Ask Mr. Wizard

Denatured Enzymes

TroubleShooting

Joe Fleischman • Tampa, Florida asks,
Q

I’ve heard raising the grain bed above 168 ºF (76 ºC) for a mash-out denatures the enzymes and helps “fix” a beer’s fermentable profile. However, I’m a frequent visitor to one of the many beer forums out there and this idea was bashed. Can you please shed some light on this? It has always been my understanding that the enzymes are heat
labile over a period of time. For example, take a typical single infusion mash held at 154 ºF (68 ºC) for 60 minutes, then a mash-out for 15 minutes at 170 ºF (77 ºC). What is happening to my enzymes, have they been denatured at the mash out?

A
Hey Joe . . . I heard you cooked your old alpha amylase down . . . how are you going to mash now? I guess if you believe the threads about
Response by Ashton Lewis.