hygiene for craft brewers a fleeting visit
TRANSCRIPT
Hygiene for Craft Brewers
A Fleeting Visit
Malcolm Swalwell
March 14 2016
CIP- FocusedWhy Clean?
Brewing Hygiene Factors Water Quality
Substrates and Equipment Design
Soil Components
Detergents & Cleaning Programs
Sanitisers
Presentation Scope
Beer-Contamination Risk Management• Microbial
• Chemical
• Physical
Maximising Equipment Efficiencies
Brand Protection
Consumer Safety and Loyalty
Stay in Business and Grow
Hygiene Management…Why Clean and Sanitise at all?
Hygiene Management…Why Clean and Sanitise at all?
Beer-Contamination Risk Management• Microbial
• Chemical
• Physical
Maximising Equipment Efficiencies
Brand Protection
Consumer Safety and Loyalty
Stay in Business and Grow
Brewing Hygiene Factors
Brewing Hygiene Factors
Water Quality – For Cleaning& Sanitising Operations
Hardness
• Scales, Precipitates, Scums
Excess Alkalinity
• Can negatively affect some sanitisers
High Chlorides
• Increased stainless steel corrosion potential in hot neutral- acidic environments and/or low-no flow areas.
Elevated organic content
• Precipitate formation, Sanitiser Deactivation
Brewing Hygiene Factors
Parameter Units Suggested Target Comments
Taste & OdourAesthetically
undetectableDrinking Water Quality especially for final rinsing of process-contact surfaces.
Colour TCU </=15
pH 6-8.5 Low pH (ie acidic) water will cause corrosion issues.
Total Hardness ppm (as CaCO3) </= 100 Excess will contribute to scaling.
Total Alkalinity ppm (as CaCO3) </= 100 Excess bicarbonate can lead to scale formation.
Chloride ppm (Cl -) </= 150 </= 50 ppm recommended for SS304, </= 150 ppm for SS316.
Sulphate ppm (as SO42-) < 250
Excess can contribute to scale formation and may support pitting corrosion in combination with elevated
chlorides.
Iron ppm (Fe) </= 0.1 Excess can cause brown staining issues.
Manganese ppm (Mn) </= 0.05 Excess can cause staining issues.
Silica ppm (as Si4 -) < 10 Excess can lead to scale formation upon drying.
Copper ppm </= 1.0 Excess can cause staining issues.
Hydrogen Sulphide ppbAesthetically
undetectable
Suspended Solids ppm Zero More than 1 ppm causes visible turbidity.
Total Dissolved Solids ppm </= 500
Turbidity Nephelometric </= 5
COD ppm (O2) Zero A measure of organic load.
(Adapted from Wershofen, 2011)
Water Quality Parameters for Cleaning & Sanitising Operations
Brewing Hygiene Factors
Substrates - Material Compatibility Considerations
Stainless Steel (ie 304 grade or better) is great, however care is still required, particularly with regards to acid cleaning in combination with elevated chloride levels and heat.
Mild Steels are stable to alkalis, however they are readily attacked by acids and chlorinated alkalis unless the formulations contain inhibitors.
Soft Metals (eg Aluminium, Brass etc.) require special consideration, and often corrosion inhibited and/or milder detergents are needed.
Polymers and Rubbers require additional considerations. Whilst most offer good detergent compatibility/ resistance, there are exceptions.
Brewing Hygiene Factors
Brewhouse Soil Components
Starch residues (mash & lauter tun)
Denatured proteins
Tannin/protein residues formed during mashing, boiling (hot break) and wortcooling
Hop Residues
Caramelised Sugars
Sugar/amine (Maillard reaction) residues
Scales based mainly on Ca-oxalate, with PO4
3- & SO42- (especially on heat transfer
surfaces) – The basis of Beerstone
Brewing Hygiene Factors
Cellar Vessel Soiling
Tannin/protein residues
Sugar/amine (Maillard) residues
Hop Resins
Yeast deposits
Beerstone – Calcium oxalate(+ carbonate, and a little phosphate & sulphate)
• Typical Wort: 45 – 60 ppm Ca Oxalate
• Typical Beer: 8 – 20 ppm Ca Oxalate
• From the Brewhouse through to Packaging, calcium oxalate can be expected to slowly precipitate out and coat process-contact surfaces. It is caustic insoluble
Carbon Dioxide (CO2)
Brewing Hygiene Factors
Fermenter Soiling
Tannin/protein residues
Sugar/amine (Maillard) residues
Hop Residues
Yeast deposits
Beerstone – Calcium oxalate (+ phosphate & sulphate)
Carbon Dioxide (CO2)
Yeast cells tend to form clumps via a calcium bridging process. Note the brown tannin/protein deposits on the clumps in the yeast ring.
