Hygiene for Craft Brewers A Fleeting Visit

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?



• Chemical

• Physical


Brand Protection



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


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


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.


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


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)


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.


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.


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


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


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.


Carbon Dioxide/Caustic Reactions


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


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


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

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



• Chemical

• Physical


Brand Protection



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

Hygiene for Craft Brewers A Fleeting Visit

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