Caring for glycol systems during shutdown


This comprehensive guide to caring for glycol systems and beer taps during the current crisis has been prepared by Brad Murray. Brad is the Managing Director of Liquid Connections and has 25 years in the brewing industry. He is a former Technical and Commercial Manager for Draught Beer at CUB and has written and contributed to the development of numerous draught quality, installation, service, education manuals and quality programs.


A golden opportunity to ‘deep clean’ Australian glycol dispense systems

Across Australia, venues are shutting down on-premise food and beverage operations and equipment is being cleaned and put into ‘hibernation’.

For venues serving draught beer, this is likely to include the glycol beer system which is a key feature of the Australian on-premise landscape. Glycol based beer systems are far more common here than in other draught markets.

There are technical design features built into Australian glycol beer systems not found outside this market. When it comes to matters of system cleaning and ‘hibernation’, these systems require special treatment and the following information is provided to guide brewers, drink makers and on-premise through these processes.

This guide will explain how to hibernate the beer system so that it stays healthy while the doors are shut. It will also explain why this is a unique opportunity to go further and thoroughly ‘deep clean’ these systems before shutting down.

The recommendations are underpinned by guidance from peak global brewing bodies but also very targeted to address the specific draught quality challenges that we face in Australia.

The author has also taken the opportunity to toss around some general draught beer related thoughts as we prepare for draught life to return to a ‘new normal’.

Why can’t we just give the lines a clean and close the doors?

Our glycol systems are high performance beasts that require best practice cleaning systems and processes to get the most out of them. First things first – Don’t leave the beer in the lines. Anyone who has worked with draught will understand that returning to work to a thoroughly infected beer system will end in tears. And, it could be very costly.

A simple beer line clean won’t cut it either. Australian draught cleaning systems, chemicals and processes fall short of best practice and this presents us with some significant draught quality dilemmas. These extraordinary times (and prospects of prolonged shutdowns) require some additional cleaning steps.

The good news? Upsides?

Now is the best time to not just ‘hibernate’ draught systems, but to ‘deep clean’. This is a chance to implement best practices and those who take advantage will be rewarded with better quality draught, less waste, better yields, happier drinkers and a fresh, repeatable, best practice cleaning regime to take forward.

What makes Australian systems different?

Most draught systems overseas are direct draw systems (pumped up keg fridges). Simple, bullet proof, very few fittings and ‘bug traps’ and easy to clean.

Most draught beer in Australia (perhaps 85%) is dispensed through long draw glycol systems. With these, the glycol (food grade antifreeze) and water is circulated at subzero temperatures. These glycol lines are in direct contact with the beer lines for most of the journey. The beer is kept chilled from the keg to the glass. This keeps beer fresh and the build-up of bacteria in lines is slowed.

Sounds good. What is the problem?

Firstly, our beer systems have an array of quick connect adaptors and check valves and joiners which aren’t found in systems elsewhere. These ‘beer contact points’ are unwanted bug traps.

Secondly, the perpetually icy landscape inside beer lines make effective cleaning far more difficult to achieve. And, the 24/7 helter-skelter of on-premise simply doesn’t allow these systems to be shut down for long enough to warm up sufficiently to improve cleaning efficacy.

To compound this, Australian systems are (with very few exceptions) cleaned with alkaline solutions only. This removes some organic materials but is far less effective in removing inorganic matter that builds up and clings to the inner walls of tubing and stainless steel product coils.

So, after many years of cold, alkaline only cleaning, the inner walls of beer tubes and product coils contain layers of beer stone (calcium oxalate) and water stone (calcium carbonate). These are extremely stubborn beds for bacteria to settle on (commonly Pediococcus, lactobacillus and pectinatus).

What does best practice look like?

Best practice (not currently incorporated into Australian beer system cleaning) includes:

  1. Increased temperature of the chemical solution being used.
  2. Complementing the alkaline wash with a periodic acid wash to remove stubborn biofilm.
  3. Introducing an element of ‘scrubbing’ (wherever possible) into the cleaning process.
  4. Regularly and thoroughly dismantling, cleaning and sanitising ALL ‘beer contact’ fittings.