Brewing Hygiene Factors
Protein Structure
HEAT, pH and/or ENZYMES
NATIVE PROTEIN CONFIGURATION DENATURED PROTEIN
The unfolded structure exposes more binding sites (e.g hydrogen bonding groups) and is more likely to combine with other molecules, including phenolics, resins, sugars & other proteins (leading to the formation of larger, insoluble structures).
Soil tenacity is further increased when denatured proteins combine with minerals.
Brewing Hygiene Factors
Brewery Soil Characteristics
Component ExampleWater
Solubility?Heat Effects Detergent Ease of Removal
Organic
Carbohydrates Sugars, Starches Some Caramelisation
Alkali +/-
Oxidant
Easy - Hard
Tannins, polyphenolics Hop Resins No “Fixes” Soil Moderate - Hard
Moderate - HardProteinsHot Break
MaterialSome Denatures
Inorganic
Monovalent SaltsPotassium
ChlorideYes None Hot Water Easy
Beerstone Calcium Oxalate No “Fixes”?Acid or
Chelated Alkali
Moderate
Water ScaleCalcium
CarbonateNo Precipitation Moderate
CIP Basics
CIP Basics
Generalised 5-Step Cleaning & Sanitising Process
Step Function
Pre-rinse Loose, gross soiling removed and/or softened. Reduces demand on the detergent.
WashDetergent application with added energy; to separate the soil from the surface, rendering it into a removable state.
IntermediateRinse
Removes dissolved, suspended, softened & loosened soils, as well as chemical residues.
Sanitise Reduce surface microbial population to a process-ready (not sterile) level.
Post RinseRemoves sanitiser residues (Optional – depending on the sanitiser used, and company/brewer’s/country’s policies)
CIP Basics
Action – CIP Golden Rule
“If the hydraulics aren’t right, nothing else matters!”
CIP Basics
Action – CIP Rule-of-Thumb Pipeline Flow Rate
1.5 m/sec – minimum,
up to 2.0 m/sec
Guarantees turbulent flow which ensures adequate physical scrubbing at internal pipe surface.
CIP Basics
Hygienic Design Flaws in Line Circuits
CIP Basics
Tank CIP Factors
For a continuous vessel CIP process a target of ~30L per minute per metrecircumference of the tank (~0.08 L/s/m2 of tank wall to be cleaned) is targeted.
This provides a suitable thickness of CIP solution to provide sufficient volume and mechanical action from a closed film of cleaning solution running down the tank walls.
CIP Basics
Some Mistakes in Tank CIP
Spray ShadowsPonding
Insufficient Spray Time
CIP Basics
Internal Kegwashing
Clean kegs are critical to the quality of draft beer.
CIP processes similar to that used in cellar tank cleaning are normally used, albeit with temperature.
If not cleaned properly, beerstone/tannin deposits can develop inside kegs. This is especially true for kegs holding unfiltered beer. Beer-spoilers can hide underneath these layers.
Brewing Process Detergents and CIP Programs
BPD and CIP Programs
Materials Typically used in Alkaline Detergents
Alkali Sources• Caustic Soda/Potash
• Alkaline Silicates
• Trisodium Phosphate
• Carbonates
Sequestrants• Condensed Phosphates
• Phosphonates
• Polymers (eg Polyacrylates)
• Gluconate/Glucoheptonate
Chelants• Aminocarboxylates
(eg. EDTA)
Detergency Properties:• Organic Dissolving Power
• Protein Hydrolysis
• Emulsification
• Fat Saponification
• Water softening
• Soil dispersion
• Antiredeposition
• Emulsification
• Scale inhibition
• Water softening
• Scale stripping (eg Beerstone)
• Mineral deposit control
BPD and CIP Programs
Normally used in conjunction with alkalies to remove particularly stubborn (eg burnt-on or polymerised) soil residuals on either a maintenance or remedial basis. Active oxygen donors possess an additional physical scrubbing action via oxygen bubble release.
