Lesson 4 - Wort and Beer Analysis

Confidence in the results from a lab is essential. We use the results from the lab to inform decisions on quality, safety, and compliance with legislation, so we need to be sure that what we think to be true is true. If we are using an external lab, we need evidence that the lab competence is externally validated. In this section we will discover the standards for laboratory practice and schemes which labs use to check their performance against their peers. We begin by looking at lab standards.

ISO/IEC 17025

The global standard for laboratory practice is ISO/IEC 17025: The General Requirements for the Competence of Testing and Calibration Laboratories. It is important to note that laboratories are accredited against ISO/IEC 17025 rather than being certified.  

In certification, the external assessment body confirms that the organisation is in compliance with its procedures. This is done at a documentary level. So, as long as you have the correct records you can be certified. In accreditation, the external assessment body confirms that the lab is capable of performing certain tasks to a defined standard. Even national and government labs are required to comply with ISO/IEC 17025.

Accreditation will cover these criteria:

• Technical competence of staff

• Validity and appropriateness of test methods

• Traceability of measurements and calibrations to national standards

• Suitability, calibration, and maintenance of test equipment

• Testing environment

• Sampling, handling, and transportation of test items

• Quality assurance of test and calibration data

The accreditation body for ISO/IEC 17025 is typically the national laboratory accreditation organisation. The International Laboratory Accreditation Cooperation (ILAC) represents accreditation bodies from across the world.

A full list of accrediting bodies for all countries can be found on their website: https://ilac.org/signatory-search/

ISO/IEC 17025 is similar in structure to ISO 9001 (which you will remember from the Quality Assurance and Quality Management lesson) and was last updated in 2017. Like 9001, ISO/IEC 17025 has continuous improvement at its heart. There are five clauses, of which the technical requirements are most pertinent to the analytical activities of the lab.

1. Scope

2. Normative references

3. Terms and definitions

4. Management requirements – QMS etc.

5. Technical requirements – see below

The technical requirements clause is summarised below and outlines what is required in terms of calibration, equipment, traceability, and sampling: 

As with a QMS, each element will have a set of policies, procedures, records, and corrective actions associated with them. ISO/IEC 17025 is fast replacing local or national schemes for lab accreditation but there are still some in place. We do not have the time to discuss them here but if you ask in the brewery lab, they will be able to give you the details of those in your country.

So, what are the benefits of accreditation? Here is a list:

1. Commercial. Large customers will insist on accredited lab results so having accreditation provides access to this market.   

2. Technical. If your equipment or analytical reagents are produced and tested by an accredited lab your results will be more accurate.

3. Legal. For certain food-safety or compliance analyses lab accreditation is essential.

4. Cost. Having the framework of an accredited system in place will reduce the frequency of retesting which will reduce cost per analysis.

Good laboratory practice (GLP)

The formal definition of GLP is “a set of principles intended to assure the quality and integrity of non-clinical laboratory studies that are intended to support research or marketing permits for products regulated by government agencies”. You may question how this could relate to brewing. The term has also come to mean the practices which need to be followed to ensure validity of data from laboratories, almost like a QMS for the lab. For this reason, all the elements of GLP like equipment, calibration, validation, training, safety, sampling design, and traceability are seen in ISO/IEC 17025.

Now we have covered the basis of accreditation, we look at how labs can check themselves against their peers.

Proficiency testing (or ring testing)

We use interlaboratory checks to determine if the results from one lab for a particular attribute are acceptable when compared with other laboratories using the same or possibly different methods. Proficiency testing is covered by ISO/IEC 17043 the Conformity Assessment – the General Requirements for Proficiency Testing.  

In basic terms, proficiency testing is where a group of labs receive identical samples. They all analyse the samples using the same technique and submit results. The results are collated and analysed statistically. The results are then published so each lab can see how it performed compared to the other labs. Some benefits of participating in proficiency schemes are:

• Monitoring the effectiveness of the laboratory quality systems

• Comparing the laboratory's measurements with those of peers

• Demonstrating competence to stakeholders such as auditors, regulators, and customers

• Monitoring trends in measurements over time

• Monitoring technician capability as part of training and assessment

• Confirming analytical proficiency of laboratory personnel within the same facility or across multiple sites

• Evaluating the use of alternative methods of analysis

• Improving accuracy of information used for labelling

There are several brewing-analyses proficiency schemes worldwide. The best subscribed scheme for the brewing industry is the Brewing Analytes Proficiency Scheme (BAPS) which is run jointly by the Laboratory of the Government Chemist (LGC) and Campden BRI. As well as being the UK’s designated National Measurement Institute for chemical and bioanalytical measurements, LGC has offices across the globe.

In BAPS, samples are sent to breweries every four weeks and the breweries can opt to only carry out analyses of interest. Breweries undertake the analysis and submit their results via an online portal. The scheme covers microbiological, sensory, and physicochemical analyses.  The results of all breweries are then published along with the assigned value. The assigned value is not the ‘right’ answer but the median of participant results after the removal of statistical outliers.

Why do you think proficiency testing schemes do not get an accredited and competent lab to analyse the samples that are sent out and then use its results as the ‘right’ answer?   Give yourself 5-10 minutes to think about this, and then click ’Next’ to continue with this lesson.