Brewing  Science  

Cleaning  

Brewery  Cleaning  and  Sanita1on  

•  Cleaning  and  sanita1on  are  integral  parts  of  successful  brewing  

•  Cleaning:  removal  of  organic  and  inorganic  residues  and  microorganisms  

•  Sanita1on:  reduce  the  popula1on  of  viable  microorganisms  and  prevent  microbial  growth  

Cleaning  

•  Cleaning  agents  broadly  fall  into  alkaline  or  acidic  detergents;  o>en  with  added  surfactants,  chela1ng  agents,  and  emulsifiers  

•  Must  (1)  wet  surfaces,  (2)  penetrate  residue  deposits,  (3)  hold  par1cles  in  suspension,  and  (4)  keep  inorganic  ions  in  solu1on  

Alkaline  Detergents  

•  Effec1vely  remove  organics:  oils,  fats,  proteins,  starches  

•  Hydrolyze  pep1de  bonds,  breaking  down  proteins  

•  Ineffec1ve  against  inorganics  such  as  calcium  oxalate  and  can  leave  “beerstone”  

•  PBW  is  a  good  example  

Alkaline  Detergents  •  Sodium  Hydroxide:  “Its  effec1veness  in  dissolving  

proteinaceous  soils  and  faTy  oils  by  saphonifica1on  is  virtually  unsurpassed.  This  makes  it  a  natural  choice  for  cleaning  sludge  off  the  boToms  of  boilers  and  for  cleaning  beer  kegs.  Sodium  hydroxide  is  an  acutely  excellent  emulsifier  too.  It  is  unrivaled  in  its  ability  to  dissolve  protein  and  organic  maTer  if  used  in  conjunc1on  with  chlorine,  surfactants,  and  chela1ng  agents.”  

•  Sodium  Hydroxide  /  Hypochlorite  Solu1ons:  “Caus1c/hypochlorite  mixtures  are  par1cularly  effec1ve  in  removing  tannin  deposits,  but  are  used  for  a  great  variety  of  cleaning  tasks.  These  mixtures  can  be  used  in  CIP  systems  for  occasional  purge  treatments  or  to  brighten  stainless  steel.”  

Acid  Detergents  

•  O>en  used  in  two  step  process  with  alkaine  detergents  

•  Less  effec1ve  against  soil,  tannins,  oils,  resins,  and  glucans  

•  Remove  beerstone  /  calcium  oxalate,  waterscale  (Ca  and  Mg  carbonates),  and  aluminum  oxides  

•  More  effec1ve  against  bacteria  

Acid  Detergents  

•  Phosphoric  Acid:  widely  used  to  remove  deposits,  enhanced  by  acid-­‐stable  surfactants.    Generally  less  effec1ve  below  16  cen1grade.  

•  Nitric  Acid:  removes  deposits  and  has  biocidial  proper1es,  par1cularly  in  mixture  with  phosphoric  acid.    Also  breaks  down  protein.    Acid  Cleaner  #5  is  an  example.  

Addi1ves  

•  Surfactants  /  Webng  Agents  

•  Chela1ng  Agents  (EDTA,  sodium  gluconate,  sodium  tripolyphosphate)  

•  Emulsifiers  (orthophosphates  and  complex  phosphates)  

Sanita1on  

•  Sani1zing  or  disinfec1ng  agents  used  to  reduce  the  level  of  microorganisms  

•  Simple  physical  methods  include  hot  water  or  hot  steam  

•  Chemical  sani1zers  range  in  effec1veness,  temperature,  and  contact  1me  requirements  

Alkaline  Sani1zers  

•  Chlorine:  Broad  spectrum  germicides  that  disrupt  membranes,  inhibit  glucose  metabolism,  and  oxidize  protein.    Ac1ve  at  low  temperatures,  inexpensive,  leaves  low  residue  

•  Quaternary  Ammonium:  stable  and  non-­‐corrosive,  rapid  bactericidal  ac1on  at  low  concentra1ons.    Efficient  against  gram-­‐posi1ve  bacteria,  yeast,  and  mold.    Ineffec1ve  against  gram-­‐nega1ve  bacteria.    (Quantum)  

Acidic  Sani1zers  •  Hydrogen  Peroxide:  broad  spectrum,  beTer  against  gram-­‐nega1ve.  