Alkali-Boosting OxidantsChlorine Donors and Active Oxygen DonorsOxidative cleavage of protein peptide bonds and sulphide bridges
-[- H N – C H R1 – H C – N H – C H R2 – C O -]-
=O
Peptide Bond
S S
Sulphide Bridge
BPD and CIP Programs
Caustic/Carbon Dioxide Reactions
1) 2NaOH + CO2 Na2CO3 + H2OSodium Carbon Sodium WaterHydroxide Dioxide Carbonate(Caustic)
2) Na2CO3 + CO2 + H2O 2NaHCO3
SodiumBicarbonate
These reactions remove CO2 gas from inside cellar vessels (even after a good blowdown), potentially leading to vacuum formation and possible tank implosion, unless the vessel is vented to atmosphere and/or other allowances are made during caustic CIP.
BPD and CIP Programs
Carbon Dioxide/Caustic Reactions
BPD and CIP Programs
Mineral Acids Phosphoric, Nitric, Sulphuric,
Sulphamic & combinations
Short Chain Organic Acids eg Citric, Glycolic, Formic, Acetic,
Lactic, MSA,
Solvents
Corrosion Inhibitors
Detergency Properties Beerstone removal & mineral deposit control Some protein hydrolysis
Can enhance stone removal speed of phosphoric, and improve overall sulphuric/nitric detergency.
Some function as Acidulants (ie Provide biocidal/static effects)
Assists removal of organics
Substrate protection
Materials Typically used in Acid Detergents
BPD and CIP Programs
Surfactants - Typically used in most Detergents
Surface wetting and crevice infiltration
Soil penetration, emulsification, dispersion and antiredeposition
Determines foam characteristics of the detergent use-solution.
Head(Water-loving)
Tail(Oil-loving)
Surfactants make water wetter!
Water 72 mNm
Milk 52 - 55 mNm
Beer 43 - 47 mNm
Target <40 mNm
Unwetted Caustic >72 mNm
Adapted from Schoorens, 1982
BPD and CIP Programs
Example Brewery CIP Programs3-Step - Hot
1. Hot Rinse (10-15 min)
2. Wash with hot caustic detergent (2-3% w/v NaOH/55-85°C/20-45 min)
3. Hot Rinse (10-15 min)
AREAS OF USE
Brewhouse Vessel and Wort Lines
Wort Cooler
Internal Filler (& Filler Buffer Tanks) Internal Kegwash
A well chelated, caustic detergentsuggested for small-medium craftbrewing CIP operations unless periodicacid use is planned.
5-Step - Ambient
1. Blowdown or Vent (CO2 removal)
2. Rinse (10-15 min)*
3. Wash - Caustic (2% w/v NaOH) or Acid (2% v/v) for 20 min
4. Rinse (10-15 min)
5. Sanitise (1 - 2% v/v Acid-Fatty Acid/30 min or 150 ppm PAA/15 min)
6. Rinse (10 min)
(* Step 2 often omitted for FV CIP; and a sacrificial, 0.5-0/9% w/v NaOH preflush used instead.)
AREAS OF USE
Filters
Fermenters (FV’s)
Lagering Vessels & BBTS
Times are only suggested. They will vary widely depending on the vessel being processed as well as the CIP set capabilities, especially if burst routines are available.
Craft Brewery CIP Sanitisers
CIP Sanitisers
Why Sanitise?
Step Function
Pre-rinse Loose, gross soiling removed and/or softened. Reduces demand on the detergent.
WashDetergent application with added energy; to separate the soil from the surface, rendering it into a removable state.
IntermediateRinse
Removes dissolved, suspended, softened & loosened soils, as well as chemical residues.
Sanitise Reduce surface microbial population to a process-ready (not sterile) level.
Post RinseRemoves sanitiser residues (Optional – depending on the sanitiser used, and company/brewer’s/country’s policies)
CIP Sanitisers
Why Sanitise?