Brewers (and other food producers) routinely implement these types of approaches in their plants. They wouldn’t be allowed to operate without doing so. But, for various reasons and despite best intentions and efforts, these cleaning practices simply aren’t happening in Australian draught beer venues. Consequently, draught systems in Australia are not as clean as they could and should be.

Why is this so important to consider now?

These devastating shutdowns present a window for a ‘deep clean’.

This is an opportunity to bring these systems back to life that hasn’t been available to Australian on-premise for many years. And, it is quite simple. But it will be extremely difficult to achieve this depth of cleaning if left until doors are opened for trading.

Is this a one off?

No, this is simply the opportunity to ‘press the reset button’. Sustainable results will require this type of program (in addition the weekly alkaline clean) at least quarterly. This is in line with recommendations from our peak international brewing bodies.

There are four key steps involved in delivering the ‘deep clean’. The detailed processes follow. But firstly, a quick general overview and a re-cap to understand why each step is crucial.

The processes outlined should only be carried out by competent and qualified people and it is always wise to engage qualified beverage system technicians and refrigeration professionals to help.

Please also pay attention to some of the key safety messages and advice highlighted throughout.

  1. Temperature increase – We are doing this to improve cleaning efficacy. For many venues, this will be the first time since system installation that the glycol system has been completely shut down for more than a few hours. If left off for a reasonable period (a few days at least), the system will warm up sufficiently to enable a better system clean. Target temperature is 25-50 degrees celsius.
  2. Alkaline clean – We are doing this (as we do every week) to remove organic deposits. The only thing that has changed is that the temperature of the system has increased (and hence, the temperature of the chemical solution running through it has increased). Again, this will improve effectiveness and remove organic materials.
  3. Component cleaning and overhaul – We are doing this because some fittings are cleaned effectively in-line, but many are not. The step is about bug traps. While the system is ‘down’, the dismantling, thorough cleaning and repair of ALL in line fittings (and backups) can be done – Couplers, adaptors, check valves, manifolds, FOBs, FOB drains, joiners and taps (i.e. all beverage ‘touch points’).
  4. Acid clean – We are doing this to break down stubborn inorganics. This is to be done after and separate from the standard alkaline chemical clean. Again, at these slightly elevated temperatures, the acid wash will very effectively break down and remove stubborn beer stone (calcium oxalate) and water stone (calcium carbonate).

Together, these 4 steps are very powerful and enhance the level of system cleanliness; Well beyond what can be achieved with a standard (one dimensional) alkaline beer line clean in normal trading times.

Again, these are all routine practices recommended by major brewers and peak bodies globally.

The Deep Clean processes in detail

An important safety messageHandling chemicals warning sign
Beverage system cleaning must only be carried out by competent personnel.
Always wear suitable protective equipment.
Only use chemicals designed for beer line cleaning.
Always adhere to manufacturer’s instructions.

1. Temperature increase

Firstly, shut down the glycol system (don’t just switch it to standby). AND shut down the refrigeration condenser running the glycol dispense systems. DON’T SHUT DOWN COLD ROOM (Unless advised to do so by your refrigeration mechanic). We recommend that this be done in consultation with refrigeration mechanic /system technician so that tanks, refrigeration units and flow and return valves are shut down correctly.

Don’t pay the power company to ice beer fonts when the doors are shut for a prolonged period. Once the glycol system has been shut down, allow the glycol in the system to warm up as much as possible* – Tanks and insulated pythons are thermally very efficient, and it will certainly take several days for the system to warm up adequately.*

*Brewers Association of America recommends 25 – 50 degrees c for best cleaning results but even modest temperature increase above normal glycol system ‘standby’ temperatures will improve cleaning effectiveness
**Use this time to have the insides of tanks, pumps and pipework cleaned.

2. Alkaline clean

There are different ‘washout systems’ but the general principles outlined below apply if you use a pressure vessel, a detergent pump or a dosing unit to pick up and dilute the detergent.

Whatever system you have, please understand it very well and Think Safety First – Always.

