As of 2024, it is estimated that around 10% of the UK population follows a gluten-free or reduced gluten diet. This translates to approximately 6.8 million people, based on the current population statistics (Coeliac UK). The growth in this dietary choice reflects a significant market for gluten-free products, driven by both medical needs, such as those of individuals with coeliac disease, and lifestyle preferences.
This ever-growing market is proving increasingly tempting for brewers, and with a few simple tweaks to the processing, brewers can achieve beers with less than the required 20 ppm of gluten with little or no noticeable difference in appearance and flavour.
Here are our top tips for successful gluten-free brewing:
- Grist Adjustment
- Processing
- Use of DeHaze
- Avoidance of Cross-Contamination
- Get the Testing Regime Right
Grist Adjustment
It sounds simple but managing how much gluten you put into the beer in the first place is crucial. Gluten is a composite of storage proteins found in the endosperm of grains alongside starches. Some grains contain more gluten than others, with wheat containing the most, followed by barley and rye.
Adjusting the grist with wheat reduction in mind will help greatly reduce gluten content. Adding cereal adjuncts like maize, rice, sorghum, and millet can bulk up the gravity without adding gluten. Brewing sugars, such as invert and syrups, can also increase the gravity while adding zero gluten.
The nitrogen content of malted barley relates to the gluten content. Talk to your maltster about options for nitrogen content from season to season to keep this aspect of your malt consistent.
Processing (Especially Copper Finings)
Effective protein management during processing can reduce gluten content in the final beer. Starting with the brewing liquor, ensuring your mash pH and temperature hit your spec is important. The effect of changes in malt quality can be minimized with the addition of enzymes like Trizyme to the mash. A good rolling boil with wort well-fined with carrageenan will reduce protein levels in the wort and gluten content.
In partnership with Brampton Brewery, Murphy and Son Survey (fig 1) established that a correct boil with optimized copper finings can drop gluten content of the beer by as much as 30%.
Post fermentation, extended conditioning at low temperatures helps reduce protein and gluten content by encouraging protein to drop out with polyphenol complexes. This process can be sped up with the addition of finings and silica gels.
Use of DeHaze
DeHaze is a proline-specific endo-protease that offers a great solution for both gluten removal and prevention of protein-polyphenol complexes formation, major causes of chill and permanent haze.
DeHaze is popular because it is easy to dose, typically 1-5g per hl, added directly to the wort on collection in the fermenting vessel. Addition at this point is beneficial as it mixes well and during a normal vigorous fermentation, yeast will naturally consume some of the smaller peptides, preventing potential stability issues down the line.
Avoidance of Cross-Contamination
If you are not an exclusive gluten-free brewer, consider the effects of cross-contamination across the plant. Implementing procedures to prevent cross-contamination of raw materials is vital.
Consider factors like gluten carryover from skimmed/cropped yeast and contamination across filtration runs. Making your gluten-free beer the first beer processed following a deep clean will also help eliminate pick-ups across the process.
These issues should also be considered if you use third-party packaging companies. Ensure that all documentation such as HACCPs, standard procedures, and training records are up to date to include any new steps in the process, especially as beer usually starts with gluten-containing ingredients.
Get the Testing Regime Right
Managing the testing regime when producing gluten-free beer is a challenging task. The recommended starting point for any brewer is to try and produce a beer similar to the gluten-free product and test to ensure that the beer is below 20 ppm before product launch.
This may seem costly but will help iron out any issues and reduce risk before launching a new product. The current recognized test for gluten in beer is the ELISA (Enzyme Linked Immunosorbent Assay) R5 competitive test, which uses antibodies to test for gluten in beer.
This test must be conducted by an accredited laboratory. Samples are prepared in triplicate by degassing and centrifugation. They are incubated at exactly 22°C for 30 minutes along with several laboratory standard samples. A wash solution is then added to each sample, followed by a substrate pink chromogen. After a second incubation period, a “stop solution” is added, and the sample is exposed to light of wavelength 450 nm. The gluten content is inversely proportional to the absorption of this light, and the data from all triplicate samples and standards are used to plot a graph to determine the ppm of gluten.
Best practice is to test every batch of beer for gluten content as late as possible in the process. Many brewers test in tank before packaging, but some retailers now insist extra tests are carried out on the final packaged product. This is a difficult and time-consuming process but necessary due to the potential risk to public health.
We have a dedicated lab, technical team, and gluten testing regime available at Murphy and Son to help you get free-from ready. If you would like more information on pricing, sending in a sample, and technical support available, visit https://www.murphyandson.co.uk/our-laboratory-services/chemistry-microbiological-tests/
Gluten-free brewing can be a challenging process to handle, but with careful management in the brewery and a few relatively minor tweaks, it is possible to produce great-tasting beers with no noticeable changes in character.
With an increasing number of people moving away from food and drink containing gluten, when done well, this can be a great success for any brewer and provide a greater range of beer for people following such a diet to enjoy!