterial growth or yeast build-up. If your lines are infected you might also experience excessive foaming (‘fobbing’). Be sure to carry out regular and meticulous maintenance and cleaning on your lines to preserve the aroma and taste that you have worked so hard to perfect!

Experts recommend cleaning beer lines every week, and ideally each time you change your keg, to prevent the build-up of organic materials and mineral deposits that can lead to clogs. 

This cleaning routine should include:

Agitation: Using a cleaning solution to scrub the internal surfaces.

Flushing: Thoroughly rinsing the lines with clean water post-cleaning to remove any residual cleaner.

Chemical Contact: The type of cleaning solutions should be carefully chosen, typically involving a mix of sodium or potassium hydroxide, and they must make contact with the beer lines for the recommended duration. This process is crucial for eliminating contaminants that can compromise taste and aroma.

BALANCING A DRAFT BEER SYSTEM

To achieve an optimal pour, it’s critical to understand and adjust two key aspects of your draft system: the keg pressure settings and the beer’s carbonation levels. 

The gas pressure from the CO2 tank must match the beer’s carbonation level to avoid over-foaming or under-carbonation. An imbalance in the system can lead to either excessive foam or flat beer. To calculate this use the following equation:

Serving Pressure (psi) = Required CO2 Volumes + Temperature Factor + Elevation Factor

Factors affecting pressure include: 

Beer temperature: colder beer can hold more CO2.

Height difference between the keg and the tap: gravity affects flow rate.

IMPACT OF BEER STYLE ON SYSTEM BALANCE

Beer style significantly influences system balance; it’s crucial to tailor the serving pressure to the specific type of beer being served to preserve its character and ensure the perfect tasting experience. Different beers require specific carbonation levels, necessitating adjustments in the pressure settings. For instance, a stout may require lower carbonation levels and therefore lower serving pressure compared to a highly carbonated pilsner. Here are some carbonation levels by beer style:

Stouts and porters: Typically lower carbonation (1.6-2.0 volumes of CO2)

Ales and lagers: Moderate carbonation (2.2-2.7 volumes of CO2)

Wheat beers and Belgian ales: Higher carbonation (2.7-4.5 volumes of CO2)

TROUBLESHOOTING COMMON DRAFT SYSTEM ISSUES

In draft beer systems two common issues are excessive foaming and slow pours. Effectively addressing these concerns requires a methodical approach to identify and resolve the underlying causes.

EXCESSIVE FOAMING

This can spoil the beer experience and lead to waste. Temperature is a critical factor; beer should be stored and dispensed at the appropriate temperature for the style. If the beer is too warm, it will foam excessively. Checking the CO2 pressure is also crucial: it should be properly set - usually between 12-14 PSI for ales and lagers. Regular inspection and correct sizing of beer lines are also essential to maintain optimal resistance and minimise foaming.

SLOW POURS 

At home slow pours are tiresome; in a commercial environment they can disrupt service and frustrate customers. The issue is often caused by obstructions in the lines or the need for increased pressure. Beer lines should be regularly inspected for any blockages or kinks. And check the pressure: it might need adjustment if it is too low for the system’s demands.