Alkaline clean process

  • Connect the beverage lines to the washout system.
  • Make sure all possible keg couplers and transfer leads are connected.
    • Using bypass cups/cleaning heads so that couplers and leads are cleaned ‘in line’.
  • Push any beverage completely out of the lines with the dispense gas.
  • Fill the lines with clean water – Removing the dispense gas and residual product.
  • Introduce the alkaline solution (beer line cleaner) as per manufacturers recommendations.
    • KEY POINT: If possible, aim for a water temperature of between 25-50°C.
  • Fill (‘pack’) the lines from end to end with alkaline solution. Draw the solution through taps at bar and fill all FOBs and FOB drain lines.
  • Allow the alkaline solution to sit in the lines (as per manufacturer recommendations).
  • Periodically (every twenty minutes or so) open each dispense tap briefly (for 10 seconds or so) – This moves the solution through the lines to provide some ‘scrubbing’ of the internal surfaces.
  • Flush the lines thoroughly with clean water until the pH coming from the taps matches the pH of the venue tap water.
  • Finally, push the rinse water out using the dispense gas AND
  • Turn off the gas and then allow the lines to ‘de-pressurise’ – Open the beer taps at bar.
    • This is very important so that the fittings and components can be safely removed, dismantled and cleaned.

3. Component cleaning and overhaul

Couplers and dispense taps are the entry points for bacteria. Weekly alkaline cleaning flushes some away but most fittings aren’t adequately ‘soaked’ or ‘scrubbed’ as part of the in-line cleaning process.

They require regular dismantling and deep cleaning.

Brewers Associations globally recommend that this happens at least quarterly, but this happens far less frequently in this market. Manufacturers provide exploded diagrams and service instructions and of course spare parts (O-ring, washers, springs and gaskets) to replace perished or tired parts as required. Beverage system technicians are skilled at dismantling and cleaning these parts and might be engaged to help. EVERY component that encounters draught beer should be targeted for special treatment:

  • Keg couplers and quick connect adaptors and beer line check valves.
  • FOB units (and FOB drain lines and tees).
  • Beverage distribution manifolds, adaptors and shut off valves.
  • Beer font adaptors and taps (faucets).

All components can be dismantled, soaked in a mild alkaline solution, thoroughly scrubbed, rinsed, repaired (if required) and then reassembled and reinstalled. Back up components and spares should be stored in a clean, cool, dry place.

4. Acid wash

It is imperative that the acid used is specifically designed for the purpose of cleaning draught beverage systems. AND strictly adheres to the manufacturer’s recommendations. Acid based line cleaners for draught system cleaning typically contain solutions of phosphoric acid. Don’t use other acids.

X DON’T USE hydrochloric acid as it corrodes stainless steel – The fittings and heat exchange coils.
X DON’T USE Nitric acid – It is not suitable for use in nylon beverage lines.

Never allow alkaline and acid-based cleaners to come into contact. Store them separately.

The acid wash process:

  • Fill the lines with clean water – Removing the dispense gas and residual product.
  • Introduce the acid solution (beer line cleaner) as per manufacturers recommendations.
    • KEY POINT: If possible, aim for a water temperature of between 25-50°C.
  • Fill (‘pack’) the lines from end to end with acid solution. Draw the solution through taps at bar and fill all FOBs and FOB drain lines.
  • Allow the acid solution to sit in the lines (as per manufacturer recommendations).
  • Periodically (every twenty minutes or so) open each dispense tap briefly (for 10 seconds or so) – This moves the solution through the lines to provide some ‘scrubbing’ of the internal surfaces.
  • Flush the lines thoroughly with clean water until the pH coming from the taps matches the pH of the venue tap water.
  • Finally, push the rinse water out using the dispense gas AND
  • Leave the lines pressurised with dispense gas to minimize bacterial build up.

A few other practical shut down tips:

  • Gas system service – Before turning off the gas, check the system for leaks and performance. Make sure the regulators are delivering the pressure they should be. i.e. To maintain correct carbonation of the beverage they connect to and to propel that product from keg to glass.
    • Engage a competent beer system technician if required.
  • Turn off the gas – Eliminate risk of leaks and possible CO₂ hazards when trading starts up again.
  • Refrigeration – Mechanics can advise on specific processes to shut down and clean condensors, evaporators and fans.
  • Tank clean – Most glycol tanks and ice bank cooler tanks will not have been cleaned since installation (5, 10, 20 years and more for some). As they warm up, they will require disinfecting and sanitation. Qualified technicians can advise on the best way to pump out and store glycol solutions and how to best drain ice bank baths and clean them.
  • Glass washer clean and service – Thoroughly clean internal walls and spray arms. Make sure detergent pick up is working and wash and rinse cycle temperatures are as per manufacturers guidelines.
  • On and under-counter – Heat exchangers and insulation under bars are known hot spots for mould and bacteria and dreaded ‘bar flies. This is a great opportunity to safely disinfect and sanitise these areas. Drain lines from drip trays might be upgraded at this time.
  • Cool room – With no kegs on the floor, this is the perfect time to scrub floors, walls fixtures and ceilings.

