By Dante Moroni

Gluten free beers made with grains other than barley such as sorghum, rice, or corn have their own unique flavor profiles. There is a marked, often distasteful, difference compared to that of traditional barley beers. For this reason, some brewers have taken on the challenge of crafting what’s referred to as “gluten-reduced” beer. The brewing process is done the same way that regular barley beer is made, with one important addition. They add something known as Brewers Clarex,⁴ an enzyme that can break down any gluten proteins left in the final product.¹ The result is a beer indiscernible from regular beer, with markedly lower gluten content. Interestingly, many brewers use the enzyme to clear the cloudy haze from their beer and aren’t even thinking about gluten. This could be one of the reasons some traditional beers have surprisingly <20ppm gluten.

Image – Favobacterium meningosepticum: https://fineartamerica.com/featured/flavobacterium-meningo-septicum-bacteria-cnriscience-photo-library.html

Brewer’s Clarex is also known as AN-PEP or Proline-Specific Peptidase. It was discovered and isolated from Flavobacterium meningosepticum bacteria around 44 years ago³ and is now a readily available commercial enzyme. It has been shown to fully degrade any immunogenic gluten peptides in solution through cleaving bonds between the amino acid proline and others in the peptide chain.¹ These proline residues are frequent in the 33-mer highly immunogenic component of Gliadin, a sub-component of gluten, and are the main immune stimulating component of gluten.² There is concern that the remaining fragments aren’t readily detectable by current testing methods. However, since proline residues are where the main immunogenic epitopes of gluten are located, these fragment should not induce an immune response. Further, these small peptide fragments are likely rapidly degraded by digestive enzymes.

Some examples of beers that have been made with Brewers Clarex are Omission and Stone IPAs. Unfortunately, the fact that they’re made with barley still shy’s away most people on a gluten free diet (GFD). In addition, these beers cannot be labelled “gluten-free” per FDA guidelines. Although brewer’s can use terms such as “gluten-reduced” or “crafted to removed gluten”.⁵

Altogether, in my opinion, having the option to drink delicious tasting barley beers that have had their gluten proteins degraded by Brewer’s Clarex is a great option for serious beer connoisseurs following a GFD. Finally, individuals with celiac disease should still consult with their physician before consuming these beers.

Cheers!

References

1. Akeroyd M, Zandycke S, Hartog JD, Mutsaers J, Edens L, Berg M, Christis C. AN-PEP, Proline-Specific Endopeptidase, Degrades All Known Immunostimulatory Gluten Peptides in Beer Made from Barley Malt. Journal of the American Society of Brewing Chemists. 2016;74:91-99.
2. Arentz-Hansen H, Mcadam SN, Molberg O, Fleckenstein B, Lundin K, Jorgensen T, Jung G, Roepstorff P, Sollid L. Celiac Lesion T Cells Recognize Epitopes That Cluster in Regions of Gliadins Rich in Proline Residues. Gastroenterology. 2002;123:803-809.
3. Yoshimoto T, Tsuru D. Proline Specific Endopeptidase from Flavobacterium. Agricultural and Biological Chemistry. 1978;42:2417-2419.
4. Brewers Clarex PDF -https://brewshop.no/images_hovedside/Brewers%20Clarex%20-%20The%20same.%20Only%20Simpler.pdf
5. Food Labeling; Gluten-Free Labeling of Fermented or Hydrolyzed Foods. Food and Drug Administration. Federal Register. 2020.