Proficiency testing schemes in brewing

The benefits of proficiency testing schemes in brewing

By Gordon Jackson - November 2019

There are many proficiency testing schemes available to the food and drink industry. Participation in such schemes provides confidence that laboratory analytical results are meaningful and accurate, helping to ensure consistency in the quality of the food or drinks produced and their safety. There are several suggested benefits associated with proficiency testing schemes, but how do they really affect or benefit brewers? We asked a group of leading technical experts for their feedback on one long-established proficiency testing scheme.

The Brewing Analytes Proficiency Scheme – what it aims to do

The Brewing Analytes Proficiency Scheme (BAPS) is an international scheme designed to promote quality in the measurement of a range of chemical, microbial and sensory analytes in beer, and to help participants monitor and improve the quality of their measurements. BAPS is accredited by the United Kingdom Accreditation Services (UKAS) and is a partnership between LGC Standards and Campden BRI, and has over 350 participants.

The scheme was set up in 1994 with the aim of helping brewers to:

Under BAPS, participants are sent samples to analyse using their in-house methods and the results are sent back to the scheme organisers. Each participant then receives a report comparing their performance with that of all other participants.

Participants can receive samples for the analysis of:

Full details of tests undertaken with BAPS are shown in Appendix 1.

So, what do the brewers really use it for?

There are many uses of the data from proficiency testing. On the 25th anniversary of the BAPS scheme we took a look at how its participants use the results (data) on the chemical analysis, microbial analysis and the sensory analysis of beer. The aim was to understand how brewers use the proficiency scheme and the benefits they realise from it. The survey targeted the 11 members of the BAPS Advisory Group, which comprises leading figures from the world’s brewing companies, who steer the scheme to ensure that it meets the requirements of the 350 companies that take part in its proficiency testing.

The key results from the survey were:

For chemical analysis of beer

Samples of commercial beers are sent to participants. Homogeneity is checked before samples are sent to them. As shown in Appendix 1, chemical analysis includes samples for lager/ale, lager, dark/craft ale, alcohol free/low alcohol beers and low-level gluten beers. However, in this survey we did not distinguish between the different samples types and just considered them all under the general heading of chemical analyses.

Here’s how the chemical analysis findings were used:

For microbiological analysis of beer

The BAPS microbiological test materials contain organisms typically found in the brewing industry. These are sent out as freeze-dried organisms and participants can identify these to a basic level (e.g. bacteria or yeast), intermediate level (e.g. lactic acid bacteria) or advanced level (e.g. lactobacillus brevis). The survey showed that:

For sensory analysis of beer

Participants in BAPS receive samples of commercial beers; they evaluate various aroma and taste characteristics and compare their results (both quantitatively and qualitatively) with the consensus of other taste panels and also with the performance of individual tasters in other taste panels. The results of the survey showed that:

Other uses

In addition to the specific uses mentioned above, some further and generic uses were identified by participants, including:


The results of the survey show the variety of uses for results from proficiency testing schemes:

Appendix 1

The full range of tests available with the Brewing Analytes Proficiency Scheme (BAPS):

Chemistry Analyte
Lager/ale Alcohol by volume, Bitterness, Carbon dioxide, Colour at 430nm, Gravity (apparent, original, present), Haze (0ºC, 20ºC), Original extract, pH, Refractive index, Sulfur dioxide, Total gas pressure.
Lager 2-Methyl butanol, 3-Methyl butanol, 2+3 Methyl butanol. Acetaldehyde, Calcium, Carbohydrate (total), Chloride, Copper, Diacetyl as VDK, Dimethyl disulfide, Dimethyl sulfide, Energy value (kcal), Energy value (kJ), Ethyl acetate, Ethyl hexanoate, Foam stability (HRV), Free alpha amylase, Free diacetyl, Free 2,3-pentanedione, Glucose, Hydrogen sulfide, Iron, Iso-alpha-acids, Iso-amyl acetate, Iso-butanol, Magnesium, Maltose, Maltotetraose, Maltotriose, Methanethiol, Methylthioacetate, Nitrate, n-Propanol, Phosphate, Polyphenols (total), Potassium, Sodium, Sulfate, Tetra-iso-alpha-acids, TSN, Zinc
Dark/craft ale Alcohol by volume, Bitterness, Colour at (430nm, 530nm), Diacetyl as VDK, Free 2,3-pentanedione, Free diacetyl, Iso-alpha-acids, Tetra-iso-alpha-acids.
Alcohol free/low alcohol beer Alcohol by volume (qualitative, quantitative), Bitterness, Colour at 430nm, Gravity (apparent, present), pH.
Low level gluten beer Gluten
Microbiology Analyte
Lyophilised material High level/ low level Identity of organisms, Lactic acid bacteria count, Total aerobic bacterial count, Total aerobic microbial count. Total anaerobic microbial count, Wild yeast, count: Identity of organisms.
Sensory Analyte
Lager/ale Alcoholic/Solvent, Astringent, Bitter, Body, Burnt, Caramel, Cereal, DMS, Fruity/ Citrus, Fruity/Estery, Hop, Linger, Malty, Other sulfur, Oxidised/Aged, Sour, Sweet, and others.

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