Draught Operations > System Maintenance and Cleaning > Detailed Recommendations
This section includes the following topics:
Cleaning Frequency and Tasks
Cleaning Solutions and Their Usage
Cleaning Methods and Procedures
The following sections detail the committee’s recommendations on draught line cleaning. We begin with the basic issue of tasks and their frequency then move into the more involved questions of cleaning solutions and procedures. The final pages of this chapter detail the procedures for electric pump and pressure pot cleaning.
Cleaning Frequency and Tasks
- Every two weeks (14 days)
- Quarterly (every three months)
- Draught lines should be de-stoned quarterly with an acid line cleaning chemical or a strong chelator in addition to the regular caustic cleaning. (The committee is working with brewing industry researchers to complete further studies on line-cleaning chemistry, including additives such as EDTA.)
- All FOB-stop devices (a.k.a. beer savers, foam detectors) should be completely disassembled and hand detailed (cleaned).
- All couplers should be completely disassembled and detailed.
Cleaning Solutions and Their Usage
Caustic-Based Cleaning Chemistry
- Caustic chemicals remove organic material from the interior of the draught line, hardware and fittings. The removal of this buildup prevents growth of beer-spoiling bacteria such as lactobacillus, pediococcus and pectinatus.
- Use a caustic cleaner specifically designed for draught line cleaning that uses either sodium hydroxide, potassium hydroxide or a combination of both.
- Some caustic line cleaning solutions add EDTA or another chelating agent to help remove calcium oxalate (beer stone) from draught lines.
- Never use solutions that contain any amount of chlorine for line cleaning.
- Based on brewery testing, we recommend that caustic line cleaning solution be mixed to a solution strength of at least 2%. A 3% caustic solution is more appropriate for lines more than 7 years old or for any line that imparts a flavor change to the beer served from it.
- Mix caustic solution with water warmed to a temperature between 80º - 125ºF.
- Caustic cleaner must remain in contact with the draught line for at least:
- 15 minutes when solution is being re-circulated, and
- 20 minutes for static, or pressure pot cleaning.
Acid Chemical
- Acid line cleaner removes inorganic materials such as calcium oxalate (beer stone) and calcium carbonate (water stone) from the interior of the draught line, hardware and fittings.
- EDTA or another chelating agent added to the regular caustic cleaning solution may reduce calcium oxalate buildup in draught lines and may decrease the need to clean regularly with an acid-based cleaner.
- Acid-based line cleaners suitable for draught line cleaning contain solutions of phosphoric acid.
- Some acid-based cleaners use acids that can harm your draught equipment:
- Hydrochloric acid corrodes to stainless steel and should not be used for cleaning draught lines.
- Nitric acid is not compatible with nylon products, including some commonly used draught line tubing, and should not be used for cleaning draught lines.
- Mix acid line cleaner to the solution strength recommended by the manufacturer.
- Mix acid line cleaner with water warmed to a temperature between 80º -125ºF.
- Acid solution must remain in contact with the draught line for at least:
- 15 minutes when solution is being re-circulated, or
- 20 minutes for static, or pressure pot cleaning.
Water Rinsing
- Always flush draught lines with fresh water before pumping chemical into the line.
- Always flush draught lines with water after using any chemical solution (caustic and acid).
- Continue water flushing until:
- No solid matter appears in the rinse water.
- No chemical residue remains in the draught line.
- Confirm chemical removal by testing the solution with pH strips or a pH meter.
- Before beginning the rinse, draw a reference sample of tap water and test its pH.
- During rinsing test the rinse water exiting the draught system periodically.
- When the pH of the rinse water matches that of the tap water, the chemical is fully flushed out.
- Chemical solution must never be flushed from draught lines with beer.
Cleaning Methods and Procedures
To be effective, cleaning solutions need to reach every inch of beer line and every nook and cranny of the connectors and hardware. You can hand clean some items like couplers and faucets, but most of the system must be reached by fluid flowing through the beer lines. The industry currently uses two cleaning procedures for beer lines: re-circulation by electric pump and static or pressure pot cleaning.
Electric pump re-circulation improves cleaning efficiency by constantly moving the cleaning solution through the beer lines through the cleaning period. You can use this method on all draught systems and it is the preferred approach for nearly all long-draw systems.
Key considerations in setting up an electric pump cleaning:
- The chemical flow should be the reverse of the beer flow wherever possible.
- Configure cleaning loops to achieve a flow rate of 2 gallons per minute, or approximately twice the flow rate for beer.
- The flow rate can be controlled by:
- Minimizing the number of draught lines cleaned at one time.
- Increasing the size of the pump used.
- Assess the flow rate by filling a standard 60 oz. beer pitcher with the cleaning solution outlet. At 2 gallons per minute it fills in 15 seconds or less.
- The pressure on the draught lines during re-circulation should never exceed 60 psi.
- Under these conditions, chemical solution should re-circulate for a minimum of 15 minutes.
Static or pressure pot cleaning offers an alternative method to clean runs of less than 15 ft. This requires 20 minutes of contact time with the cleaning solutions to make up for the lack of circulation.
