Unit 7 Flashcards
3 definitions of quality
1 - as fit for purpose
2- as customer satisfaction
3 - as conforming to specification
Overall definition of quality
Conformance to specification which incorporate customer wants and needs, as well as legislation. Produces consistent product and customer satisfaction
2 aspects of quality management
Quality control & Quality assurance
Define quality control
Inspect/sample product against specification and take corrective action if it does not meet specification. Usually performed before progression to the next ‘stage’ of production.
Define quality assurance
Develop and implement systems which prevent the product from becoming inadequate. Real time measurements of key process control conditions.
Definition of Total Quality Management
Management approach of an organisation centred on quality, based on participation of all members and long term success and customer satisfaction
12 principles of Total Quality Management
- Quality can and must be managed.
- Everyone is a supplier with a customer.
- Processes, not people, are the problem.
- Every employee is responsible for quality.
- Problems must be prevented, not just fixed.
- Quality must be measured.
- Quality improvements must be continuous.
- The quality standard is defect free.
- Goals are based on requirements, not negotiated.
- Life-cycle costs, not front end costs.
- Management must be involved and lead.
- Plan and organise for quality improvement.
Quality control examples
Testing spirit ABV once produced.
Sensory assessment of spirit once produced
Quality assurance examples
Monitoring of distillation temperature and pressure.
Monitoring of spirit ABV during distillation.
Energy and wash feed to stills.
Differences between quality control and assurance
Assurance is proactive, control is reactive.
Assurance is on-going throughout production, control is one-off, pass/fail.
Control is about measurement and inspection of products (product orientated), while assurance is is about demonstrating confidence in processes and products, as well as their improvement (process orientated.)
Assurance - everyone responsible, QC team responsible for control.
Assurance prevents problems, while control identifies and removes problems when they occur.
Theory behind quality assurance
Changes can be made to chosen process conditions to ensure the product is within specification.
2 main principles of quality assurance
Fit for purpose
Right first time
6 steps of the quality assurance process
1 - define the requirements and responsibilities related to all areas of production
2 - define the product requirements.
3- Define all materials, packaging, technologies, and storage techniques required, as well as the number and qualification of people.
4- analyses sources of faults and factors affecting quality
5 - Define the quality assurance actions, information, education, training, motivation, investigation parameters, methods of analysis, and sampling documents.
6 - Define responsibilities for certain quality reassurance actions.
Simplified steps of quality assurance process
1- Defining what needs to be managed.
2 - Quantifying it
3 - Assembling the capability to measure and manage it.
4 - Allocating responsibility for measurement and managing.
What is PDCA?
Cycle of quality assurance
Plan - Do - Check - Act
AKA - the Demming Wheel
Nine elements of a formal quality management system
1- Quality objectives
2- Quality manual (policies, structures, procedures, responsibilities)
3- Organisational structure and responsibilities.
4- Data management
5- Internal process management (audits, etc)
6- Product quality leading to customer satisfaction.
7- Continuous improvement (inc corrective and preventative actions)
8- Analysis of key quality attributes
9- Document control
QMS document structure
Policy - defines what will be done
Procedures - By who, and to what standard
SOPs - How
Records - Proof/Evidence
ACT components of a Deming Wheel focussed QMS
Management Responsibility Process
-Manage commitment and customer focus
-Quality policy and objectives
-QMS
-Quality plans
PLAN components of a Deming Wheel focussed QMS
Resource Management Process
-HR
-Training
-Competences
-Communications
-People infrastructure
-Work environment
DO components of a Deming Wheel focussed QMS
Product Realisation Process
-Product design
-Supplier management
-Operations planning and control.
-Manufacturing processes
CHECK components of a Deming Wheel focussed QMS
Measurement, Analysis, and Improvement Process
- Customer satisfaction
- Monitoring processes
- Internal audits
- Management reviews
- Improvement processes
- Control of non-conforming material.
What does ISO stand for?
International Organisation for Standardisation
Commercial benefits of a formal QMS
- Credibility and business image.
- market access and competitiveness.
- Efficiency (reduction in product quality failure)
- Easier compliance with regulations.
- Simpler integration of other standards (H&S, food hygiene, integrity, environmental)
- Improvement of organisation wide quality awareness.
- Reduced workload in QM with leadership changes (consistency)
- Better long-term supplier/customer relationships.
- Continuous quality improvement.
Essential components of an ISO9000 QMS
ISO 9001:2015 - requirements of the QMS.
ISO 9000:2015 - Setting out basic concept and language.
ISO 9004:2009 - means to ensure you have efficient and effective QMS
ISO 19011:2011 - Providing guidance on internal and external audits of QMSs.
7 quality management principles of ISO9000
1 - Customer focus
2 - Leadership
3 - Engagement of people
4 - Process approach
5 - Improvement
6 - Evidence-based decision making
7 - Relationship management
10 requirements of a QMS outlined in ISO9001:2015 (based on the PDCA cycle)
1 - Scope
2 - Normative references
3 - Terms and definitions
4 - Context of the organisation
5 - Leadership
6 - Planning
7 - Support
8 - Operation
9 - Performance evaluation
10 - Improvement
How often are ISO standards updated?