The beer system is now restored to former glories and essentially ready to ‘hibernate’. And, when you return to prepare for re-opening, you will arrive back to a very healthy beer system.

The task ahead (at least regarding draught) will be less daunting, less costly and less time consuming.

The system will be ready to perform – To deliver premium quality draught and optimized profitability.

If shutdowns are prolonged, these procedures (excluding dismantling of fittings) should be carried out every four weeks. During normal trading times, this full program should be carried out at least quarterly (in addition to the weekly alkaline clean).

Upon return:

  • Rinse and clean fittings stored away that need to be used.
  • Spray all ‘beer contact points’, coupler bases, tap nozzles with ethanol-based sanitizer.
  • Run a mild alkaline solution through the lines.
    • Even the cleanest systems will have built up some bacteria while shutdown.
  • Rinse the system thoroughly.
  • Tap fresh kegs and push water from the lines with the fresh beer.
  • Re-fill glycol tanks with stored / fresh glycol – Check glycol levels and concentrations.
  • Re-start the glycol system and the refrigeration system – Engage a refrigeration mechanic.
    • REMEMBER – The system will take longer than normal to chill – From ambient to sub-zero.
  • Once operating temperature is reached, draw off any beer fob through taps.

Finally, dazzle your customers with fresh draught beer.

Time to ponder?

Some might find time through this disruption to reflect – ‘From keg to glass’. So, a few thoughts and hopefully discussion starters for draught fanatics.

Kegs – Now that the fleet of kegs is coming home for a while:

  • How many kegs are in the fleet?
  • Is it time to document and better manage/track the assets?
  • Should we consider different keg sizes /styles?
  • Is the keg logistic approach right for the next phase?
  • Time for keg chimb repairs/replacement of damaged spears / valves?

Draught QA and QC

  • What are keg complaint and keg return data telling us?
  • Are draught quality processes and systems adequate?
  • Time to invest in better laboratory instruments?
  • Keg cleaning, sanitation and keg filling processes?
  • Preventative programmes for kegs, spears and valves?

Distribution and Execution

  • Chasing tap points vs. Aligning with ‘the right’ venues?
  • Unpasteurized beers in venues with no draught cool rooms?
  • Venue culture/fit? ‘Draught focus’?
  • Can our customers properly clean the system?
  • Sales training – Do our reps and roadies ‘get’ draught?
  • Brands – How do you want your draught brands to be presented to your draught beer drinkers? – Perfect pour guides, branding, logos, decals, handles, glassware selection, flavour profiles, staff training and empowerment.

Food for thought on beer system cleaning

In most draught beer markets, the beer system is cleaned (and often maintained) by the brewer/s or their contractor. This is not the case in Australia. Here, we expect venues to take charge and be willing and able (day in day out) to implement best practice cleaning and maintenance programmes. Is this a reasonable expectation? The difficult reality is that many venues will do their very best. And, unfortunately, many more can’t or won’t.

Finally, we don’t know when On-Premise doors will re-open. When they do it is fair to assume that it won’t be business as usual. A different drinker will emerge from hibernation. In our own ways, we will all be a little wary and more discerning than we were when we went into our caves. But we will be craving to catch up over a well-deserved, premium quality draught or two.

I hope this has been of use and if you have any questions or thoughts, please contact me.

Best wishes through these extraordinarily challenging times.

Brad Murray
brad@liquidconnections.com.au

Disclaimer: The thoughts in this article are those of the author. All technical and safety advice is in line with peak Brewing Association guidelines. Readers should always seek their own expert advice regarding chemical selection and handling. Chemical handling and cleaning tasks of this kind should only be carried out by competent personnel.


Liquid Connections is a leading supplier of premium push fit and related fittings and tubing and clamping solutions to the drinks and water purification and filtration industries.

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