Denaturing Enzymes?

[Microphobik]

I have come across references to denaturing enzymes. I was wondering if someone can explain that to me. It sort of sounds like the idea is that if you get the mash too hot then the enzymes are effectively ruined and will not convert your starches. But i wasn't sure if that was right.

I had a recent batch were my mash temp started to drop too much so I gave it some gas and then spaced out for a few minutes only to come back and see that it was up around 180. I brought it down as quickly as possibly but that batch finished with a pretty high final gravity (1.022, when it should have been around 1.014). I am assuming I basically ruined the enzymes from that point on but wasn't sure and was hoping someone could enlighten me a bit on this topic.

Thanks in advance.

 

[LandoLincoln]

Yes, certain enzymes denature (the molecules fall apart) at certain temps. Beta amylase enzymes denature at temps exceeding 154° F. Alpha amylase enzymes denature at around 165° and higher. Mash temp ranges are pretty tight, whereas every other temperature range for brewing is a lot more forgiving.

There's lots and lots that you can read about the different enzymes of mashing, what they do and at what temps they work best at. "How to Brew" by John Palmer has a free version of his book online.

 

[JimRausch]

Yeah, you cooked it. Think of denaturing enzymes as unwinding them. Enzymes have to be in a particular shape in order to work properly- like a key fitting into a lock. When you denature a protein you change the shape, and it doesn't work.
BUT, denaturing your enzymes, if done before they have finished their work, will influence your starting gravity, but Not your final gravity. After all, when we mash out by increasing the temp, we do that in order to denature the enzymes and stop any further conversion. So, every time we mash, we denature those buggers at the end. Was your OG what you predicted? You need to look elsewhere to explain your FG being higher than expected(yeast health, yeast pitching rate, fermentation temps, length of time of fermentation).

 

[day_trippr]

[...]
BUT, denaturing your enzymes, if done before they have finished their work, will influence your starting gravity, but Not your final gravity.[...]

Not sure that's correct if full conversion had yet to be achieved. On the way to denaturing temperatures the mash will tend towards dextrin production, which will add unfermentables to the resulting wort...

Cheers!

 

[Sir-Hops-A-Lot]

Could this be stuck fermentation?
Some yeasts tend to get stuck at 1.020 FG. It might not have been your mash temp.
Or maybe you are right. Then perhaps an aggressive attenuating yeast will get the FG down further. Saison yeasts often do this. Whereas a common yeast such as Saf-05 might go to 1.014, the saison would go further. I got my saison down to about 1.005. It may give your beer an added taste that will make your free-loading friends say "wow! That's unique!"

 

[JimRausch]

Not sure that's correct if full conversion had yet to be achieved. On the way to denaturing temperatures the mash will tend towards dextrin production, which will add unfermentables to the resulting wort...

Cheers!

Agreed. That's why I wondered what the OP's OG was. And I guess dextrin production would be partially determined by how quickly he increased the temp to that 180*. And, I suppose if that temp was uniform throughout the mash. It was an interesting Q,wasn't it.

 

[vineyardbmw]

Agreed. That's why I wondered what the OP's OG was. And I guess dextrin production would be partially determined by how quickly he increased the temp to that 180*. And, I suppose if that temp was uniform throughout the mash. It was an interesting Q,wasn't it.

My thoughts exactly. Hot pockets are a big problem with consistency. Stir baby stir. You'll be surprised what your temp actually stabilizes at. With hot pockets you'll get a good mix of highly fermentable sugars and dextrins. I love adding Brett B to the keg/ bottling bucket and let her sit, no sugar, with a beer that's apparently under attenuated. Yummmmm barnyard!

 

[JimRausch]

My thoughts exactly. Hot pockets are a big problem with consistency. Stir baby stir. You'll be surprised what your temp actually stabilizes at. With hot pockets you'll get a good mix of highly fermentable sugars and dextrins. I love adding Brett B to the keg/ bottling bucket and let her sit, no sugar, with a beer that's apparently under attenuated. Yummmmm barnyard!

I have to admit- I'm a little scared of Brett. Sounds like once you use it, it's hard to get rid of in your brewing environment. Have not tried anything brewed with it, so not sure I would like it. The description(barnyard,earthy) doesn't sound very appetizing. And I'm a large animal Vet, so I like that smell. Taste, I don't know.

 

[vineyardbmw]

I have to admit- I'm a little scared of Brett. Sounds like once you use it, it's hard to get rid of in your brewing environment. Have not tried anything brewed with it, so not sure I would like it. The description(barnyard,earthy) doesn't sound very appetizing. And I'm a large animal Vet, so I like that smell. Taste, I don't know.

I have two completely different sets of soft goods (anything plastic) that I quarantine in separate areas. As long as you practice good sanitization techniques you should have no issues. Also. Anything Brett or wild in any way I use kegs and bottles clearly marked so. As to the barnyard flavor. It is mostly esters so it is more in the nose. You'll be surprised how well the hint of flavor goes with a good beer. Try "Brux" it's a Russian River and Sierra Nevada collaboration. I love it. I'm sure there are many more Brett only that you could try. Relax don't worry.....

 

[billl]

Keep in mind, denaturing is not instantaneous. The OP ramped the temp up over a period of time. The first enzyme to be impacted would be Beta because it denatures at a lower temp. The long it is held at a denaturing temp, the greater percentage of the enzyme gets ruined. The alpha was at denaturing temps for a shorter period of time. Since alpha is responsible for the less fermentable sugars, having relatively more alpha doing the conversion leads to a less fermentable wort.