Every 5 years
Quality Assurance Tools (apart from ISO9000)
Cost-benefit analysis
5S (sort, set in order, shine, standardise, sustain)
Control charts
Statistical sampling
Define a safety hazard in a food/drink business
- foreign body that might choke/harm
- chemical contaminant causing long/short term sickness
- Any adulteration by uncontrolled access to the product by external sources
2 main components of GMPs
Written programs & implementation (with auditable records)
GMP - Environmental control elements
-location
- building design & construction
-water supply
- equipment & interior
GMP - Personnel elements
-personal hygiene
- hand washing
- workwear
- injuries/wounds
- evidence of illness
- access
- chemical use
GMP - pest control elements
- procedures for interior and exterior of the building
GMP - Sanitation elements
-cleaning and sanitising procedures
- preoperational assessment
GMP - equipment maintenance elements
-preventative maintenance
- calibrations
GMP - recall and traceability elements
-final product labelling and coding
- incoming materials
- in-process and outgoing materials traceable
-recall system in place and tested.
GMP - water safety elements
-monitoring procedures for water and steam
- water treatment procedures to ensure potability.
GMP - warehousing elements
shipping/receiving/handling/storing/ inspection processes for dispatch and delivery
chemical storage
waste management
7 principles of HACCP
1 - Conduct a hazard analysis
2 - Identify CCPs
3 - Establish critical limits
4 - Monitor CCPs
5 - Establish Corrective Actions
6 - Varify
7 - Establish record keeping.
What does HACCP stand for?
Hazard Analysis and Critical Control Points
Was is HACCP not concerned with?
Product being out of specification.
Which process steps are monitored for HACCP?
Not every step, only those where a significant hazard exists can be considered critical control points for process control.
HACCP pre-requisites
- Food and drink safety policy (intended actions and outcomes)
- Categorisation of risk areas
- Fabrication and equipment (fit for purpose, easy to clean and maintain, regular planned maintenance)
- Supplier assurance
- Cleaning and housekeeping (scheduled and documented, including rinses)
- Staff facilities and hygiene
- Pest control
- Training
- QMS
- Product recall and traceability.
Purpose of HACCP pre-requisites
Support HACCP and minimise number of CCPs to be monitored
2 parts of HACCP risk anyalysis
Impact and Likelihood
HACCP CCP establishment flowchart - 5 questions
1 - Is the hazard managed by pre-requisite programs?
2 - Are control measures in place for the hazard?
2a - Is control at this step needed for food safety?
3 - Is the process step specifically designed to eliminate or reduce the hazard to an acceptable level? (Yes = CCP)
4 - Could contamination with the hazard occur at unacceptable levels, or increase to unacceptable levels?
5 - Will a subsequent process step eliminate or reduce the hazard to an acceptable level? (No = CCP)
HACCP - likelihood ratings & definitions
1 - low - intermittent. If uncontrolled hazard present in only 1 part of 1 batch.
2 - moderate - intermittent. If uncontrolled hazard present in all of 1 batch
3 - severe - continuous. If uncontrolled hazard present in several batches.
HACCP - impact ratings and definitions
1 - low - Consumption might cause disgust, but no adverse physical health effect
2 - moderate - consumption might cause mild adverse physical health effect or cause a health effect if consumed over an extended period.
3 - severe - consumption might
4 preparation steps for HACCP
1 - Assemble HACCP team - stakeholders and experts.
2 - Management commitment - including budget.
3 - Employee awareness - training if needed.
4 - Define the scope of the HACCP system.
6 areas included in the scope of the HACCP plan
1 - Name and description of the product(s)
2 - Target customers
3 - Intended product use by customer.
4 - Manufacturing process
5 - Hazards considered.
6 - Control of identified hazards
Define a CCP
A step or procedure in the production process where control is essential to prevent, eliminate, or reduce a hazard to an acceptable level. Established using a HACCP decision tree.
How might critical limits be defined/determined?
Legislation
Experimentally
Industry board/expert advice
CCP Monitoring - continuous automated systems - features
-Monitor all the time, so preferred over timed checks.
- Set off alarm or shut down process when if critical limit is reached.
- Failsafe fitted to alarm if monitoring stops.
Once determined, critical limits must be…?
Validated (to check they effectively manage the hazard) and validation data recorded in HACCP document.
HACCP - Principle 1
What is it, and what are the 2 steps
Hazard Analysis
- Prepare a process flow diagram (accurate and thorough)
- verify the flow diagram (staff who operate the process day to day)
HACCP - Principle 2
What is it, and what are the 3 steps?
Identify the CCPs
- Identity hazards from process flow diagram
- Analyse hazards for impact and likelihood to determine their risk (impact x likelihood)
- Identify the appropriate controls for each hazard
- Identify which of the hazards are CCPs.
HACCP - Principle 3
What is it
Establish critical limits
- max/minimum level a process must be controlled at to reduce the occurrence of a hazard to an acceptable level.