•  Peroxyace1c  Acid:  germicidal,  no  vapor  issues  or  foam.    Requires  rela1vely  high  concentra1ons.  

•  Anionic  Acids    (Star  San)  •  Iodophores:  wide  biocidal  spectrum,  equally  effec1ve  to  all  microorganisms,  but  may  have  staining  problems.  (IO  Star)  

Methods  in  Brewery  Cleaning  •  Manual:  “Many  cra>  brewers  do  not  have  the  luxury  of  cleaning-­‐in-­‐place  systems  and  have  to  manually  clean  and  sani1ze  their  equipment.  They  o>en  have  to  use  so>-­‐bristled  brushes,  non-­‐abrasive  pads,  cloths,  and  handheld  spray  hoses  for  cleaning.  When  cleaning  manually,  great  care  must  be  taken  to  assure  that  brushes  and  equipment  are  cleaned  to  avoid  cross-­‐contamina1on.”  

• Clean  in  Place  

In  Depth  CIP  

The  following  slides  are  from:    

Principles  and  Prac.ce  of  Cleaning  in  Place  Graham  Broadhurst  Great  Lakes  Water  Conserva1on  Conference,  October  2010    

CIP  /  SIP  -­‐  Defini1on  

•  CIP  =  Cleaning  in  Place  – To  clean  the  product  contact  surfaces  of  vessels,  equipment  and  pipework  in  place.  i.e.  without  dismantling.  

•  SIP  =  Sterilise  in  Place  – To  ensure  product  contact  surfaces  are  sufficiently  sterile  to  minimise  product  infec1on.  

How  CIP  Works  

•  Mechanical  –  Removes  ‘loose’  soil  by  Impact  /  Turbulence  

•  Chemical  –  Breaks  up  and  removes  remaining  soil  by  Chemical  ac1on  

•  Sterilant/Sani1ser  –  ‘Kills’  remaining  micro-­‐organisms  (to  an  acceptable  level)  

Factors  affec1ng  CIP  

•  Mechanical      

•  Chemical    

•  Temperature    

•  Time  

CIP  Opera1on  

•  PRE-­‐RINSE    -­‐  Mechanical  Removal  of  Soil  

•  DETERGENT    -­‐  Cleaning  of  Remaining  Soil    -­‐  Caus1c,  Acid  or  Both  

•  FINAL  RINSE    -­‐  Wash  Residual  Detergent/Soil  

•  STERILANT/SANITISER    -­‐  Cold  or  Hot  

Typical  CIP  Times      

 Vessel CIP  

 Mains CIP  

 

Pre-Rinse    

10 to 20 mins    

5 to 10 mins    

Caustic Detergent    

30 to 45 mins    

20 to 30 mins    

Rinse    

10 to 15 mins    

5 to 10 mins    

Acid Detergent    

20 to 30 mins    

15 to 20 mins    

Rinse    

15 to 20 mins    

10 to 15 mins    

Sterilant    

10 to 15 mins    

5 to 10 mins    

Typical  CIP  Temperature  

•  Brewhouse  Vessels  Hot  85°C  •  Brewhouse  Mains    Hot  85°C  •  Process  Vessels    Cold  <  40°C  •  Process  Mains    Hot  75°C  •  Yeast  Vessels    Hot  75°C  •  Yeast  Mains      Hot  75°C  

CIP  Detergent  -­‐  Requirements  

•  Effec1ve  on  target  soil  •  Non  foaming  or  include  an1-­‐foam  •  Free  rinsing  /  Non  tain1ng  •  Non  corrosive  –  Vessels/pipes,  joints  •  Controllable  -­‐  Conduc1vity  •  Environmental  

Caus1c  Detergents  •  Advantages  

–  Excellent  detergency  proper1es  when  “formulated”  

–  Disinfec1on  proper1es,  especially  when  used  hot.  

