May 20, 2017

Cleaning and Sanitation

Purpose of Cleaning and Sanitation

  • cleaning: remove nutrition and protection of microorganism
  • sanitization: using a biocide, can't kill spore
  • sterilization: complete removal of microorganism, hard for general brewpub
  • physical cleaning
  • chemical cleaning
  • microorganism cleaning: every brewing equipment after boiling

Controlling step

  1. cleaning: remove dirt and soil from a surface of tools 
  2. sanitization: disinfection for prohibiting the growth of microorganism, using chemical or heat(minimum 15min, above 120'c with steam) 
  3. sterilization: complete remove living cells, prevent infection of wort

Detergent

  • Alkaline detergent for organic soil(sugar, protein in a kettle): at high temperature
  • Acidic detergent for inorganic matter(scale caused by hard water, beer stone in a fermentor or keg): at low temperature(for rinse water as well)

Ingredients of detergent

  • water
  • dissolving agent
  • surfactant: lower surface tension
  • chelating agent: reactive with metal ion first, help surfactant work well 
  • rinse agent
  • oxidizing agent: remove bad protein
  • disinfectants for terminal rinsing, for soaking bath

alkaline detergent

  • attack organic matter. mainly Caustic soda(Sodium hydroxide). 
  • better in higher pH and above 65'c, 2-5%. reactive with CO2. 
  • Chlorinated caustic or Chlorinated alkali for stronger one(*maximum amount of Chlorine must below 200ppm, pH above 11)
  • need sequestrant for preventing scaling: stoichiometric sequestrant, threshold sequestrant

acid detergent

  • attack inorganic matter
  • effective in pH below 2.5. not reactive with CO2. 
  • not for cleaning a fermentor. ineffective compared to alkaline detergent(or pre-rinse with alkaline detergent before use) 
  • mainly use for keg cleaning.
  • cautious safety!

How to choose right detergent

  • legally ok?
  • organic(brewhouse) or inorganic(bottling line)?
  • highly corrosive?
  • residue and its impact
  • time, temperature, concentration, by hand(or machine)
  • is it safe for staff?
  • no impact on finish products?
  • safe for the environment?
  • easy to monitor?

No rinse sanitizer

  • Hydrogen Peroxide: no impact on beer, safe but strong acid and easy to fire
  • Peroxyacetic acids/Percetic acids(aka 스타산): effective in wide range of temperature, no harm for stainless steel

Other sanitizer/disinfectant(must rinse)

  • Sodium hypochlorite: activated chlorine under pH 5, relatively stable. 50-300mg/L and use for terminal sterilant 
  • Chlorine dioxide: remove microorganism and biofilm, no harm for aroma, sanitize water with 0.2ppm(no need to rinse again), 5ppm for sanitizer(must rinse)
  • Hypochlorite(bleach): corrode stainless steel, OK with low temp and hard water, less good for organic matter but can produce chlorophenol and chloramine -> replaced with Chlorine dioxide
  • Formaldehyde: not safe(not used in US and Europe), very effective and cheap 
  • Ammonium compounds: not corrosive, make bubbles, bad for foam stability 
  • Iodophors: Iodine+active agent. 10mg/L. highly noticeable red color, good for soak bath, bad in low temp and organic matter
  • Ultra violet light: use for sanitizing water, effective only for clear water
  • Peracetic acid: separate into acetic acid+hydrogen peroxide. 75-300mg/L at low temperature. need to ventilate, so replaced with chlorine dioxide. 

Pasteurization

  • tunnel pasteurizer: 20min in 65'c
  • flash pasteruizer: 15c in 73'c
  • hot water: longer than 20min in 85'c
  • hot steam: longer than 15min in 120'c

CIP(Cleaning in place) - Cleaning cycle

  1. perfectly empty the equipment 
  2. pre-rinse
  3. put detergent, rotating CIP circuit for 20~30mins
  4. detergent out(or re-collected)
  5. rinse with acidic liquid where alkaline detergent was used
  6. final rinse with terminal sterilant
  • brewhouse: pre-rinse 10~15mins > detergent(caustic) recycling 20~30mins > post rinse 5~10 mins
  • fermentation vessel, maturation vessel, yeast vessel: pre rinse 10~15 > hot caustic recycling 20~30 > post rinse 5 > sterilant recycling 10~20 > post rinse 5~10
  • or : hot caustic recycling and drain 30 > post rinse > *(cold acidic detergent recycling 15~20 > post rinse 5) > sterilant recycling > post rinse. * is 1~2 per week
  • BBT(bright beer tank): pre rinse 5~10 > cold acidic detergent recycling > post rinse 5 > sterilant recycling 10~20 > post rinse 5~10

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