Step Function
Pre-rinse Loose, gross soiling removed and/or softened. Reduces demand on the detergent.
WashDetergent application with added energy; to separate the soil from the surface, rendering it into a removable state.
IntermediateRinse
Removes dissolved, suspended, softened & loosened soils, as well as chemical residues.
Sanitise Reduce surface microbial population to a process-ready (not sterile) level.
Post RinseRemoves sanitiser residues (Optional – depending on the sanitiser used, and company/brewer’s/country’s policies)
CIP Sanitisers
Hot Water Sanitation
Rinse
Rinse
DetergentClean
Sanitize
80-85 C,15-20 Min.
(Try googling the A0 concept)
Pitfalls: Water scale formation/Soil bake-on and
associated insulation effects. Equipment wear and tear. High energy inputPositives: No chemical residues or storage issues Conduction effects
CIP Sanitisers
Advantages Broad spectrum
Excellent low T performance
Not considered corrosive to SS and Al (excessive chloride levels aside)
Environmentally sound
No-rinse possible
No foam
Disadvantages Moderate cost in-use
Excessive residuals can taint
Operator safety
Yellow metal & mild steel corrosion
Aggressive to some rubbers
Soil deactivation
Peracetic Acid
Mixed Peracids have improved fungicidal activity over PAA.
CIP Sanitisers
Acid-Fatty Acid
Advantages Broad Spectrum
Good beer compatibility profile
Low SS Corrosion
Descaling effects
Good Reclaimability
Good Water Hardness Tolerance
Low foam –Suits CIP
Non-persistent in biological effluent treatment systems (due to activity loss as pH lifts)
Disadvantages More expensive in terms of cost
per litre, but full reclaimabilitymakes them cost competitive in practice.
Longer contact times required compared to peracids.
CIP Sanitisers
Acid Anionics
Acid-fatty acid detergent/sanitisers are much more prevalent these days than acid-anionics in the larger breweries for cellar equipment and line CIP.
Advantages Descaling ability Rapid activity against most organisms Good water hardness tolerance Low corrosion risk on most processing
equipment Non-persistent in biological effluent
treatment systems (due to activity loss as pH lifts)
Disadvantages May foam too much for CIP Often have a high P content Beer haze risk Low T performance?
CIP Sanitisers
Suggested Sanitisers for Specific Application Areas in Craft BrewingSanitiser
Hot Water
If reclaiming: Acid-Fatty Acid. If not: Peracetic Acid/Mixed Peracids
Acid-Anionic, QAC, or Peracetic Acid (PAA)
Alcohol, Acid-Anionic, PAA
Hot water, PAA
Chlorine or Chlorine Dioxide
Area of Use Brewhouse Vessel, Wort Line & Wort
Complexing Equipment CIP,
Cellar Vessels And Beer Transfer Equipment.
Flexible Hoses, Key Pieces, Removable Fittings, Soak Tanks, Filler Externals, Environmental
Sample Ports
Internal Filler CIP
Rinse Water Treatment
CIP Sanitisers
Hygiene Program Monitoring Periodic Visual InspectionsSeeing is believing, and don’t forget the nose!
Black lights can help.
Look for scale or “burn-on” on heat exchange surfaces.
Check for yeast ring and dome residues in fermenters.
Look for brown “pond” or “tide” marks in cellar vessel cones.
Check for blind spots or CIP shadow areas inside tanks.
Look around manhole covers and inspection door seals.
Check volume gauge lines.
Watch your flexible hoses.
Check COP tanks regularly
Hygiene Management…Why Clean and Sanitise at all?
Beer-Contamination Risk Management• Microbial
• Chemical
• Physical
Maximising Equipment Efficiencies
Brand Protection
Consumer Safety and Loyalty
Stay in Business and Grow
Thank You
Bibliography
Knettel, K. “One Page regarding Tannin Removal” 2012 Ecolab
Rouillard, C. “The Chemistry of Cleaning” 1994
Schoorens, J. “Acid Cleaning & Related Disinfection in Breweries” 1982 The Brewer, January, pp 13-20.
Wershofen, T “One Page Regarding Water Quality for Cleaning Solutions” 2011 Ecolab