–  Effec1ve  at  removal  of  protein  soil.  

–  Auto  strength  control  by  conduc1vity  meter  

–  More  effec1ve  than  acid  in  high  soil  environment  

–  Cost  effec1ve  

•  Disadvantages  –  Degraded  by  CO2  forming  

carbonate.    –  Ineffec1ve  at  removing  inorganic  

scale.  –  Poor  rinsability.  –  Not  compa1ble  with  Aluminium  –  Ac1vity  affected  by  water  

hardness.  

Acid  Detergents  •  Advantages  

–  Effec1ve  at  removal  of  inorganic  scale  

–  Not  degraded  by  CO2  –  Not  affected  by  water  

hardness  –  Lends  itself  to  automa1c  

control  by  conduc1vity  meter.  

–  Effec1ve  in  low  soil  environment  

–  Readily  rinsed  

•  Disadvantages  –  Less  effec1ve  at  removing  

organic  soil.    New  formula1ons  more  effec1ve.  

–  Limited  biocidal  proper1es  -­‐  New  products  being  formulated  which  do  have  biocidal  ac1vity  

–  Limited  effec1veness  in  high  soil  environments  

–  High  corrosion  risk  -­‐  Nitric  Acid  –  Environment  –  Phosphate/

Nitrate  discharge  

Detergent  Addi1ves  

•  Sequestrants  (Chela1ng  Agents)  – Materials  which  can  complex  metal  ions  in  solu1on,  preven1ng  precipita1on  of  the  insoluble  salts  of  the  metal  ions  (e.g.  scale).    

–  e.g.  EDTA,  NTA,  Gluconates  and  Phosphonates.  •  Surfactants  (Webng  Agents)  

–  Reduce  surface  tension  –  allowing  detergent  to  reach  metal  surface.  

Sterilant  /  Sani1ser  Requirements  

•  Effec1ve  against  target  organisms  •  Fast  Ac1ng  •  Low  Hazard  •  Low  Corrosion  •  Non  Tain1ng  •  No  Effect  On  Head  Reten1on  •  Acceptable  Foam  Characteris1cs  

Sterilants  /  Sani1sers  

•  Chlorine  Dioxide  •  Hypochlorite  •  Iodophor  •  Acid  Anionic  •  Quaternary  Ammonium    •  Hydrogen  Peroxide    •  PAA  (Peroxyace1c  Acid)  –  200-­‐300  ppm  

CIP  Systems  

•  Single  Use    – Water/Effluent/Energy  costs  

•  Recovery  – Detergent  Recovery    – Rinse/Interface  Recovery    

•  Tank  Alloca1on  •  Number  of  Circuits  

Single  Use  CIP  Systems  

CIP Buffer Tank

Water Conductivity Flow

CIP Return

CIP Supply

Conductivity Flow CIP Supply Pump

Temperature

CIP Heater

Steam

Recovery  CIP  Systems  1  x  Supply  –  3  Tank  System  

Final Rinse Tank

Water Conductivity Flow CIP Return

CIP Supply Flow CIP

Supply / Recirc Pump

Temperature CIP

Heater

Steam

Pre-Rinse Tank

Caustic Tank

CIP Return / Recirc

CIP Supply / Recirc

LSH

LSL

LSH

LSL

LSH

LSL

Temp

Recovery  CIP  Systems  2  x  Supply  –  4  Tank  System  –  Separate  Recirc  

CIP Supply A

LSH

Final Rinse Tank

Water

Cond Flow

CIP Return A

Flow CIP Supply A Pump

Pre-Rinse Tank

Caustic Tank

LSH

LT

LSH

LT

LSH

LT

Temp

Caustic Recirc Pump

Temp

Acid Tank

LT Acid Recirc Pump

Cond Cond

Cond Flow

CIP Return B

CIP Supply B

Flow CIP Supply B Pump

Recovery  CIP  System  

Single  Use  vs  Recovery  •  Single  Use  CIP  

–  Low  Capital  Cost  –  Small  Space  Req.  –  Low  Contamina1on  Risk    –  Total  Loss  

•  High  Water  Use  •  High  Energy  Use  •  High  Effluent  Vols.  