- must be measurable, observable, and possible to monitor in real time.
HACCP - Principle 4
What is it, what does it entail?
Monitor CCPs
- How, when, who will monitor, and how will it be recorded?
- Offline, in line, or on-line monitoring.
- Must ensure operation outside critical limits is caught before hazard affects product/affected product leaves.
- Set out/document plan for maintenance of monitoring equipment.
- Monitoring must be documented, covering equipment, method, & responsibility.
- Data must be reviewed to demonstrate hazard control.
HACCP - Principle 5
What is it, and what does it entail?
Establish corrective action
- If controls fail and critical limits are reached.
- How to return process to within critical limits
- What to do with any product affected
Must be validated to prevent hazard reaching the customer.
HACCP - Principle 6
What is it, and what 6 activities are included?
Verify
-Establish verification processes.
- additional analyses of attributes of hazards to be controlled.
- reviewing customer product feedback
- auditing to ensure corrective actions are being completed
- auditing pre-requisite programs to verify compliance.
-Analysis of CCP data and any deviations from critical limits.
HACCP - Principle 7
What is it and what must be included?
Establish record keeping
Documentation and records should include outcomes from the previous 6 steps, including;
- Process flow diagram
- Set of hazards to be assessed
- Plan of critical limits
- Plan of controls
- Plan for control failures
- Plan for verification of the system
Once the plan is complete, what are the initial implementation steps for HACCP?
-Training on controlling CCP and record keeping.
- CCP signage at measurement point
What would be displayed on CCP signage?
What is being measured, the critical limits, and corrective action.
What are the 2 parts of a HACCP plan review?
1 - Verification
2 - Ensuring the plan is current.
Under what 7 circumstances might a HACCP plan be reviewed?
1 - Changes to HACCP team.
2 - New product introduction.
3 - Process changes.
4 - New technology.
5 - Legislation changes.
6 - Periodic verification of system by full audit.
7 - Customer complaints regarding product safety.
In HACCP, what does validation mean?
Checking if CCPs and critical limits work as designed to control the hazard
In HACCP, what does verification mean?
Checking that the HACCP plan works in controlling food safety hazards
What does TACCP stand for, and what does it mean?
Threat Assessment and Critical Control Points
Protects from deliberate contamination along the supply chain.
What are the 10 steps in a TACCP plan?
1 - Assemble a team
2 - Develop a risk assessment methodology
3 - Develop a supply chain flow chart.
4 - Identify steps where there could be a threat to
- organisation & key staff
- operations
- product
5 - Identify risks as CCPs or CP
6 - Identify and monitor threat controls for each CCP.
7 - Develop a plan of action addressing breaches on controls, including immediate correction and corrective action
8 - Document the TACCP plan
9 - Train staff
10 - Regularly review plan
What does VACCP stand for, and what does it mean?
Vulnerability Assessment and Critical Control Points
Dishonest/economically motivated risks to supply chain
What does HARPC stand for?
Hazard Analysis and Risk Based Preventative Control
What does SALSA stand for?
Safe and Local Supplier Approval
4 important points about monitoring device locations
- must be readily accessible
- must be regularly maintained, cleaned, and inspected.
- number be appropriate for the task at hand.
- routinely calibrated
4 methods for measuring alcohol content
1 - gravity bottle
2 - hydrometer
3 - density meters (including mass flow meters)
4 - gas chromatography
What is the most accurate method of measuring alcohol content?
Measuring the density of a lab distilled sample to eliminate the effects of total or dissolved solids.
What are the 2 most common methods of measuring alcohol content?
Hydrometers or electric density meters.
Formula to work out density
Density = Mass/Volume
What is a pycnometer?
Small flask of known volume and mass which can be used to measure density.
How is alcohol % determined using a pycnometer?
At 20 degrees C weigh a sample, then weigh distilled water.
Sample weight/water weight = specific gravity
How does a density meter work?
U shaped tube oscillates at set frequency, interrupting a light beam.
The density of the liquid in the tube alters the oscillation frequency, so can be measured by the sensor.
Specific gravity is not directly measured
Apart from density, what other factor could affect the reading of a density meter?
Viscosity (by acting as a damper)
How might a density meter’s accuracy be decreased?
If it is not cleaned correctly.
If samples are not degassed
If samples are not filtered
2 main types of density meter used by distillers?
hand held - light, expensive, fragile.
in-line - quality assurance.
What are Coriolis density meters also known as?
Mass flow meters/inertial flow meters
How does a Coriolis density meter work?
Vibrations of a thin walled, bent tube which rotates around a central axis are measured.
With no mass the tube remains untwisted.
If the density increases the tube twists (inbound flow drags behind outbound)
Twisting causes phase shifts, which change the resonant frequency of the thin walled tube.
The resonant frequency is directly affected by density.
Uses for Coriolis density meters?
Distillation and blending operations where they continuously monitor the density of spirits.
2 types of chromatography
Preparative or analytical.
Purpose of preparative chromatography
A form of purification, separating components of a mixture for further use.
