Mash and hot-side aeration

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Exo

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Do I have to be worried about this? I try real hard to gently pour my runnings back in with as little splashing as possible...but then I see 170deg. water being poured over the grains...hehe.

Why not worry about this? Because boiling gets rid of that bad aeration or?
 
Absolutely, you must be very wworried about hot-side-aeration.
Many respected people have published articles showing how bad it is.

On the other hand, other respected people say otherwise.

For myself, I did an experiment some while ago when I just dumped a mash into the lauter tun from a great height (I mash and sparge in separate tuns) and didn't care how much I splashed the runings while recirculating.

I can't taste any difference in the finished product (unless the HSA'd brew is in the next keg to be drunk). I did 4 brews that week, and only one got the special treatment. It is possible that I mixed up the carboys while kegging. If so - I shall post when I open the next keg.

By the way, I'm talking about ESB here. Different types of beer may respond differently.

-a.
 
There's something about hot-side aeration that people seem to overlook. When I'm sparging, I'm not being careful or quiet about how i let the sparge water hit the top of the water in the cooler. I use a Phil's sparger, and all of those streams shoot right onto the top of the mash water. Of course, this isn't actual wort doing the spashing, but I'd imagine that O2 is O2, no matter how it gets into the wort. The grain bed is a good filter, but it's certainly not going to filter oxygen.

On the flip side of this, when people are talking about aerating the wort after it's cool and before pitching, they comment on how ineffective splashing is when you're trying to aerate your wort.

I don't personally have a big opinion on hot-side aeration since I don't know too much about it, so I'm not trying to start any controversy. Because I have heard that it's the "right thing to do" i try to be as careful as possible when transferring my wort while it's hot. But in my ten years of brewing, I haven't noticed any problems.
 
If your aerating the wort and you are ready to pitch your yeast, you don't gently splash , you shake the s--t out of it . Or a oxy stone or aeration pump will to the trick. The diff is a 20 min stone job or 5 min shake job. I've always done the shake meathod and pitched starters, I have never had fermenting go longer than 12 hours without starting. As for run off and mash. Does'nt the boil take all the oxygen out of the wort? Is this not the reason we have to aerate the wort befor pitching? I personaly would not worry!
 
This sounds very complicated and makes my head hurt thinking about it. I don't think the hot water hitting the grains from a sparge-arm height will matter. At that point it's just water and there's nothing to get oxidized.

Sounds as though something(wort) has to be in solution for the oxygen atoms to cling to/react.
 
gabe said:
If your aerating the wort and you are ready to pitch your yeast, you don't gently splash , you shake the s--t out of it . Or a oxy stone or aeration pump will to the trick. The diff is a 20 min stone job or 5 min shake job. I've always done the shake meathod and pitched starters, I have never had fermenting go longer than 12 hours without starting. As for run off and mash. Does'nt the boil take all the oxygen out of the wort? Is this not the reason we have to aerate the wort befor pitching? I personaly would not worry!

Boiling do take o2 out but HSA actually binds o2 to other molecules changing their structure. It is this that causes the off flavors associated such as
a cardboardy taste and the long term storage of our brew.
Not everyone can taste any effects that HSA can contribute so if you are one of them, then RDWHAHB.
I try to lessen anything that can potentially mar my brew. So I try to miniminize any splashing before cooling that I can.
 
boo boo said:
a cardboardy taste and the long term storage of our brew.

Personally, I've never tasted cardboard.:p
The only thing I've ever tasted like I imagine cardboard would taste like is a Southern English Brown Ale.
The concept of long term storage is something I don't understand.:drunk:

-a.
 
gabe said:
The diff is a 20 min stone job or 5 min shake job. I've always done the shake meathod and pitched starters

Nope, an oxygen stone aerates the wort MUCH better and faster than shaking. You cannot get the amount of oxygen in your wort with 20 minutes of shaking that you can get into it with 30 minutes of pure oxygen.

Anyway, I still think my point about sparge water should be taken into consideration. Of course, your sparge water isn't wort, but if it's pulling oxygen into your lautering process, then those oxygen atoms can react with components of the wort. Theoretically, anyway. And if your wort is exposed to the air at all, some amounts of oxygen WILL dissolve into it. And when you are running off into your boil pot, it's certainly coming into contact with the air. A little splashing is hardly causing extra problems.
 
Steve973 said:
Nope, an oxygen stone aerates the wort MUCH better and faster than shaking. You cannot get the amount of oxygen in your wort with 20 minutes of shaking that you can get into it with 30 minutes of pure oxygen.

30 minutes of pure oxygen? Did you mean 30seconds?
 
You know? Since I started using the Oxygenator with 3 15-second bursts I haven't had any blow-off's of a primary vessel?
 
OK, my .02 worth on this. Oxygen can infuse itself the hot wort during a mash, but it really isn't that big of a concern unless you are whipping up a froth during transfer or addition of infusion water, or during sparging. I've also heard that a full vigorous boil helps get rid of this oxygen, and can minimize this.
 
ajf said:
Personally, I've never tasted cardboard.:p
The only thing I've ever tasted like I imagine cardboard would taste like is a Southern English Brown Ale.
The concept of long term storage is something I don't understand.:drunk:

-a.

I have never tasted it either and as for long term storage, I hear you, lol.

Biermann.. Like I said, boiling do rid the brew of o2 but when HSA is introduced into the wort , it alters the composition of some of the molecules that cause the features such as staling and off flavors, and boiling don't get rid of it.

For the record, I have never tasted HSA in any beer, mine or any other. I only go by what other well respected authors/senior brewers have published on the subject and I trust what so many have said about it to the point of trying to minimize any HSA that I can.
 
I believe we've come to an understanding on this subject:

While it's possible to get Hot-side aeration during the mash process it is unlikely. However, do as much as possible to prevent excess splashing. Oh yea, and RDWHAHB!
 
WORD:fro:

I've never had a problem with HSA. Ever. Of course, I've never really whipped a beer up to a frothing mess either. Not to say it can't happen, though.

I used to be an organic chemist. Maybe I'll float this one by my old advisor. . . HSA I'm sure has to do with oxidation of various organic compounds that is basically irreversible. Although this may happen on a small scale at the molecular level, it won't cause a significant problem if one is careful. And the longer and the more dissolved O2 you leave in solution , the more likely you are to get HSA. Boiling gets rid of this excess dissolved O2.


Oh, and a bit :off: , I just bought a SS conical!!! :rockin:

Sorry, just had to throw that in.
 
I've had issues where the output barb on my mash cooler wasn't very good, and i got some bubbles in the line. These would increase until I would move the tube around to let these air bubbles out. in that instance, each and every part of my wort would come into some contact with air, and I can't say that my beer suffered from it. An interesting experiment would be to use an oxygen stone in your collected wort before you boiled it. Of course, you risk losing a six hour brew day, and who wants to drink cardboard, whatever that would taste like?
 
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