–  Longer  Time/Delay  –  Use  for  Yeast  

•  Recovery  CIP  –  High  Capital  Cost  –  Large  Space  Req.  –  Higher  Contamina1on  Risk  –  Low  Loss  

•  Low  Water  Use  •  Low  Energy  Use  •  Low  Effluent  Vols.  

–  Shorter  Time/Delay  –  Use  for  Brewhouse  &  

Fermen1ng  

CIP  Systems  CIP  Tank  Sizing  

•  Pre-­‐Rinse  –   CIP  Flow  x  Time  

•  Detergent  – Vol  of  CIP  in  Process  Mains  &  Tank    +  Losses  

•  Final  Rinse  – Flow  x  Time  –  Water  Fill  

CIP  Systems  Prac1cal  Points  

•  CIP  Supply  Pump  •  Recircula1on  

– Shared/Common  with  CIP  Supply,  or  – Dedicated  to  Tank  

•  CIP  Supply  Strainer  •  CIP  Return  Strainer  •  CIP  Tank  Connec1ons  

Types  of  CIP  

•  VESSEL  CIP    -­‐  Sprayhead  Selec1on    -­‐  Scavenge  Control  

•  MAINS  CIP    -­‐  Adequate  Velocity    -­‐  Total  Route  Coverage  

•  BATCH/COMBINED  CIP    -­‐  Complex  Control      -­‐  Time  Consuming  

Vessel  CIP  

•  Flow  of  CIP  fluid  from  CIP  supply  to  vessel  sprayhead  

•  Internal  surfaces  cleaned  by  spray  impact  /  deluge  

•  Return  from  vessel  by  CIP  scavenge  (return)  pump  

CIP Return

CIP Supply

CIP Scavenge Pump

Process Vessel

CIP Gas pipe

Isolate from Process

Vessel  CIP  -­‐  Sprayheads  

•  Sta1c  Sprayballs  – High  Flow  /  Low  Pressure  

•  Rota1ng  Sprayheads  – Low  Flow  /  Medium  Pressure  

•  Cleaning  Machines  – Low  Flow  /  High  Pressure  – High  Impact  

Vessel  CIP  –  Sprayballs  •  Advantages  

–  No  moving  parts  –  Low  Capital  Cost  –  Low  pressure  CIP  supply  –  Verifica1on  by  Flow  

•  Disadvantages  –  High  Water  &  Energy  Use  –  High  Effluent  volumes  –  Limited  throw  –  Small  vessels  –  Spray  Atomises  if  Pressure  High  –  No  impact  -­‐  long  CIP  1me  and/or  high  

detergent  strength  –  Higher  absorp1on  of  CO2  by  caus1c  

Vessel  CIP  –  Rotary  Sprayheads  •  Advantages  

–  Not  too  Expensive  –  Some  Mechanical  Soil  Removal  –  Lower  Flow  –  Reasonable  Water/Energy  Usage  –  Reasonable  Effluent  

•  Disadvantages  –  Moving  parts  –  Limited  throw  –  Small  vessels  –  Possible  blockage  

•  Rota1on  verifica1on  •  Supply  strainer  

Vessel  CIP  –  Cleaning  Machines  

•  Advantages  –  High  impact,  aggressive  

cleaning  –  Good  for  heavy  duty  

cleaning  –  Low  water/energy  use  –  Low  effluent  –  Effec1ve  in  large  vessels  –  Lower  absorp1on  of  CO2  by  

caus1c  –  Lower  Flow  means  smaller  

Pipework  

Vessel  CIP  –  Cleaning  Machines  

•  Disadvantages  –  Expensive  – Moving  parts  –  High  pressure  CIP  supply  pump  