Purpose of analytical chromatography
Determine and quantify the relative proportions of analytes in a small sample.
What can gas-liquid chromatography be used for?
Volatile compounds (spirits)
- volatile acids
- aldehydes
- esters
- alcohols
Non-volatile compounds if qualitative conversion to volatile compounds is possible.
Specific example plate liquid samples from rectifier or concentration columns, such as fusel oil or methanol compounds.
Main components of a gas-liquid chromatography system
- sample injection port.
- flow-controlled inert carrier gas.
- temperature programmable and controlled column oven (with packed or capillary column).
- detector suitable for compounds of interest.
- temperature controlled detector oven.
- processor.
What gases might be used as a carrier gas in gas-liquid chromatography
Usually Nitrogen, argon or helium can be used.
What are the usual internal standard and detector used in gas-liquid chromatography of whisk(e)y samples?
n-butanol
flame ionised detector
What can high performance liquid chromatography be used for?
Non-volatile compounds found in fementation and maturation.
Sugars - monitor fermentation efficiency.
Tanins/lignin-degradation products - maturation.
Phenolic compounds in matured spirits.
Main components of a high-performance liquid chromatography system.
- injection loop for liquid sample.
- solvent reservoir to act as mobile phase.
- high-pressure pump
- column filled with absorbent material (stationary phase)
- suitable detector
- may or may not be housed in temperature controlled oven.
- processor.
Potential detectors used in high-pressure liquid chromatography
Refractive index detector
Fixed/variable UV/VIS detector
Fluorescent detector
Brief overview of high-pressure chromatography
High pressure pumps pass sample + solvent through column with absorbent material. Different components have different flow rates, so they separate in the column.
Processor (calibrated on known concentrations of standard solutions) measures qualities of separated compounds.
3 types of chromatography besides gas-liquid chromatography and high-pressure liquid chromatography.
paper
thin layer
ion exchange
What is Atomic Absorption Spectrometry used for?
Measure trace metal ion concentrations in products and co-products
Specific examples
- copper traces in liquid streams
- metals in organic residue
- calcium and magnesium (cause haze) in final products
Brief overview of Atomic Absorption Spectrometry
Sample is vaporised and element of interest is atomised at high temps (air or acetylene flame)
Concentration of the element is determined by measurement of light by free metallic ions created in the flame.
**Characteristic absorbance wavelengths for metal ions in AAS **
Iron
248nm
**Characteristic absorbance wavelengths for metal ions in AAS **
Copper
324.7nm
**Characteristic absorbance wavelengths for metal ions in AAS **
Potassium
766.5nm
**Characteristic absorbance wavelengths for metal ions in AAS **
Calcium
423nm
**Characteristic absorbance wavelengths for metal ions in AAS **
Magnesium
285.2nm
**Characteristic absorbance wavelengths for metal ions in AAS **
Sodium
589nm
**Characteristic absorbance wavelengths for metal ions in AAS **
Zinc
213.9nm
Main components of an atomic absorption spectrometry system.
- Hollow cathode lamp (specific to each element)
- Lenses
- Burner
- Nebuliser (vaporises sample)
- Photomultiplier detector
- Monochromator
Accuracy level of Atomic Absorption Spectrometry
0.05mg/L
Pros of Near-Infra-Red Spectrometry
Portable
High throughput
Very little sample preparation
No destruction of sample
Bulk examination of production output
Accommodate liquid and solids
Easy to used
Cons of Near Infra-Red Spectrometry
Time consuming to calibrate
Brief overview of Near Infra-Red spectrometry
NIR-LED is directed through lenses and a sample, then through a slit. It reflects off grating through a lens and on to a detector array.
3 ways to reduce and control ethyl carbamate
- only used raw material with low levels of cyanide glycoside precursors.
- aeration during continuous distillation to prevent accumulation in the sytem.
- provision of ‘sacrificial’ copper (esp in stainless steel plants)
How can ethyl carbamate be measured?
Ion chromatography can measure cyanide in raw materials and process samples.
gas chromatography linked to mass spectroscopy can measure ethyl carbamate
How can N-nitrosodimethylamine (NDMA) be measured?
Gas chromatography with thermal energy analyser detector and appropriate column packing.
Reasons to measure colour of matured/maturing spirit
Monitor maturation
Monitor casks for exhaustions
Calculate how much caramel to add
How might colour be measured?
Colourimeter - used in production and quality assurance or control.
Spectrophotometry - highly accurate, used in research and new colour formation.
Considerations when deciding on laboratory, portable, or in-line analyses methods.
- cost
- installation
- dangerous areas
- maintenance and calibration requirements
- COSHH requirements
- specialised electrical or gas supplies
- specialist contractors for installation/maintenance
- PPE/isolation needed
- Training requirements
- Interface of results with current systems
What is set out in a standard sampling plan?
-Who samples
- How samples are taken
- When samples are taken
- Frequency of sampling
- volume sampled
- how samples are stored
- how samples are analysed
Define accuracy
equal to the true value
Define precision
amount of variation in a method.
