Oxidation During Boil

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RipeforYelp22

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Hey all, I'm a new brewer, currently waiting one more week to bottle my second batch (I'm skipping the secondary this time around as many of you helpful brewers have advised me to do).

So I'm reading Palmer's How To Brew, and he points out how you shouldn't vigorously stir the boiling wort because it can cause oxidation and thus off flavors. He goes on to say that you should only aerate the wort once it reaches fermentation temperature. Is this true?

I'm kinda nervous because I stirred my boiling wort pretty vigorously during both my 1st and 2nd batches. The first batch is all gone, and it was tasty, though I did notice the slightest hint of a semi-sour aftertaste. Nobody else seemed to notice it but me and my BF, the ones who brewed the beer. The clarity also could have been better, but I'm hoping this is an issue that will be resolved with leaving the wort in the primary for the entire duration of fermentation.

One last Q: my BF's (pompous) friend has been brewing for a bit over a year, and I'm reluctant to say that his "Royal ***** IPA" is one of the best I've ever tasted. His beer tastes so unbelievably clean, clear and refreshing. Are there any steps I can take to achieve the refreshing finish I'm seeking? And how likely is it that oxidation is occurring during my boil? Thanks in advance!
 
I've never heard about not stirring boiling wort. . . .and why would you anyway. Plus. There is nothing at all wrong with secondary's. It's a fallacy that they are BAD. Not necessary but not actually BAD. There is no O2 after the boil anyway. That is why you aerate after you cool it.
 
Yeah, best not to worry about it. In the future, know that the vigorous boil stirs for you pretty well.

For that clean flavor you seek - fermentation temp control. That should be your next investment. Whether it's a swamp cooler, ebay temp controller box, or Ranco/JC digital thermostat, you gotta keep those temps stable.
 
Well, oxidation wouldn't lead to perceived sourness, so I don't think that's at play here. You _might_ be seeing early stages of infection. Or you might be jumping at shadows, like many new brewers do. ;)

Regarding stirring while boiling: to be honest, unless you're in danger of boiling over, I'd leave your wort well enough alone during the boil. There's just no real need to touch it, other than to occasionally scrape a little hop residue back off the side of the pot and into the wort.

Now - if you want to get nice a clean ale, a lot of that comes from yeast choice and a lot of it from fermenting conditions - both temperature and time. Many ale yeasts just ferment cleaner than others. In general, cooler temperatures tend to result in cleaner fermentations. And the more time you can give your beer, within reason, the cleaner and clearer it will tend to be.

If you don't currently have a reliable method to accurately control your fermentation temperature, that's something to start researching and planning for. Do some searches around here for swamp coolers (a good, inexpensive way to get relatively good temperature control) or fermentation chambers (a better, yet more expensive way to get very good temperature control). Both will go a long way to improving your beers.
 
This is another one of those little "gems" that worst cased scenarioed and unconsciously scared a whole legion of new brewers. It's the old HSA boogeyman.

Like tytanium said, don't worry about it. There's been a lot of experiments and such that really showed that it's a worry with little merit. The Basic Brewing Folks along with BYO magazine have done research and found that it's overblown.

Your going to NEED to be introducing oxygen before you pitch yeast anyway....

Even commercially I don't think folks worry too much about it.

These guys aren't.



If you do a search on here you will find out that HSA is really a bogeyman for the homebrewer, and no one really worries about it....

https://www.homebrewtalk.com/f36/hot-side-aeration-so-im-idiot-71873/

https://www.homebrewtalk.com/f12/who-afraid-hsa-76779/

https://www.homebrewtalk.com/f13/hot-side-aeration-71806/

Our beer is hardier than most new brewers think it is....

Concentrate on the really important things, Temp control, sanitization, pitching the right amount of yeast, letting the yeast do it's thing with plenty of time to clean up after itself, and worry less about all those things Palmer warned you about. Our beer is pretty resiliant stuff, it doesn't go bad if we look at it crosseyed, that sometimes I think Palmer's writing style would lend us to believe.
 
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boiling temps aren't a problem because the boiling is actually driving the Oxygen away.

The temps close to boiling, when O2 is not being driven off are the temps that were supposedly a problem. However, nowadays Hot Side Aeration has been shown to not be anywhere near a problem that is was suspected of being.

So much so that people are now advised to not worry about it at all. I still am more or less "gentle" with the hot wort, but if necessary I am not averse to splashing it.

The fact is, you can do a whole lot more damage by aerating the wort after fermentation and prior to bottling. You should practice reasonable caution when splashing at that time.
 
Oxidated wort is REQUIRED for yeast health, but is detrimental once that wort has alcohol in the solution.

ALL you have to know:

OXIDATION at any point PRIOR to active fermentation = GOOD
OXIDATION at any point AFTER active fermentation starts = BAD
 
You guys know your ****! I'm definitely gonna use a swamp cooler for my next batch in a week or two and see if that makes a difference. Should the t-shirt be soaked all the way through, or should the top remain dry? And I'll try my best to leave the boiling wort alone just to be safe. Thanks!
 
Oxidated wort is REQUIRED for yeast health, but is detrimental once that wort has alcohol in the solution.

ALL you have to know:

OXIDATION at any point PRIOR to active fermentation = GOOD
OXIDATION at any point AFTER active fermentation starts = BAD


for small beers; yes... For Very Big Big Beers you actually need to add 02 the first 48 hours of Fermentation to keep the yeast healthy/strong so they can chug out all the Sugars....
 
for small beers; yes... For Very Big Big Beers you actually need to add 02 the first 48 hours of Fermentation to keep the yeast healthy/strong so they can chug out all the Sugars....

It's first 24 for big beers not 48.....You don't want to exceed 24 because it is highly likely that beyond that fermentation is indeed occurring, and therefore there is alcohol present.
 
I have another Q which stems from How To Brew: for extract brewing, do you add all your extract at once at the beginning of the boil, or do you add half at the beginning and wait till there's 5 minutes left to add the second half in order to reduce the chances of Maillard reactions/off-flavors?
 
So as I stated, I'm on the fence a little. Even Jamil has a show on HSA. So I'm wondering if its something to think about if your going to be storing beer for some time, say over a year? This would explain why most don't have to worry about it.
 
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