The remainder of this chapter covers use of these cleaning methods, starting with setup and proceeding to the detailed steps for each procedure.
Before You Start
Regardless of your cleaning methods, some system designs require specific attention before you begin cleaning. Here’s a list of items to check and consider.
- On glycol-chilled systems, the glycol chiller should be shut off where possible to maintain solution temperature during cleaning. Failure to do so compromises cleaning effectiveness and may cause cleaning solution or rinse water to freeze in the lines.
- In pneumatic beer pump systems:
- Turn off the gas supply to the pumps.
- On the line(s) to be backflushed, set the pump valve orientation to “Backflush.” Pumps that lack a “backflush” option may be damaged by cleaning and should be cleaned using a different method.
- All legs in ‘split lines’ (lines that are ‘teed’ in the cooler or under the bar to feed more than one faucet from a single keg) must be cleaned as completely separate draught lines.
Re-circulation-Electric Pump Cleaning Step-By-Step Procedure:
1. Begin by connecting two keg couplers with a cleaning coupler. (Do not engage the couplers.)
- If cleaning four lines, connect a second set of lines with another cleaning coupler, creating a second ‘Loop.’ Cleaning more than four lines at once is not recommended, as it will be difficult to achieve the proper chemical flow rate.
- To clean the lines and couplers used for series kegs, connect the couplers attached to the gas lines and place series caps with check ball lifters on all other couplers.
2. On the corresponding lines at the bar, remove both faucets from their shanks.
- When cleaning two lines, attach the ‘Out’ hose from the pump to one shank and a drain hose or spare faucet to the other shank.
- When cleaning four lines, attach the ‘Out’ hose from the pump to one shank, connect the other shank in the loop to a shank in the second loop with a ‘jumper’ hose and attach a drain hose or spare faucet to the remaining shank in the second loop.
- When cleaning four lines, ensure that the drain hose and ‘Out’ hose from the pump are not on the same coupler “loop.”
3. Fill a bucket (“Water Bucket”) with warm water and place the ‘In’ hose into the water.
- Turn pump on and flush beer into a second bucket (“Chemical Bucket”) until the line runs clear with water.
- Shut pump off and discard the flushed beer.
4. Turn pump back on allowing warm water to run into the clean Chemical Bucket.
- Measure the flow rate of the liquid by filling a beer pitcher or some container with a known volume. Flow rate should be a minimum of 2 gallons (256 oz.) per minute.
- If cleaning is configured for four lines and flow rate is too slow, remove the jumpers and clean each pair of lines separately.
- Allow bucket to fill with just enough water to cover the inlet hose of the pump.
- Add the appropriate amount of line cleaning chemical to achieve 2-3% caustic in solution based on age and condition of beer line.
5. Remove the ‘In’ hose from the Water Bucket and place into the Chemical Bucket.
- There should now be a closed loop.
- Water should be draining into the same bucket that the pump is pulling from.
6. Allow solution to re-circulate for a minimum of 15 minutes.
- While waiting, clean your faucets.
- Fill Water Bucket with cold water.
7. Begin your rinse by removing the ‘In’ hose from Chemical Bucket and placing it into the Water Bucket (filled with cold water).
8. Continue pumping cold water from the Water Bucket into the Chemical Bucket (shutting off pump and dumping Chemical Bucket as needed) until all chemical has been pushed out of the draught lines and there is no solid matter in the rinse water.
9. Finish up by shutting off the pump, detaching the cleaning coupler, and replacing the faucets.
When Finished
- Be sure to return all system components to their original functional settings; i.e., turn glycol pumps back on, turn on gas supply to pneumatic beer pumps, etc.
Static – Pressure Pot Step-By-Step Procedure:
1. Fill the cleaning canister with clean water.
2. Untap the keg and tap the cleaning canister. Engage the tapping device.
- When cleaning series kegs, connect the tapping devices attached to the gas lines and place series caps on all other tapping devices.
3. Open faucet until the beer is flushed out and clear water is pouring.
4. Untap the canister and fill the canister with cleaning chemical mixed to the appropriate strength to achieve 2-3% caustic in solution based on age and condition of beer line.
5. Tap the canister again.
6. Open the faucet until the water is flushed out and chemical solution is pouring from the faucet.
7. Shut off the faucet and untap the canister.
- If the system is driven with pneumatic beer pumps, shut off the gas supply to the pumps to turn them off.
8. Remove the faucet and clean.
9. Replace faucet and retap the canister.
10. Pull through solution again to replenish the contents of the draught line. Chemical should be replenished at least twice during the cleaning process.
11. Allow to soak a total of 20 minutes.
12. Untap canister, empty and rinse.
13. Fill the canister with clean, cold water and retap.
14. Open the faucet and rinse until all chemical has been flushed out and there is no solid matter in the rinse water.
15. Finish by untapping the canister, retapping the keg and pouring beer until it dispenses clear.
When Finished
- Be sure to return all system components to their original functional settings; i.e., turn glycol pumps back on, turn on gas supply to pneumatic beer pumps, etc.