Define Repeatability (R95)
Measurement of consistency of results when using the same tools, analyst, objectives, location, conditions, etc.
Define Reproducability (R95)
AKA between-lab variations.
Consistency of results from a method using different tools, analyst, location, conditions, repetition, objectives, etc.
How to set specification ranges (tolerances)?
Use R95 or standard deviation data from SPC information to set minimum range or bandwidth
What is the global standard for laboratory practices?
ISO/IEC 17025
What is covered in lab accreditation?
- Staff competency
- Validity and appropriateness of test methods
- Traceability to national standards
- Suitability, maintenance, and calibration of equipment
- Testing environment
- Sampling, handling, and transportation of test items
- quality assurance of test and calibration data
What are the 4 benefits of using a lab with accreditation?
Commercial - customers will insist.
Technical - more accurate results.
- Lega - conformance
- Cost
Why is sensory analysis needed?
Human senses can detect some aromas in ppt, which instruments struggle to do.
Off flavours
Attribute and Source
Diacetyl/vicinal diketone (VDK)
Sweet butterscotch aroma
Source - Fermentation or lactic acid bacteria
Off flavours
Attribute and Source
Hydrogen sulphide
Rotten eggs
Source - Poor fermentation performance
Off flavours
Attribute and Source
Fusel oils
Solventy aroma
Source - Incorrect heads cut in distillation.
Off flavours
Attribute and Source
Sweaty/leathery aroma
Aroma of sweat or leather
Source - Incorrect tails cut is distillation.
Off flavours
Attribute and Source
Trichloroanisole
Musty, damp aroma.
Source - Chlorine contamination of wood in maturation.
Off flavours
Attribute and Source
Acrolein
Pungent burnt fat
Source - Infections in fermentation
Off flavours
Attribute and Source
Dimethyl sulphide and other methyl sulphides
Vegetable, cooked sweetcorn aroma
Source - From cereal raw materials, can be removed by copper in distillation.
Off flavours
Attribute and Source
Acetal (diethyl acetal)
Sweet fruity aroma
Source - Made in fermentation process and removed by copper in distillation. Presence is sign of inadequate copper in distillation plant.
Pros of a single sensory expert (master blender)
Years of experience and training
Can detect product drift
Knowledge of reasons why issues might occur.
Cons of a single sensory expert (master blender)
Availability
Pros of a sensory panel
Availability
Wide range of individual sensitivities
Cons of a sensory panel
Less expert and experienced than a master blender
Most common sensory analysis during production
Nosing
Challenges to taste tests of spirits
Numbing
Fatigue
Intoxication (Driving)
How to prepare nosing samples
Dilute to 20% ABV
Dark glasses
Narrow aperture nosing glass
Lid or watch-glass
Same type of glasses and sizes of samples
Same amount of time from pouring to sampling
3 reasons to dilute nosing samples to 20%
- Prevents alcohol burn (and therefore fatigue)
- Can encourage release of compounds
- More samples can be tested in a single session.
How to identify (mark) samples in a panel
Random 3 digits to prevent unconscious bias.
Do not give any information on potential sample faults.
Factors to control in a sensory room
- Interfering aromas (air filtration system)
- Temperature - distracts panellists and low temps can reduce aroma intensity.
- Lighting - red is most common, masking appearance of samples.
- Independence - testing booths
5 sensory panellist guidelines
- must not be unwell/impaired
- no strong flavours 30 minutes before
- no smoking 30 minutes before
- no perfumed cosmetics
- clean hands (unperfumed soap)
3 main types of sensory test used in quality assurance
Sample screening
Difference testing
Descriptive analysis and flavour profiling.
Sample screening sensory tests
Quick evaluation - often in production.
Pass/fail or grading to character.
Small panel, but high experience/product knowledge.
Subjective - so not ideal.
Difference sensory tests
Tell statistical likelihood of a difference between samples.
Mainly triangle or tetrad tests
3 specific uses for difference sensory tests
Production process changes
Batch to batch/year to year.
Customer compaints.
2 less common difference sensory tests
Duo-trio
Paired comparison
Describe a triangle difference sensory test
3 samples are presented identically (colour, size, 3 figure codes)
2 are the same, 1 is different.
Panellists pick (or guess) which is the odd sample.
Minimum 10 tests for confidence, but low experience needed.
How is statistical significance decided?
% confidence?
p=<0.05
% confidence = (1 – p value) x 100
Describe a difference from control sensory test
1 labelled control and several coded samples, including at least 1 hidden control.
Statistically compare the results for the samples with the hidden control.
Minimum 10 tests for confidence, but little skill required.
Can determine which samples are most different (unlike triangle tests)
Describe descriptive analysis and flavour profiling
Requires trained panel of min 8-10.
Time consuming and expensive.
provides detailed information on flavour character and measure of difference between samples.
Use flavour wheel to determine flavour characteristics
Profile each flavour by using score cards to indicate intensity.
Average, then plot on to radar plot/spider web diagram.
What training might a sensory panel undergo?
