KEG CLEANING STANDARDS

MINERAL WASHING/STERILIZING SEQUENCE (STEAM)

WASH HEAD

Purge out ullage beer with sterile air until clear.	3 sec.
Pre-rinse Keg with fresh or recovered water.	8 sec.
Purge out pre-rinse water with air.	5 sec.
Hot caustic or acid wash.	12 sec.
Low flow hot caustic or acid wash.	12 sec.
Purge out hot caustic or acid to recovery tank with sterile air.	6 sec.
Final rinse Keg with hot water.	12 sec.
Low flow hot water rinse.	12 sec.
Purge out hot water rinse with steam.	18 sec.
Pressurize to 20 psi with steam.	1 sec.
Release pressure from process head.	1 sec.

STERILIZE HOLD STATION

Steam

60 sec.

RACKING HEAD

Steam conn. head and Keg neck.	5 sec.
Steam pressure release from Keg.	5 sec.
Gas purge Keg.	8 sec.
Counter pressurize to 20 p.s.i.g.	2 sec.
Product fill.	50 sec.
Spear out.	1 sec.
Water scavenge and/or gas scavenge.	5 sec.

MINERAL WASHING/SANITIZING SEQUENCE

WASH HEAD

Purge out ullage beer with sterile air until clear.	3 sec.
Pre-rinse Keg with water.	8 sec.
Purge out pre-rinse water with sterile air.	5 sec.
Hot caustic or acid wash.	12 sec.
Low flow hot caustic or acid wash.	12 sec.
Purge out hot caustic or acid to recovery tank with air.	6 sec.
Final rinse Keg with sanitizer.	12 sec.
Low flow sanitizer rinse.	12 sec.
Spear out.	1 sec.
Purge head.	1 sec.

RACKING HEAD

Gas purge sanitizer from Keg.	10 sec.
Gas counter pressurize to 20 p.s.i.g.	2 sec.
Product fill.	50 sec.
Spear out.	1 sec.
Sanitizer scavenge and/or gas scavenge	4 sec.

*Chemical products generally recognized as suitable for the Keg cleaning sanitizing process may be used as recommended by supplier.

 

KEG PLANT QUALITY CONTROL CHECKS

DETERGENT TANK TITRATION

The detergent set, detergent tank(s), Quality Control checks should be made before starting and at least twice during each eight (8) hour operating shift. Adjust frequency to meet the Quality Control department “comfort level”. The acid titration level (phosphoric) should be in the range of 0.25% to maximum of 0.4% v/v and alkali titration level (caustic) in the range of 1.5 to 2.0% v/v.

KEG WATER CARRY-OVER AND TITRATION CHECKS

1) After the Keg has completed the wash head(s) sequence(s), the Keg must be allowed to continue through the sterilizing sequence and then rejected (stopped) immediately prior to commencing the racking head(s) sequence(s). When the Keg is retrieved at the discharge end of the machine, the Keg can be cooled down by placing a cold water hose over the outer surfaces (if steam is used). A Quality Control Keg coupler or funnel coupler (with the C02 and beer check valves removed) is then used to tap the Keg. The Keg must be inverted to remove the contents via the C02 port of the coupler by allowing the Keg to drain or forcing the contents out with air or C02. The condensate or rinse residuals in a 50 liter or ½ half barrel Keg normally measures between 40 to 80 ml. A limit of 100 ml. should be set as a maximum allowable limit. If the levels are in excess of these amounts, then the machine operation must be checked together with that of the steam quality and relevant steam main condensate traps.

2) The condensate obtained from the Keg can be titrated to ensure that there is no acid and/or alkali carry-over from the wash heads.

NOTE 1: For this check the pH. of the condensate should be a known factor if steam is used for purging.

NOTE 2: This check should be carried out once a day for each machine lane and then reduced to the Quality Control department “comfort level”.

3) Another Keg is used to do a similar check after it has been allowed to complete the sequences through the racker head(s) up to the point of immediately prior to commencing the beer filling sequence. Reject the Keg prior to starting the beer filling sequence and remove the conveyor after discharging from the machine. When checking for the quantity of condensate present in the Keg, it should be less than 15 ml.

NOTE: This check should be carried out once a day for each machine lane and then reduced to the Quality Control department “comfort level”.

MICROBIOLOGICAL CHECKS TO THE KEG

Introduce a liter of sterile liquid, (preferably beer), into a Keg having completed the sequence as described in Procedure 3) above, via a sterilized Keg valve and “funnel” coupler. This allows the Keg to be checked for microbial integrity by removing 250 ml. of the sterile liquid into a sterile flask. Split the sample into two, 100 ml. samples via Millipore type membranes, plate and incubate the membranes on agar suitable for aerobic and anaerobic organisms.

Methods of doing this vary slightly. The main objective, however, is to ensure that consistency in sampling is maintained, i.e. having introduced the sterile liquid into the Keg, each Keg should be rotated a set number of times to ensure all surfaces have been covered equally before it is extracted. A known quantity should always go into the Keg and a known quantity should always be extracted, filtered and plated.

NOTE 1: This procedure should be carried out at least once every two weeks.

NOTE: 2: Funnel couplers can be purchased via IDD to suit your Keg valve type.

AFTER A C.I.P. SEQUENCE

After the C.I.P. sequence, the process mains, bright beer tank and racker connection head(s), can be swabbed and checked for visual cleanliness to ensure that the cleaning operation frequencies are effective and adequate.

NOTE: This should be carried out at least once a week.

BEER STABILITY SAMPLING

Samples are taken from the bright beer tank and Keg at a frequency laid down by the brewery Quality Control department. A suitable stability test is to set aside a Keg of beer from the leg line after filling and “forcing” the contents by leaving the Keg in an environment of 70° F. (21°C). Taste, odor and clarity tests can then be taken after 72 hours and at regular durations thereafter as desired to suit the Quality Control department’s standards.

 

SUMMARY

It is possible to determine the following about the Keg machine function and cleaning procedures from the aforementioned.

1. The wash water and detergent is being cleared from the Keg by the final C02 or steam purge sequence on the final wash head.
2. The final rinse water on the final wash head is removing the detergent residual from the Keg.
3. The C02 purge is removing the condensate trace from the Keg on the racker head prior to filling with beer.
4. The microbial integrity, via steam sterilizing or a sanitizing agent (peracetic acid) of the Keg is being achieved.
5. The separate plant C.I.P. sequence is effective in removing all traces of beer protein and other residuals from the Keg plant connection head(s) and piping system(s).
6. The cleanliness and microbial integrity is being maintained by the separate plant C.I.P. regime.