Enzymatic production of gluten-free beers from conventional grains

Enzymes, Extracts, Other Session
Aaron Hanson, BunsenBrewers, Estacada, OR

ABSTRACT: Gluten sensitivity affects an estimated 6% of the general population, leaving many unable to drink beers fermented from conventional grains. Gluten sensitivity is caused by a T-cell driven intolerance to wheat gluten epitopes. Gluten epitopes are proline rich and are vulnerable to enzymatic degradation by prolyl oligopeptidases. Aspergillus niger prolyl endoprotease (AN-PEP) has been shown to efficiently degrade gluten by post-proline cleavage. Studies have also shown AN-PEP to be active at pH ranges from 2 to 8, with peak enzymatic activity at pH 5–5.5. Enzymatic degradation of gluten in pre-boil wort by AN-PEP may be achieved, producing gluten-free beers with conventional grains. Gluten degradation occurs by cooling the wort to 37°C as it is transferred from the mash tun to the kettle, and whirlpooling the 37°C wort with the AN-PEP enzyme until gluten degradation is complete. The wort is then boiled as normal, with the AN-PEP denaturing before fermentation occurs. The end result is gluten-free beer with the flavor profile of a conventional grain recipe.

Aaron Hanson received a B.S. degree in biochemistry from the University of Minnesota in Minneapolis, MN. He is currently a brewer in the Portland area.