Identifying key flavour attributes from spiked or representative samples.
Ensure common language
3 ways to monitor sensory panel performance?
Evaluating performance in day to day tests.
Use of test samples.
Participation in sensory proficiency schemes.
Describe how you would go about developing a sensory vocabulary for a new category of spirit drink.
- group activity - develop sensory vocabulary, including off notes of a wide range of samples of the product.
- determine key flavour characteristics (flavour wheel)
- train panel to recognise and understand each attribute using samples or spiked samples.
5 major consequences of poor hygiene
- inconsistent performances of raw material processing and fermentation
- decrease in flavour quality of fermented substrate and therefore new make.
- less safe work environment (slippages)
- poor alcohol yields
- illness and disease spread
Most common bacteria (2 species)
LAB - Lactic Acid Bacteria
Pediococcus sp (cocci shape) & Lactobacillus (rod shape)
Excess LAB can lead to?
Decrease in fermentation pH, stalling fermentation activity and therefore decreasing yield and introducing undesirable flavours.
Additional effect of Pediococcus infection?
‘Ropiness’ caused by chains of exopolysaccharides.
What bacteria come from contaminated water supplies?
Enterobacter and Escherichia (aka faecal contamination bacteria)
Sources of Enterobacter and Escherichia bacteria?
Livestock near water source, or poor operator hygiene.
Effects of Enterobacter and Escherichia infection?
Parsnip aroma and other undesirable flavours.
What conditions can Enterobacter and Escherichia bacteria not survive?
pH below 4.6
ABV above 2%
2 bacteria which convert ethanol to acetic acid?
Acetobacter and Gluconobacter
Bacteria more commonly found in molasses and it’s effects?
Leuconostoc mesenteroides
Synthesises viscous polymer dextran from glucose which can block pumps and pipework.
Zymomonas
Lives on plants
Produces undesirable flavours from fructose.
Issues with wild yeast
Different flavours
Changes yield
Potentially inhibit normal fermentation process.
What compound is produced by some wild yeast which is a hazard to cultured yeast?
Zymocin
3 basic ways to control microbiological activity levels
Routine cleaning
Good hygiene practice and design
Process controls
Most vulnerable areas of production to bacterial infection?
Unfermented substrate
Yeast handling
8 good design principles for a hygienic plant?
1 - Hygienically acceptable Area away from sources of contamination.
2 - Environmental factors, such as temp and humidity.
3 - Layout designed for easy cleaning
4 - Materials used able to withstand cleaning and process.
5 - Material storage away from process equipment.
6 - Vessels and pipework constructed to hygienic standard.
7 - Ancillary equipment, fittings and joints, hygienically designed and installed.
8 - Adequate and hygienic drainage systems.
What is a biofilm?
Complex syntrophic community of different microorganisms with cells sticking to each other and a surface.
Slimy extracellular polymeric substance matrix, hard to remove as they form in layers.
Associated with organic or inorganic soil.
Precautions is dead legs are unavoidable?
- Top of pipe, air pocket instead of build up.
- Length of dead leg not more than 1/2 pipe diameter (short as possible)
- Flow into dead leg, not past if not on top.
Good pipe design for corners?
Sweeping, less prone to soil deposits.
Ideal vessel design for hygiene
Conical, with good flow and drainage.
Butt welds on straight sheets, with corners curved (rather than welded) to prevent soil build up.
Poor vessel design/cleaning challenges
Poor flow & drainage (re-deposits soil)
Square bottom doesn’t fully drain & redeposits.
Attemperators or switchers hard to clean/shadow CIP.
Poor (overlapping or right angled) welds on corners.
What is organic soil derived from?
Carbohydrates, proteins, polyphenols, and lipids.
What is inorganic soil comprised of?
Metal cations, such as calcium, magnesium, potassium, and sodium. Anions of sulphates, phosphates, silicates, carbonates, and oxalates.
Types of soil and challenges found in raw material intake and handling.
Organic
Debris
Biofilms for wet raw materials.
Spills must be cleaned up promptly, and pests controlled
Types of soil and challenges of raw material processing/wort production?
Organic
Biofilms
May raw material processing steps are favourable to microorganism growth.
Processing equipment pipes, valves, and heat exchangers can have soil build up if not sufficiently cleaned.
Most fermentation substrates not sterilised in distillation)
Types of soil and challenges found during fermentation?
Organic (yeast and protein residue)
Inorganic
Biofilm around pipework and valves.
*Traditional materials can make cleaning hard.
Shadows from internal attemperators.
Poor drainage.
High carbon dioxide levels can deactivate caustic cleaners.
High solids (if solids in fermentation)
Types of soil and challenges found in wash distillation.
Organic (yeast and protein)
Inorganic
Biofilms around the fermenter inlet.
High carbon dioxide levels.
Internal shadow from heating surfaces
Types of soil and challenges in spirit distillation
Light to no soiling - oily film.
Internal shadows from heating surfaces
4 cleaning factors
Time
Temperature
Chemical
Mechanical
Cleaning plan design will depend on 4 factors
Nature and load of soil.