–  Possible  blockage  •  Rota1on  verifica1on  •  Supply  strainer  

Mains  CIP  

•  Flow  of  CIP  fluid  from  CIP  supply,  through  process  pipework  and  back  to  CIP  set  

•  The  en1re  process  route  must  see  turbulent  CIP  Flow  

•  No/Minimal  Tees/dead  legs  

•  Isolate  from  other  process  lines   CIP Return

CIP Supply

Isolate from Process

Isolate from other Process routes

Process Route being CIP’d

Mains  CIP  Turbulent  &  Laminar  Flow  

Mains  CIP  Turbulent  &  Laminar  Flow  

•  Turbulent  Flow  –  Flat  velocity  

profile  –  Thin  Boundary  

layer  –  Effec1ve  CIP  

•  Laminar  Flow  –  Streamline  flow  –  Velocity  profile,  

faster  at  centre  –  Ineffec1ve  CIP  

Thin Boundary Layer at pipe wall

Mains  CIP  

•  Turbulent  Flow  –  – Re  >  3000  

•  Minimise  Boundary  layer  –    – Laminar  layer  on  internal  pipe  wall    

•  Minimum  CIP  velocity  (in  process  pipe)  ≥  1.5  m/s.  

•  Excessive  velocity    – High  Pressure  drop  /  Energy  input  

Mains  CIP  –  CIP  Flow  Process Pipe dia

(mm)

Minimum CIP Flow

(m3/h)

CIP Supply / Return dia

(mm)25 2.1 2538 5.2 3850 10 5065 16 6575 24 65100 42 75125 70 100150 100 125200 170 150250 280 200300 400 200350 520 250400 700 250

Min CIP Velocity 1.5 m/s minimumBased on o/d tube to 100 mm and metric I/d above 100 mm.

Process  Pipework  Design  for  CIP  

•  Ensure  Total  Route  coverage  –  Avoid  Split  routes    

–  Avoid  Dead  ends    

–  Avoid  Tees    

– Most  Cri1cal  on  Yeast  &  nearer  packaging  

Process  Pipework  Design  for  CIP  

•  Isolate  CIP  from  Process    – Mixproof  Valves      

–  Flowplates  

CIP Return

Process Line – Not being CIP’d

Process Line –being CIP’d

FLOWPLATE

Physical Break between routes

Batch/Combined  CIP  

•  Combines  CIP  of    – Vessel/s  and  – Pipework  in  one  clean  

•  Why  ?  – Pipework  too  large  for  ‘mains’  CIP  e.g.  Brewhouse  200  to  600  mm.  

– Pipework  linked  to  Vessel    e.g.  Recircula1on  Loop  or  EWH.  

Batch/Combined  CIP  

•  Supply  of  a  batch  volume  of  CIP  to  process  vessel  

•  Internal  recircula1on  of  CIP  within/through  process  vessel  

•  Transfer  of  CIP  to  next  vessel  •  Pumped  return  of  CIP  batch  volume  to  CIP  set.    

CIP  Monitoring  &  Control  On-­‐Line  

•  Detergent  Temperature  •  Detergent  Strength  -­‐  Conduc1vity  •  Return  Conduc1vity  

–  Detergent  Start  Interface  –  Detergent  End  Interface  –  Rinse  Conduc1vity  

•  Return  Flow  •  Recirc/Return  Time  •  Supply  Pressure  

CIP  Monitoring  &  Control  Off-­‐Line  

•  Visual  Inspec1on  •  Final  Rinse  return  sampling  

–  pH  – Micro  –  ATP  

•  Vessel/Pipework  swabs  –  pH  – Micro  –  ATP