Limitations of the equipment being cleaned.
Cleaning equipment.
Level of cleanliness/sanitation required.
Define mechanical cleaning actions
Physical removal of soil through pressure, or friction of turbulent flow.
Greater mechanical action gives quicker more effective cleaning.
Factors in chemical cleaning
Concentration, type, and formulation.
Cost vs effectiveness implications.
How does temperature affect cleaning?
Temperature increasing cleaning effectiveness up to an optimum point, depending on the detergent used.
Heating costs and detergent formulations must be considered. Some areas must also be cleaned cold.
What impact does time have on cleaning?
At a premium in distilling processes, so type of cleaning procedure will be designed around the time allocated.
Definition of ‘clean conditions’
All soils removed, but not all vegetative cells.
Definition of ‘hygienic conditions’
All vegetative forms of life removed, suitable for raw material processing.
Definition of ‘disinfection’
AKA sanitisation. Destruction of microorganisms, but not bacterial spores. Reduces microorganisms to an acceptable level for defined purpose.
Definition of ‘sterilisation’
Elimination of all forms of life, including microbial spores.
(live (wet) steam at a minimum temperature of 121°C for a contact time of at least 15 minutes)
2 types of CIP design
Single use and multiuse.
Multi-use CIP sytem summary
- High initial cost for vessels, instrumentation, pumps, valves, piping, and control system.
- Complex control system and instrumentation.
- High maintenance.
- Control of detergent chemicals requires complex instrumentation.
- High and variable effluent loads, when discharging entire vessels of caustic, acid, or sanitisers.
- Recovery of detergent for reuse.
Summary of single-use CIP system
- Low initial costs, due to few/no vessels, short piping routes, simpler valve arrangements and instrumentation.
- Can be portable.
- Simple controls.
- Lower maintenance.
- Simple detergent chemical instrumentation.
- Control of effluent discharges and smaller volumes.
- Reduced footprint area for CIP unit.
- No recovery of detergent or water.
- Longer cycle times due to need to make up detergent before use.
Single-use CIP process
Pre-rinse
Unrecovered - wasteful
Detergent Recirc
Recirculating water is heated and detergent either dosed into line, or buffer tank. Detergent then recirced for set time, while temperature is controlled to a set point using measurement and H/E
Post-detergent Rinse
Fresh water pushes detergent to drain.
Further detergent and rinse
Repeated using acid (shorter and cooler)
Disinfectant Rinse
Disinfectant (Sometimes PAA) dosed into freshwater stream and either left on vessels or wastefully rinsed.
Manual single-use CIP system
Often just a pump mounted on a trolley, with a small chemical dosing vessel.
Water inlet and drain return.
Suited to small operations, raise chemical handling concerns.
Multi-use CIP process
Detergent make up can happen independently to save time.
Pre-rinse
Made from recovered post-rinse water, sent to drain.
Detergent rinse
Detergent sprayed through spray balls, recirced back to tank once rinse runs to drain (conductivity)
Post -detergent rinse
Water through sprayballs, detergent returned to tank, then rinse collected in recovery tank.
Disinfectant rinsing
Disinfectant sprayed and either left on vessels or rinsed.
3 types of tank cleaning spray ball
Static spray ball
Rotary spray ball
Rotary jet head
Static spray ball
Stainless steel ball, multiple holes.
5kPa of stress, 1.5m/s velocity.
Design based on tank dimensions and function, as well as liquid level.
270° coverage for FVs to cover yeast ring.
Foam - spray upwards.
1-2 bar pressure (too high, misting, too low inefficient)
Rotary spray head
Flow causes head to spin around an axis, higher impact force than stationary.
More efficient coverage + higher impact stress = less time.
Less water used.
Rotary jet head
Impact & shear stress 104Pa
2-4 jets rotate around 2 axis, giving complete coverage.
Pre-determined pattern and speed.
5-6 (up to 12) bar
Less detergent, water, and time required.
Spray ball maintenance
Holes can become blocked.
Rotating jets may have a sensor for confirming rotation, and/or impact and time intervals to ensure they are correct.
How is soil removed by detergents?
1 - cleaning solution penetrates the soil, wetting it.
2 - chemical and physical solubilisation between detergent, water ions, soil, and cleaning agents (breaks soil into particles)
3 - Soil is removed into cleaning solution via dispersion and emulsification.
4 - soil & cleaning solution removed from area. Stabilising agents prevent re-depositing.
What affects the efficacy of disinfectants?
Microbial load
Accessibility
Physical conditions
Disinfectant concentration
Contact time
10 attributes of an ideal detergent
- Completely soluble in water
- Adequate wetting properties
- Ability to disperse and suspend solids.
- Ability to emulsify fats
- High sequestering activity
- Low foaming
- Non-corrosive
- Highly rinsable
- Biodegradable
- Non-toxic.
What is a detergent?
Formulated from a baseline of acids or alkalis, and used to clean distillery surfaces.
2 types of detergent
Acid - nitric & phosphoric, good for inorganic soil.
Alkali - sodium hydroxide (caustic soda), good for organic soil.
2 detergent additives
Surfactants
Sequestrants & chelating agents.
Purpose of surfactant detergent additives
Reduce water surface tension, increasing surface contact.
Easier wetting and soil removal.
Fatty alcohols (non-ionic)
Purpose of sequestrants and chelating agents.
Remove metal ions (from hard water or heavy metals) by forming complexes in ‘chelation’
3 chelating agents
EDTA (ethylene-diamine-tetra-acetate)
NTA (nitrile-tri-acetate)
Gluconate
2 sequestrants
Phosphonates
Polyphosphonates
Difference between chelating agents and sequestrants?
Chelating agents bind with a single metal ion, sequestering agents bind with up to 1000 (inhibiting scale crystal growth)
Properties of caustic
Used at 1-3% (supplied in bulk up to 50%)
Prime detergent for organic soiling.
Strong alkali
Works at room temperature, or heated.
Risks with caustic
In CO2 environments reaction with sodium hydroxide can cause a vacuum in vessels.
Forms sodium carbonate, which in only 10% as effective as caustic.
Caustic additions
Chelating agents and sequestrants
Oxidising agents - hydrogen peroxide useful for burnt on solids/organic deposits.
Chlorine (restricted, corrosive)
Corrosion inhibitor.
What acids are commonly used, and why?
Nitric and phosphoric - usually a blend (other acids are corrosive to stainless steel, and incompatible with other cleaning components)
Nitric - strong hydrolysing and oxidising agent, good for penetrating scale.
Phosphoric - removes scale through hydrolysis, sequestering properties for removal. Less corrosive than nitric.
What is passivation?
Removing the free iron from the surface of the metal using an acid solution, so the remaining components can form an oxidised layer for protection.
CIP Sanitisers (2)
PAA - peracetic acid
Hydrogen peroxide
Equipment requiring sanitiser
Wort heat exchangers
(Mashing vessels and FVs if left empty)
Environment sanitisers
QAC - work by surface action, cling (foam) then easy to rinse
Drain sanitisers
Dilute sodium hypochlorite solution.
Water disinfectants
Chlorine dioxide. Low concentrations, or high for biofilm.
Corrosive to stainless steel
Hot water as a disinfectant
80°C alt to PAA. After a 30 min caustic, 5-20 mins water.
Steam as a disinfectant
Wooden washbacks.
Cleaning program
Conditions, detergent, and sanitiser for raw materials processing?
High organic soil.
High temp formulated caustic with sequestering agents.
Peroxide
Cleaning program
Conditions, detergent, and sanitiser for FVs
- High level organic soil, carbon dioxide atmosphere.
- Vent CO2 then formulated caustic soda (wetting/rinsing/sequestering agents)
- Prewash and rinse
- Peracetic acid +chlorine dioxide water rinse OR hot water/steam.
Cleaning program
Conditions, detergent, and sanitiser for yeast handling plant
- High level organic soil
- Formulated caustic soda (wetting/rinsing/sequestering agents).
- Prewash and rinse
- Peracetic acid +chlorine dioxide water rinse.
Cleaning program
Conditions, detergent, and sanitiser for process pipework
- Variable soil levels, complex (valves, fittings, bends)
- Formulated caustic soda (wetting/rinsing/sequestering agents), at high temps (65-85 degrees)
- Hot water or PAA flush
Cleaning program
Conditions, detergent, and sanitiser for wash stills
- High level of organic soil, carbon dioxide atmosphere.
- Remove CO2, then formulated caustic soda (wetting/rinsing/sequestering agents). Sacrificial pre-wash then rinse.
- No sanitiser.
Cleaning program
Conditions, detergent, and sanitiser for spirit stills
- Low level organic, heavy alcohols and oils.
- Hot water rinse between runs, quarterly maintenance clean formulated caustic soda (wetting/rinsing/sequestering agents).
- No sanitiser
Cleaning program
Conditions, detergent, and sanitiser for spirit processing plant (BVs, etc)
- Low level organic soiling, some product residue.
- Formulated caustic soda (wetting/rinsing/sequestering agents), then product grade water rinse.
- No sanitiser.
CIP QC checks
Monitor - temp, pressure, jet validation, flow rate, conductivity.
Maintain vessels and CIP equipment - physical inspection, sensor cleaning and calibrating, spray balls.
Operator - rinse checks for detergent and ATP.
Visual checks
Lab checks - rinse samples and swabs.
Analytical detection methods (CIP)
Spread plate/pour plate/streak plate methods.
ATP bioluminescence.
Pros of ATP
- Compact and easy to use.
- Targeted kits available.
Cons of ATP
No standard units.
Calibration required
Wash contains ATP so gives a false positive.
SAQ
Explain why managing microbial contamination is important in a distillery.
- Inconsistent performance of ferm and raw mat. processing.
- Decrease in flavour quality.
- Less safe working environment (spills).
- Poor alcohol yields.
- Illness and disease in greater community (eg, Legionella)
